Danfoss Optyma Plus Controller for Condensing Unit User Guide

The controller regulates the condensing temperature by adjusting
the difference between condensing temperature and ambient
temperature. The setpoint can be changed using the upper and lower
buttons. For night operation, the reference can be raised to reduce
fan noise.

2. Fan Operation:

The controller maintains the condensing temperature above
outdoor temperature by controlling the fan speed. Users can define
fan control settings in menu ‘F17’. Fan speed at start and low
loads can be adjusted using specific functions.

3. Liquid Injection:

The controller can activate liquid injection into the economizer
port if the discharge temperature approaches the maximum allowable
level. Note that this function uses the Aux Relay if
configured.

4. Low Pressure Monitoring:

The internal low pressure monitoring function cuts out the
compressor if suction pressure falls below the lower limit after
the minimum ON time is exceeded. An alarm (A2) is issued in such
cases.

5. Pump Down Limit:

The compressor stops if suction pressure falls below a set value
after the minimum ON time is exceeded.

6. Separate Thermostat Function:

The taux sensor can be used for heating functions with
programmable temperature settings, where the AUX relay connects the
heating element.

7. Digital Inputs:

DI1: Starts and stops compressor
DI2: Various user-selectable functions

DI3: Safety signal from low/high-pressure switch

Frequently Asked Questions (FAQ):

Q: How can I adjust the fan speed at startup?

A: You can set the fan speed at startup using the ‘Jog Speed’
function, and it will be maintained for 10 seconds before changing
to the required regulation speed.

Q: What happens if the compressor detects low suction
pressure?

A: The compressor will be cut out by the low pressure monitoring
function if suction pressure falls below the lower limit after
exceeding the minimum ON time, and an alarm (A2) will be
issued.

“`

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User Guide
Controller for condensing unit OptymaTM Plus
SW Ver. 3.7x
www.danfoss.com

User Guide | Controller for condensing unit, OptymaTM Plus
Introduction
Application
Condensing unit control
Advantages · Condensing pressure control in relation to outside temperature · Fan variable speed regulation · On/off or variable speed regulation of the compressor · Heating element control in crankcase · Day/night controller operation · Built-in clock function with power reserve · Built-in Modbus data communication · Monitoring discharge temperature td · Oil return management control at variable speed control
Principle The controller receives a signal for demanded cooling, and it then starts the compressor. If the compressor is controlled by variable speed, the suction pressure (converted to temperature) will be controlled according to a set temperature value. Condenser pressure regulation is performed again following a signal from the ambient temperature sensor and the set reference. The controller will then control the fan, which allows the condensing temperature to be maintained at the desired value. The controller can also control the heating element in the crankcase so that oil is kept separate from the refrigerant. For excess discharge temperature, the liquid injection will be activated in the suction line (for compressors with the liquid injection option).
Functions · Control of condensing temperature · Control of fan speed · On/off control or speed regulation of the compressor · Control of heating element in crankcase · Liquid injection into economizer port (if possible) · Raising the condenser pressure regulation reference during night
operation · Extern start/stop via DI1 · Safety cut-out activated via signal from automatic safety control
Regulation reference for condensing temperature The controller controls the condensing Reference, which is in detail the difference between condensing temperature and ambient temperature. The reference setpoint can be shown with a brief push on the middle button and adjusted with the upper and lower button. The reference can be raised at night to allow slower fan speeds to reduce fan noise. This is done via the night set back feature.
This setting can be changed without entering the programming mode so care needs to be taken to not adjust unintentionally.
Day/Night The controller has an internal clock function which changes between daytime and night operation. During night operation, the reference is raised by the ‘Night offset’ value. This day/night signal can also be activated in two other ways: · Via an on/off input signal – DI2 · Via data communication.

Reference

Night offset

Set Point Tamb

Day

Night

Day

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User Guide | Controller for condensing unit, OptymaTM Plus
Fan operation The controller will control the fan so that the condensing temperature is maintained at the desired value above the outdoor temperature.
The user may select from different ways to control the fan:
· Internal speed regulation Here the fan is speed-controlled via terminal 5-6. At a need of 95% and above, the relay on terminal 15-16 are activated, while 5-6 are deactivated.
· External speed regulation For larger fan motors with insufficient internal outlet, an external speed regulation can be connected to terminal 54-55. A 0 10 V signal indicating the desired speed is then sent from this point. The relay on terminal 15-16 will be active when the fan is in operation.
In menu ‘F17’ the user can define which of the two controls to use.

Fan speed at start When the fan is re-started after an idle period, it will be started at a speed that is set in the ‘Jog Speed’ function. This speed is maintained for 10 seconds, after which the speed changes to the regulation need.
Fan speed at low loads At low loads between 10 and 30%, the speed will remain at that which is set in the ‘FanMinSpeed’ function.
Fan speed at low ambient temperatures To avoid frequent start/stops in low ambient temperatures in which the fan’s capacity is high, the internal amplification factor is lowered. This provides a smoother regulation. The ‘Jog speed’ is also lowered in the area from 10 °C and down to -20 °C. At temperatures below -20 °C the ‘Jog Low’ value can be used.

Speed Jog Min.
Speed Jog
Jog low

Compressor compartment pre-ventilation The condenser fan starts and operates for a period of time and speed before the compressor starts. This happens in case of any mildly flammable refrigerant selected via “o30 Refrigerant”, to get a safe atmosphere while sucking potential flammable A2Lrefrigerant gas out of the compressor compartment. There is a fixed delay of about 8 seconds between this preventilation and compressor start in order to reduce the airflow significantly and avoid any condensing problems on low ambient temperatures.
© Danfoss | Climate Solutions | 2025.07

15 16 54 55
15 16
Required capacity
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User Guide | Controller for condensing unit, OptymaTM Plus

Compressor control The compressor is controlled by a signal at the DI1 input. The compressor will start once the input is connected. Three restrictions have been implemented to avoid frequent start/ stops: – One for minimum ON time – One for minimum OFF time – One for how much time must elapse between two starts. These three restrictions have the highest priority during regulation, and the other functions will wait until they are complete before regulation can continue. When the compressor is ‘locked’ by a restriction, this can be seen in a status notification. If the DI3 input is used as a safety stop for the compressor, an insufficient input signal will immediately stop the compressor. Variable speed compressors can be speed-controlled with a voltage signal at the AO2 output. If this compressor has been running for a long period at low speed, the speed is increased for a short moment for the purpose of oil-return.
Maximum discharge gas temperature The temperature is recorded by sensor Td. If variable speed control is chosen for the compressor, this control will initially reduce the compressor capacity if the Td temperature approaches the set maximum value. If a higher temperature is detected than the set max. temperature, the fan’s speed will be set to 100%. If this does not cause the temperature to drop, and if the temperature remains high after the set delay time, the compressor will be stopped. The compressor will only be re-started once the temperature is 10 K lower than the set value. The above mentioned re-start restrictions must also be complete before the compressor can start once again. If the delay time is set to ‘0’, the function will not stop the compressor. The Td sensor can be deactivated (o63).
Liquid injection into economizer port The controller can activate the liquid injection into economizer port if the discharge temperature is approaching the maximum allowable temperature. Note: Liquid injection function use the Aux Relay if the relay is configured to this function.
High pressure monitoring During regulation, the internal high pressure monitoring function is able to detect an over the limit condensing pressure so that the regulation can continue. However, if the c73 setting is exceeded, the compressor will be stopped and an alarm is triggered. If, on the other hand, the signal comes from the interrupted safety circuit connected to DI3, the compressor will immediately be stopped and the fan will be set to 100%. When the signal is once again ‘OK’ at the DI3 input, the regulation will resume.

Low pressure monitoring During regulation, the internal low pressure monitoring function will cut out the compressor upon detecting a suction pressure that falls below the lower limit, but only once the minimum ON time is exceeded. An alarm will be issued (A2). This function will be time delayed, if the compressor starts at low ambient temperature.
Pump down limit The compressor will be stopped if a suction pressure that falls below the set value is registered, but only once the minimum ON time is exceeded.

Alarm overview

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DI off: Di3 => A97 / DI2=1 => A97
© Danfoss | Climate Solutions | 2025.07

User Guide | Controller for condensing unit, OptymaTM Plus

Heating element in the crankcase The controller has a thermostat function which can control the heating element for the crankcase. Oil can thus be kept separate from the refrigerant. The function is active when the compressor has stopped. The function is based on the ambient temperature and suction gas temperature. When the two temperatures are equal ± a temperature difference, power will be supplied to the heating element. The ‘CCH off diff’ setting indicates when power will no longer be supplied to the heating element. The ‘CCH on diff’ indicates when 100% power will be sent to the heating element. Between the two settings the controller calculates the wattage and connects to the heating element in a pulse/pause cycle which corresponds to the desired wattage. The Taux sensor can be used to record the temperature in the crankcase if desired. When the Taux sensor records a temperature lower than Ts+10 K, the heating element will be set to 100%, but only if the ambient temperature is below 0 °C.
Separate thermostat function The taux sensor can also be used in a heating function with programmable temperature. Here, the AUX relay will connect the heating element.
Digital inputs There are two digital inputs DI1 and DI2 with contact function and one digital input DI3 with high voltage signal. They can be used for the following functions: DI1: Starts and stops compressor DI2: Here the user can select from various functions
Signal from an external safety function External main switch / night setback signal / separate alarm function / Monitoring of input signal / signal from an external speed control DI3: Safety signal from low/high-pressure switch
Data communication The controller is delivered with built-in MODBUS data communication. If a different form of data communication is requested, a LON RS485 module can be inserted in the controller. The connection will then be made on terminal RS 485. Important All connections to the data communication must comply with the requirements for data communication cables. See literature: RC8AC.
Display The controller has one plug for a display. Here display type EKA 163B or EKA 164B (max. length 15 m) can be connected. EKA 163B is a display for readings. EKA 164B is both for readings and operation. The connection between display and controller must be with a cable which has a plug at both ends. A setting can be made to determine whether the Tc or Ts is to be read out. When the value is read out, the second read-out can be displayed by briefly pressing the lower button. When a display is to be connected to the built-in MODBUS, the display can advantageously be changed to one of the same type, but with Index A (version with screw terminals). The controllers address must be set higher than 0 in order for the display to be able to communicate with the controller. If connection of two displays is required, one must be connected to the plug (max. 15 m) and the other must then be connected to the fixed data communication.
Override The controller contains a functions which can be used together with the override function in the master gateway/system manager.

100% 0% CCH on diff
DI1 DI2 DI3 N
MODBUS MOD
Max. 15 m
Function via data communication Function in gateway/system manager Used parameters in OptymaTM Plus

CCH off diff

tamb – Ts

L LP HP
N
LON RS
LON Max. 1000 m
MOD
Address o03 > 0 Day/Night schedule Day/Night control / Time schedule — Night setback

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User Guide | Controller for condensing unit, OptymaTM Plus

Survey of functions

Function
Normal display
The display shows the temperature value for the suction pressure Ts or from the condensing pressure Tc. Enter which of the two are to be displayed in o17. During operation, when one of the two is shown in the display, the other value can be seen by pressing and holding in the lower button.
Thermostat
Set point The controller’s reference Tc is the outside temperature + set point + any applicable offset. Enter the set point by pressing the middle button. A offset can be entered in r13.
Unit Set here if the display is to show SI-units or US-units 0: SI (°C and bar) 1: US (°F and Psig).
Start / stop of refrigeration With this setting refrigeration can be started, stopped or a manual override of the outputs can be allowed. (For manual control the value is set at -1. Then the relay outlets can be forcecontrolled by the respective reading parameters (u58, u59 etc.). Here the read value can be overwritten.) Start / stop of refrigeration can also be accomplished with the external switch function connected to a DI input. If the external switch function is deselected, the input must be shorted. Stopped refrigeration will give a “Standby alarm”.
Night setback value The controller reference is raised by this value when the controller switches to night operation.
Reference Ts Here the reference is entered for the suction pressure Ts in degrees (only for OptymaTM Plus inverter)
Reference Tc Here the current controller reference for condensing pressure Tc can be read out in degrees.
External heating function Thermostat cut-in value for an external heating element (only when 069=2 and o40=1) The relay activates when the temperature reaches the set value. Relay releases again when the temperature has increased by 5 K (the difference is set at 5 K).
Minimum condensing temperature (lowest permitted regulation reference) Here the lowest permitted reference is entered for the condensing temperature Tc.
Maximum condensing temperature (highest permitted regulation reference) Here the highest permitted reference is entered for the condensing temperature Tc.

Para- Parameter by operation via data meter communication
Ts / Tc
Thermostat control Reference
r05 Unit °C=0. / °F=1 (Only °C on AKM, whatever the setting)
r12 Main Switch 1: Start 0: Stop -1: Manual control of outputs allowed
r13 Night offset
r23 Ts Ref
r29 Tc Ref r71 AuxTherRef
r82 MinCondTemp r83 MaxCondTemp

Maximum discharge gas temperature Here the highest permitted discharge gas temperature is entered. The temperature is measured by sensor Td. If the temperature is exceeded, the fan will be started at 100%. A timer is also started which can be set in c72. If the timer setting runs out, the compressor will be stopped and an alarm will be issued. The compressor will be reconnected 10 K below the cut-out limit, but only after the compressor’s off timer has expired.
Alarm

r84 MaxDischTemp
Night setbck (start of night signal. 0=Day, 1=Night) Alarm settings

The controller can give alarm in different situations. When there is an alarm all the lightemitting diodes (LED) will flash on the controller front panel, and the alarm relay will cut in.

With data communication the importance of the individual alarms can be defined. Setting is carried out in the “Alarm destinations” menu via AKM.

Delay of a DI2 alarm

A28 AI.Delay DI2

A cut-out/cut-in input will result in alarm when the time delay has been passed. The function

is defined in o37.

High condensing temperature alarm limit The limit for the condensing temperature, set as difference above the instant reference (parameter r29), at which the A80 Alarm is activated after expired delay (see parameter A71). Parameter is set in Kelvin .

A70 Air flowDiff

Delay time for alarm A80 – see also parameter A70. Set in minutes.

A71 Air flow del

Reset alarm

Ctrl. Error

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User Guide | Controller for condensing unit, OptymaTM Plus

Compressor

Compressor control

The start/stop of the controller can be defined in several ways. Internal only: Here, only the internal main switch in r12 is used. External: Here, input DI1 is used as a thermostat switch. With this setting, input DI2 can be defined as an ‘external safety’ mechanism that can stop the compressor.

Running times To prevent irregular operation, values can be set for the time the compressor is to run once it has been started. And for how long it at least has to be stopped.

Min. ON-time (in seconds) Min. OFF-time (in seconds)

c01 Min. On time c02 Min. Off time

Minimum time between cut-in of relay (in minutes)

c07 Restart time

Pump down Limit Pressure value at which the compressor stops

c33 PumpDownLim

Compressor min. speed Here the minimum allowable speed for the compressor is set.

c46 CmpMinSpeed

Compressor start speed The compressor will not start before the required speed can be achieved

c47 CmpStrSpeed

Compressor max. speed Upper limit for compressor speed

c48 CmpMaxSpeed

Compressor max. speed during night operation Upper limit for compressor speed during night operation. During night operation, the c48 value is reduced to the percentage value set here

c69 CmpMax % Ngt

Definition of compressor control mode 0: No compressor – Condensing unit OFF 1: Fixed speed – Input DI1 used to start / stop of fixed speed compressor 2: Variable speed – Input DI1 used for start / stop of variable speed-controlled compressor with a 0 10 V signal on AO2

c71 Comp mode

Delay time for high discharge gas temperature (in minutes) When sensor Td records a temperature higher than the limit value entered in r84, the timer will start. When the delay time expires, the compressor will be stopped if the temperature is still too high. An alarm will also be issued.

c72 Disch. Del

Max. pressure (Max. condensing pressure) The maximum permitted condensing pressure is set here. If the pressure increases, the compressor will be stopped.

c73 PcMax

Difference for max. pressure (Condensing pressure) Difference for re-start of compressor if it is cut out due to PcMax. (All timers must expire before re-start is permitted)

c74 Pc Diff

Minimum suction pressure Enter the lowest permitted suction pressure here. The compressor is stopped if the pressure drops below the minimum value.
Suction pressure difference Difference for re-start of compressor if it is cut out due to PsLP. (All timers must expire before re-start is permitted)
Amplification factor Kp for compressor regulation If the Kp value is lowered, the regulation will be slower
Integration time Tn for compressor regulation If the Tn value is increased, regulation will run more smoothly
Liquid Injection Offset The liquid injection relay is activated when the temperature is over “r84” minus “c88” (but only if the compressor is running).

c75 PsLP c76 PsDiff c82 Cmp Kp c83 Comp Tn sec c88 LI Offset

Liquid Injection hysterese The liquid injection relay is then deactivated when the temperature has dropped to “r84” minus “c88” minus “c89”.

c89 LI Hyst

Compressor stop delay after Liquid injection Compressor ON-time after relay “Aux relay” is went OFF

c90 LI Delay

Desired compressor speed in connection with pressure transmitter faults. Speed during emergency operation.

c93 CmpEmrgSpeed

Min On time during Low Ambient Temperature and Low Pressure Measured Tc for which the Comp min speed is raised to StartSpeed The LED on the controller’s front will show whether refrigeration is in progress.

c94 c94 LpMinOnTime c95 c95 TcSpeedLim

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User Guide | Controller for condensing unit, OptymaTM Plus

Fan
Amplification factor Kp If the KP value is lowered, the fan speed will change.
Integration Time Tn If the Tn value is increased, the fan speed will change.
Amplification factor Kp max The regulation uses this Kp, when the measured value is far from reference
Fan speed The actual fan speed is read out here as a % of nominal speed.
Change in fan speed A permitted change in fan speed can be entered for when the fan speed is to be lowered. The setting can be entered as a percentage value per second.
Jog speed Set the fan’s start-up speed here. After ten seconds the function jog function will stop and the fan speed will then be controlled by the normal regulation.
Jog speed at low temperatures Enter the desired jog speed for outside temperatures of -20 °C and lower here. (For outside temperatures between +10 and -20, the controller will calculate and utilise a speed between the two jog settings.)
Fan control definition 0: Off 1: The fan is connected to terminal 5-6 and is speed-controlled by an internal phase cut. The
relay on terminal 15-16 connects at speed requirements of 95% or higher. 2: The fan is connected to an external speed control device. The speed control signal is
connected to terminals 28-29. The relay on terminal 15-16 will connect when regulation is required. (During external control, the settings F14, F15 and F16 will remain in force)
Minimum fan speed Set the lowest permitted fan speed here. The fan will be stopped if the user enters a lower speed.
Maximum fan speed The fan’s top speed can be limited here. The value can be entered by setting the nominal speed of 100% to the desired percentage.
Manual fan speed control An override of the fan speed control can be performed here. This function is only relevant when the main switch is in service mode.
Phase compensation The value minimises the electrical noise emitted during phase control. The value should only be changed by specially trained staff.
The condenser fan will pre-ventilate the compressor compartment to ensure a safe environment before compressor start on selected A2L-refrigerants via o30
The LED on the controller’s front will show whether Fan is in progress supplied either through fan speed control output or fan relay.

Fan control n04 Kp factor n05 Tn sec n95 Cmp kp Max F07 Fan Speed % F14 DownSlope F15 Jog Speed F16 LowTempJog
F17 FanCtrlMode
F18 MinFanSpeed F19 MaxFanSpeed F20 Manual Fan % F21 Fan Comp F23 FanVent Time

Real time clock
When using data communication the clock is automatically adjusted by the system unit. If the controller is without data communication, the clock will have a power reserve of four hours.

(Times cannot be set via data communication. Settings are only relevant when there is no data communication).

Switch to day operation Enter the time at which the control reference becomes the entered set point.
Change to night operation Enter the time at which the control reference is raised with r13.

t17 Day start t18 Night start

Clock: Hour setting

t07

Clock: Minute setting

t08

Clock: Date setting

t45

Clock: Month setting

t46

Clock: Year setting

t47

Miscellaneous
If the controller is built into a network with data communication, it must have an address, and the system unit of the data communication must then know this address.

Miscellaneous

The address is set between 0 and 240, depending on the system unit and the selected data o03 communication.

The function is not used when the data communication is MODBUS. It is retrieved here via

o04

the system’s scan function.

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Access code 1 (Access to all settings)

o05 Acc. code

If the settings in the controller are to be protected with an access code you can set a

numerical value between 0 and 100. If not, you can cancel the function with setting 0 (99 will

always give you access).

Controller software version

o08 SW ver

Select signal for the display Here you define the signal to be shown by the display. 1: Suction pressure in degrees, Ts. 2: Condensing pressure in degrees, Tc.

o17 Display mode

Pressure transmitter settings for Ps Working range for pressure transmitter – min. value Pressure transmitter settings for Ps Working range for pressure transmitter – max. value

o20 MinTransPs o21 MaxTransPs

Refrigerant setting (only if “r12” = 0) Before refrigeration is started, the refrigerant must be defined. You may choose between the following refrigerants 2=R22. 3=R134a. 13=User defined. 17=R507. 19=R404A. 20=R407C. 21=R407A. 36=R513A. 37=R407F. 40=R448A. 41=R449A. 42=R452A. 39=R1234yf. 51=R454C. 52=R455A
Warning: Wrong selection of refrigerant may cause damage to the compressor. Other refrigerants: Here setting 13 is selected and then three factors -Ref.Fac a1, a2 and a3 via AKM must be set.

o30 Refrigerant

Digital input signal – DI2

o37 DI2 config.

The controller has a digital input 2 which can be used for one of the following functions:

0: The input is not used.

1: Signal from a safety circuit (short-circuited =ok for compressor operation). Disconnected =

compressor stop and A97 alarm).

2: Main switch. Regulation is carried out when the input is short-circuited, and regulation is

stopped when the input is put in pos. OFF.

3: Night operation. When the input is short-circuited, there will be regulation for night

operation.

4: Separate alarm function. Alarm will be given when the input is short-circuited.

5: Separate alarm function. Alarm will be given when the input is opened.

6: Input status, on or off (DI2 status can be tracked via data communication).

7: Alarm from the compressor’s external speed control.

Aux relay function 0: The relay is not used 1: External heating element (temperature setting in r71, sensor definition in 069) 2: Used for liquid injection (temperature setting in r84) 3: Oil return management function must activate the relay Pressure transmitter settings for PC Working range for pressure transmitter – min. value Pressure transmitter settings for PC Working range for pressure transmitter – max. value

o40 AuxRelayCfg
o47 MinTransPc o48 MaxTransPc

Select the type of condensing unit. Factory set. After the first setting, the value is ‘locked’ and can only be changed once the controller has been reset to its factory setting. When entering the refrigerant setting, the controller will ensure that the ‘Unit type’ and refrigerant are compatible.

o61 Unit type

S3 Configuration 0 = S3 input not used 1 = S3 input used for measuring of discharge temperature

o63 S3 config

Save as factory setting With this setting you save the controller’s actual settings as a new basic setting (the earlier factory settings are overwritten).

o67 –

Define the use of the Taux sensor (S5) 0: Not used 1: Used to measure oil temperature 2: Used to measure the temperature of the external heating function 3: Other use. Measuring of optional temperature
Period time for heating element in crankcase Within this period the controller will itself calculate an OFF and ON period. The time is entered in seconds.
Difference for the heating elements 100% ON point The difference applies to a number of degrees below the ‘Tamb minus Ts = 0 K’ value
Difference for the heating elements full OFF point The difference applies to a number of degrees above the ‘Tamb minus Ts = 0 K’ value

o69 Taux Config
P45 PWM Period P46 CCH_OnDiff P47 CCH_OffDiff

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User Guide | Controller for condensing unit, OptymaTM Plus

Operating time for condensing unit The condensing unit’s operating time can be read out here. The read-out value must be multiplied by 1,000 in order to obtain the correct value. (The displayed value can be adjusted if required)
Operating time for the compressor The compressors operating time can be read out here. The read-out value must be multiplied by 1,000 in order to obtain the correct value. (The displayed value can be adjusted if required)
Operating time for heating element in crankcase The heating element’s operating time can be read out here. The read-out value must be multiplied by 1,000 in order to obtain the correct value (the displayed value can be adjusted if required).
Number of HP alarms The number of HP alarms can be read out here (the displayed value can be adjusted if required).
Number of LP alarms The number of LP alarms can be read out here (the displayed value can be adjusted if required).
Number of discharge alarms The number of Td alarms can be read out here (the displayed value can be adjusted if required).
Number of blocked condenser alarms The number of blocked condenser alarms can be read out here (the displayed value can be adjusted if required).
Oil return management Speed limit If the compressor speed exceeds this limit, a time counter will be increased. It will be decreased if the compressor speed falls down below this limit.
Oil return management time Limit value of the above described time counter. If the counter exceeds this limit, the compressor speed will be raised to the boost speed.
Oil return management Boost speed This compressor speed ensures that the oil returns to the compressor
Oil return management Boost time. The time the compressor must operate at Boost speed

P48 Unit Runtime
P49 Comp Runtime
P50 CCH Runtime
P51 HP Alarm Cnt P52 LP Alarm Cnt P53 DisAlarm Cnt P90 BlckAlrm Cnt P77 ORM SpeedLim P78 ORM Time P79 ORM BoostSpd P80 ORM BoostTim

Service Read pressure Pc Read temperature Taux Status on DI1 input. On/1=closed Status on night operation (on or off ) on =night operation Read Superheat Read temperature at S6 sensor Read the compressor capacity in % Status on DI2 input. On/1=closed Status on relay for compressor Status on relay for fan Status on relay for alarm Status on relay “Aux” Status on relay for heating element in crankcase Status on input DI3 (on/1 = 230 V) Read condensing pressure in temperature Read pressure Ps Read suction pressure in temperature Read ambient temperature Tamb Read discharge temperature Td Read suction gas temperature at Ts Voltage on the analogue output AO1 Voltage on the analogue output AO2

Service u01 Pc bar u03 T_aux u10 DI1 status u13 NightCond u21 Superheat SH u36 S6 temp u52 CompCap % u37 DI2 status u58 Comp Relay u59 Fan relay u62 Alarm relay u63 Aux Relay u71 CCH Relay u87 DI3 status U22 Tc U23 Ps U24 Ts U25 T_ambient U26 T_Discharge U27 T_Suction U44 AO_1 Volt U56 AO_2 Volt

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User Guide | Controller for condensing unit, OptymaTM Plus

Operating status

The controller goes through some regulating situations where it is just waiting for the next point of the regulation. To make these “why is nothing happening” situations visible, you can see an operating status on the display. Push briefly (1s) the upper button. If there is a status code, it will be shown on the display. The individual status codes have the following meanings:

Normal regulation

When the compressor is operating it must run for at least x minutes.

When the compressor is stopped, it must remain stopped for at least x minutes.

Refrigeration stopped by main switch. Either with r12 or a DI-input

S10

Manual control of outputs

S25

No refrigerant selected

S26

Safety cut-out Max. condensing pressure exceeded. All compressors stopped.

S34

(Measurement) Ctrl. state:
0 2 3 10 25 26 34

Other displays:

Password required. Set password

Regulation is stopped via main switch

OFF

No refrigerant selected

ref

No type has been selected for the condensing unit.

typ

Fault message

In an error situation the LED’s on the front will flash and the alarm relay will be activated. If you push the top button in this situation you can see the alarm report in the display. There are two kinds of error reports – it can either be an alarm occurring during the daily operation, or there may be a defect in the installation. A-alarms will not become visible until the set time delay has expired. E-alarms, on the other hand, will become visible the moment the error occurs. (An A alarm will not be visible as long as there is an active E alarm). Here are the messages that may appear:

Code / Alarm text via data Description communication

Action

A2/— LP alarm

Low suction pressure

See instructions for the condensing unit

A11/— No Rfg. sel.

No refrigerant selected

Set o30

A16 /— DI2 alarm

DI2 alarm

Check the function that sends a signal at the DI2 input

A17 / —HP Alarm

C73 / DI3 Alarm (High / low pressure alarm)

See instructions for the condensing unit

A45 /— Standby mode

Standby position (stopped refrigeration via r12 or DI1-input) r12 and/or DI1 input will start the regulation

A80 / — Cond. blocked

Air flow has decreased.

Clean the condensing unit

A96 / — Max Disc. Temp

Discharge gas temperature is exceeded

See instructions for the condensing unit

A97 / — Safety alarm

Safety function on DI2 or DI 3 is activated

Check the function that sends a signal at the DI2 or DI3 input and the direction of rotation of the compressor

A98 / — Drive alarm

Alarm from speed regulation

Check speed regulation

E1 /— Ctrl. Error

Faults in the controller

E20 /— Pc Sensor Err

Error on pressure transmitter Pc

E30 /— Taux Sensor Err

Error on Aux sensor, S5

E31/—Tamb Sensor Err

Error on air sensor, S2

Check sensor and connection

E32 / —Tdis Sensor Err

Error on discharge sensor, S3

E33 / —Tsuc Sensor Err

Error on suction gas sensor, S4

E39/— Ps Sensor Err

Error on pressure transmitter Ps

Data communication The importance of individual alarms can be defined with a setting. The setting must be carried out in the group “Alarm destinations”

Settings from
System manager High Middle Low Log only Disabled

Settings from

Log

AKM (AKM destination)

Alarm relay

Send via

Non

High

Low-High

Network

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User Guide | Controller for condensing unit, OptymaTM Plus

Operation

Display The values will be shown with three digits, and with a setting you can determine whether the temperature is to be shown in °C or in °F.

Cutout alarm relay / receipt alarm/see alarm code · A short press of the upper button
If there are several alarm codes they are found in a rolling stack. Push the uppermost or lowermost button to scan the rolling stack.

Light-emitting diodes (LED) on front panel The LED’s on the front panel will light up when the relevant relay is activated.
= Refrigeration = heating element in crankcase is on = Fan running
The light-emitting diodes will flash when there is an alarm. In this situation you can download the error code to the display and cancel/sign for the alarm by giving the upper button a brief push.
The buttons When you want to change a setting, the upper and the lower button will give you a higher or lower value depending on the button you are pushing. But before you change the value, you must have access to the menu. You obtain this by pushing the upper button for a couple of seconds – you will then enter the column with parameter codes. Find the parameter code you want to change and push the middle buttons until value for the parameter is shown. When you have changed the value, save the new value by once more pushing the middle button. (If not operated for 20 (5) seconds, the display will change back to the Ts/Tc temperature display).
Examples
Set menu 1. Push the upper button until a parameter r05 is shown 2. Push the upper or the lower button and find that parameter you
want to change 3. Push the middle button until the parameter value is shown 4. Push the upper or the lower button and select the new value 5. Push the middle button again to freeze the value.

Set point 1. Push the middle button until the temperature value is shown 2. Push the upper or the lower button and select the new value 3. Push the middle button again to conclude the setting.
Reading the temperature at Ts (if Tc is the primary display) or Tc (if Ts is the primary display) · A short press of the lower button
Get a good start
With the following procedure you can start regulation very quickly:
1 Open parameter r12 and stop the regulation (in a new and not previously set unit, r12 will already be set to 0 which means stopped regulation.
2 Select refrigerant via parameter o30
3 Open parameter r12 and start the regulation. Start/stop at input DI1 or DI2 must also be activated.
4 Go through the survey of factory settings. Make any necessary changes in the respective parameters.
5 For network. – Set the address in o03 – Activate scan function in the system manager.
Note When delivering the condensing unit, the controller will be set to the condensing unit type (setting o61). This setting will be compared with your refrigerant setting. If you select a “nonpermitted refrigerant”, the display will show “ref” and await a new setting.
(In the event of a controller change, 061 must be set as indicated in the instructions from Danfoss)

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User Guide | Controller for condensing unit, OptymaTM Plus

Menu survey
Function

Parameter

SW = 3.7x

Code Min. value Max. value

Factory setting

Actual setting

Normal operation

Set point (regulation reference follows the number of degrees above the outside temperature Tamb)

– – – 2.0 K

20.0 K 8.0 K

Regulation

Select SI or US display. 0=SI (bar and °C). 1=US (Psig and °F)

r05 0/°C

1/F

0/°C

Internal Main Switch. Manual and service = -1, Stop regulation = 0, Start regulation =1

r12 -1

Offset during night operation. During night operation the reference is raised by this value

r13 0 K

10 K

2 K

Set point for suction pressure Ts (only for OptymaTM Plus inverter)

r23 -30 °C 10 °C

-7 °C

Readout of reference for Tc

r29

–

Thermostat cut-in value for an external heating element (069=2 and o40=1)

r71 -30,0 °C 30,0 °C -25 °C

Min. condensing temperature (lowest permitted Tc reference)

r82 0 °C

40 °C

25 °C

Max. condensing temperature (highest permitted Tc reference)

r83 20 °C

50 °C

40 °C

Max. discharge gas temperature Td

r84 50 °C 140 °C 125 °C

Alarms

Alarm time delay on signal on the DI2 input. Active only if o37=4 or 5.

A28 0 min. 240 min. 30 min.

Alarm for insufficient cooling in condenser. Temperature difference 30.0 K = Alarm disabled

A70 3.0 K

30.0 K 10.0 K

Delay time for A80 alarm. See also parameter A70.

A71 5 min. 240 min. 30 min.

Compressor

Min. ON-time

c01 1 s

240 s

5 s

Min. OFF-time

c02 3 s

240 s

120 s

Min. time between compressor starts

c07 0 min. 30 min. 5 min.

Pump down limit at which the compressor is stopped (setting 0.0 = no function)

*** c33 0,0 bar 6,0 bar 0,0 bar

Min. compressor speed

c46 25 Hz 70 Hz 30 Hz

Start speed for compressor

c47 30 Hz 70 Hz 50 Hz

Max. compressor speed

c48 50 Hz 100 Hz 100 Hz

Max. compressor speed during night operation (%-value of c48)

c69 50%

100% 70%

Definition of compressor control mode

* c71 0

0: No compressor – Condensing unit OFF

1: Fixed speed – Input DI1 used to start / stop of fixed speed compressor

2: Variable speed – Input DI1 used for start / stop of variable speed-controlled compressor

with a 0 10 V signal on AO2

Time delay for high Td. The compressor will stop when time expires.

c72 0 min. 20 min. 1 min.

Max. pressure. Compressor stops if a higher pressure is recorded

*** c73 7,0 bar 31,0 bar 23,0 bar

Difference for max. pressure (c73)

c74 1,0 bar 10,0 bar 3,0 bar

Min. suction pressure Ps. Compressor stops if a lower pressure is recorded

*** c75 -0,3 bar 6,0 bar 1,4 bar

Difference for min. suction pressure and pump down

c76 0,1 bar 5,0 bar 0,7 bar

Amplification factor Kp for compressors PI-regulation

c82 3,0

30,0

20,0

Integration time Tn for compressors PI-regulation

c83 30 s

360 s

60 s

Liquid Injection Offset

c88 0,1 K

20,0 K 5,0 K

Liquid Injection hysterese

c89 3,0 K

30,0 K 15,0 K

Compressor stop delay after Liquid injection

c90 0 s

10 s

3 s

Desired compressor speed if the signal from the pressure transmitter Ps fails

c93 25 Hz 70 Hz 60 Hz

Min On time during Low Ambient LP

c94 0 s

120 s

0 s

Measured Tc for which the Comp min speed is raised to StartSpeed

c95 10,0 °C 70,0 °C 50,0 °C

Control parameters

Amplification factor Kp for PI-regulation Integration time Tn for PI-regulation Kp max for PI regulation when the measurement is far from reference

n04 1.0 n05 20 n95 5,0

20.0

7.0

120

50,0

20,0

Fan

Readout of fan speed in % Permitted change in fan speed (to a lower value) % per second. Jog speed (speed as a % when the fan is started)

F07 F14 1,0% F15 40%

5,0% 100%

5,0% 40%

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User Guide | Controller for condensing unit, OptymaTM Plus

continued

Code Min.

Jog speed at low temperature

F16 0%

Definition of fan control: 0=Off; 1=Internal control. 2=External speed control

F17 0

Minimum fan speed. Decreased need will stop the fan.

F18 0%

Maximum fan speed

F19 40%

Manual control of the fan’s speed. (Only when r12 is set to -1)

** F20 0%

Phase compensation (should only be changed by specially trained personnel.)

F21 0

Pre-Ventilation time on A2L-refrigerants before compressor start

F23 30

Real time clock

Time at which they switch to day operation

t17 0 hrs

Time at which they switch to night operation

t18 0 hrs

Clock – Setting of hours

t07 0 hrs

Clock – Setting of minute Clock – Setting of date

t08 0 min. t45 1 day

Clock – Setting of month

t46 1 mon.

Clock – Setting of year

t47 0 year

Miscellaneous

Network address

o03 0

On/Off switch (Service Pin message) IMPORTANT! o61 must be set prior to o04 (used at LON 485 only)

o04 0/Off

Access code (access to all settings)

o05 0

Readout of controllers software version

o08

Select signal for display view. 1=Suction pressure in degrees, Ts. 2=Condensing pressure in degrees, Ts

o17 1

Pressure transmitter working range Ps – min. value

o20 -1 bar

Pressure transmitter working range Ps- max. value

o21 6 bar

Refrigerant setting: 2=R22. 3=R134a. 13=User defined. 17=R507. 19=R404A. 20=R407C. 21=R407A. 36=R513A. 37=R407F. 40=R448A. 41=R449A. 42=R452A. 39=R1234yf. 51=R454C. 52=R455A

* o30 0

Input signal on DI2. Function: (0=not used, 1=External safety function. Regulate when closed, 2=external main switch, 3=Night operation when closed, 4=alarm function when closed, 5=alarm function when open. 6=on/off Status for monitoring. 7=Alarm from speed regulation

o37 0

Aux relay function: (0=not used, 1=External heating element, 2=liquid injection, 3=oil return function)

*** o40 0

Pressure transmitter working range Pc min. value

o47 -1 bar

Pressure transmitter working range Pc max. value

o48 6 bar

Setting of condensing unit type (is factory set when the controller is mounted and cannot be * o61 0 subsequently changed)

The sensor input S3 is to be used to measure the discharge gas temperature (1=yes)

o63 0

Replace the controllers factory settings with the present settings

o67 Off (0)

Defines the use of the Taux sensor: 0=not used; 1=measuring of oil temperature; 2=measurement from external heat function 3=other optional use

o69 0

Period time for heating element in crankcase (ON + OFF period) Difference for heating elements 100% ON point Difference for heating elements 100% OFF point Read-out of operating time for condenser unit. (Value must be multiplied by 1,000). The value can be adjusted. Read-out of compressor operating time. (Value must be multiplied by 1,000). The value can be adjusted. Read-out of operating time of heating element in crankcase. (Value must be multiplied by 1,000). The value can be adjusted. Read-out of number of HP alarms. The value can be adjusted. Read-out of number of LP alarms. The value can be adjusted. Read-out of number of Td alarms. The value can be adjusted. Read-out of number of blocked condenser alarms. The value can be adjusted Oil return management. Compressor speed for the counter starting point

P45 30 s P46 -20 K P47 5 K P48 –
P49 –
P50 –
P51 P52 P53 P90 P77 25 Hz

Max.
40% 2 40% 100% 100% 50 180

Fac.
10% 1 10% 100% 0% 20 30

23 hrs 0 23 hrs 0 23 hrs 0 59 min. 0 31 days 1 12 mon. 1 99 years 0

240 1/On

0 0/Off

100

5 bar

-1

200 bar 12

5 bar 200 bar 77

0 bar 32 bar 0

1 On (1) 3

1 Off (0) 0

255 s -5 K 20 K –
–
–
70 Hz

240 s -10 K 10 K 0 h
0 h
0 h
0 0 0 0 40 Hz

Actual

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User Guide | Controller for condensing unit, OptymaTM Plus

continued
Oil return management. Limit value for counter Oil return management. Boost-speed Oil return management. Boost-time. Service Readout pressure on Pc Readout temperature Taux Status on DI1 input. 1=on=closed Status on night operation (on or off ) 1=on=night operation Readout superheat Readout temperature at S6 sensor Status on DI2 input. 1=on=closed Readout the compressor capacity in % Status on relay to compressor. 1=on=closed Status on relay to fan. 1=on=closed Status on relay to alarm. 1=on=closed Status on relay “Aux”. 1=on=closed Status on relay to heating element in crank case. 1=on=closed Status on high voltage input DI3. 1=on=230 V Readout condensing pressure in temperature Readout pressure Ps Readout suction pressure in temperature Readout ambient temperature Tamb Readout discharge temperature Td Readout suction gas temperature Ts Readout the voltage on the output AO1 Readout the voltage on the output AO2
*) Can only be set when regulation is stopped (r12=0) **) Can be controlled manually, but only when r12=-1 ***) This parameter depends on parameter o30 and o61 settings
Factory setting If you need to return to the factory-set values, it can be done in this way: – Cut out the supply voltage to the controller – Keep upper and lower button depressed at the same time as you reconnect the supply voltage

Code Min.
P78 5 min. P79 40 Hz P80 10 s

Max.

Fac.

720 min. 100 Hz 600 s

20 min. 50 Hz 60 s

Actual

u01 bar u03 °C u10 u13 u21 K u36 °C u37 u52 % ** u58 ** u59 ** u62 ** u63 ** u71 u87 U22 °C U23 bar U24 °C U25 °C U26 °C U27 °C U44 V U56 V

Reset of unit statistics parameters All the Unit status parameters (P48 to P53 and P90) can be set / cleared using the following procedure · Set Main Switch to 0 · Change the Statistics parameters – like setting Alarm counters to 0 · Wait 10 seconds – to ensure write to EEROM · Make a repower of the Controller – transfer new settings to “statistics function” · Set Main Switch ON – and the parameters is set to the new value

BC172686425380en-001101 | 15

User Guide | Controller for condensing unit, OptymaTM Plus
Connections

R=120 0 10 V 0 10 V
R=120

AKS32R AKS32R

– +- +

24 25 26 27 DI1 DI2

28 29 30 31 32 33

34 35 36 373839 S2 S3 S4

40 41 42 43 S5 S6

EKA Display

51 52 53 54 55 56 57 60 61 62
RS AO1 AO2 MODBUS 485

FAN
LN 1 23 4 56

Alarm Comp CCH Fan Aux 7 8 9 10 11 12 13 14 15 16 17 18 19

230 V

230 V 230 V 230 V 230 V 230 V

DI3 22 23
LP HP
230 V

DI1 Digital input signal. Used to start/stop cooling (room thermostat) Starts when the input is short-circuited.
DI2 Digital input signal. The defined function is active when the input is short-circuited/ opened. The function is defined in o37.
Pc Pressure transmitter, ratiometric AKS 32R, 0 to 32 bar Connect to terminal 28, 29 and 30.
Ps Pressure transmitter, ratiometric e.g. AKS 32R, -1 to 12 bar Connected to terminal 31, 32 and 33.
S2 Air sensor, Tamb. Pt 1000 ohm sensor, eg. AKS 11
S3 Discharge gas sensor, Td. Pt 1000 ohm sensor, eg. AKS 21
S4 Suction gas temperature, Ts. Pt 1000 ohm sensor, eg. AKS 11
S5, Extra temperature measurement, Taux. Pt 1000 ohm sensor, eg. AKS 11
S6, Extra temperature measurement, S6. Pt 1000 ohm sensor, eg. AKS 11
EKA Display If there is be external reading/operation of the controller, display type EKA 163B or EKA 164B can be connected.
RS485 (terminal 51, 52,53) For data communication, but only if a data communication module is inserted in the controller. The module can be Lon. If data communication is used, it is important that the installation of the data communication cable is performed correctly. See separate literature No. RC8AC…

AO1, terminal 54, 55 Output signal, 0 10 V. Must be used if the fan is equipped with internal speed control and 0 10 V DC input, e.g. EC-motor.
AO2, terminal 56, 57 Output signal, 0 10 V. Must be used if the compressor is speed controlled.
MODBUS (terminal 60, 61, 62) Built in Modbus data communication. If data communication is used, it is important that the installation of the data communication cable is performed correctly. See separate literature No. RC8AC… (Alternatively the terminals can be connected to an external display type EKA 163A or 164A, but then they cannot be used for data communication. Any data communication must then be carried out by one of the other methods.)
Supply voltage 230 V AC (This must be the same phase for all 230 V connections).
FAN Fan connection. Speed controlled internally.
Alarm There is a connection between terminal 7 and 8 in alarm situations and when the controller is without power.
Comp Compressor. There is a connection between terminal 10 and 11, when the compressor is running.
CCH Heating element in the crankcase There is connection between terminals 12 and 14 when heating takes place.
Fan There is connection between terminals 15 and 16 when the fan’s speed is raised to over 95%. (Fan signal changes from terminal 5-6 to 15-16. Connect wire from terminal 16 to the fan.)

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User Guide | Controller for condensing unit, OptymaTM Plus

Aux Liquid injection in suction line / external heating element / oil return function for speed-controlled compressor There is connection between terminals 17 and 19, when the function is active.
DI3 Digital input signal from low/high pressure monitoring. The signal must have a voltage of 0 / 230 V AC.
Electric noise Cables for sensors, DI inputs and data communication must be kept separate from other electric cables: – Use separate cable trays – Keep a distance between cables of at least 10 cm. – Long cables at the DI input should be avoided

Installation considerations
Accidental damage, poor installation, or site conditions, can give rise to malfunctions of the control system, and ultimately lead to a plant breakdown. Every possible safeguard is incorporated into our products to prevent this. However, a wrong installation, for example, could still present problems. Electronic controls are no substitute for normal, good engineering practice. Danfoss will not be responsible for any goods, or plant components, damaged as a result of the above defects. It is the installer’s responsibility to check the installation thoroughly, and to fit the necessary safety devices. Special reference is made to the necessity of signals to the controller when the compressor is stopped and to the need of liquid receivers before the compressors. Your local Danfoss agent will be pleased to assist with further advice, etc.

Data

Supply voltage 230 V AC +10/-15 %. 5 VA, 50 / 60 Hz

Sensor S2, S3, S4, S5, S6

Pt 1000

180

61.5

Measuring range

-60 120 °C (S3 to 150 °C)

109

Accuracy

Controller

±1 K below -35°C ± 0.5 K between -35 25 °C; ±1 K above 25 °C

Pt 1000 sensor

±0.3 K at 0 °C ±0.005 K per degree

Measuring of Pc, Ps

Pressure transmitter

Ratiometric. eg. AKS 32R, DST-P110

Display

LED, 3-digits

External display
Digital inputs DI1, DI2
Digital input DI3

EKA 163B or 164B (any EKA 163A or 164A)
Signal from contact functions Requirements to contacts: Gold plating Cable length must be max. 15 m Use auxiliary relays when the cable is longer
230 V AC from safety pressostat. Low/high pressure

Electrical connection cable
Triac output

Max.1.5 mm2 multi-core cable

Fan

Max. 240 V AC, Min. 28 V AC Max. 2.0 A

Leak < 1 mA

CE (250 V AC)

Relays*

Comp, CCH

4 (3) A

Alarm, Fan, Aux 4 (3) A

Analog output Environments

2 pcs. 0 10 V DC (For external speed control of fans and compressors) Min. load = 10 K ohm. (Max. 1 mA)
-25 55 °C, During operations -40 70 °C, During transport
20 – 80% Rh, not condensed
No shock influence / vibrations

Density

IP 20

Mounting

DIN-rail or wall

Weight
Data communication
Power reserve for the clock

0.4 kg Fixed Extension options
4 hours

MODBUS LON

Approvals

EC Low Voltage Directive and EMC demands re CEmarking complied with LVD tested acc. EN 60730-1 and EN 60730-2-9, A1, A2 EMC-tested acc. EN 61000-6-2 and EN 61000-6-3

* Comp and CCH are 16 A relays. Alarm and Fan are 8 A relays. Max. load must be observed

BC172686425380en-001101 | 17

Ordering
Type OptymaTM Plus Plug EKA 175 EKA 163B EKA 164B EKA 163A EKA 164A Wire with plug EKA 183A

Function Condensing unit controller Prepared for data communication Plug for screw terminals not enclosed Plug with screw terminals Data communication module LON RS485
External display with plug for direct connection
External display with operation buttons and plug for direct connections
External display with screw terminals
External display with operation buttons and screw terminals
Wire for display unit (9 m, with plug)
Programming key

Code no. 084B8080 084B8166 084B8579 084B8574 084B8575 084B8562 084B8563 084B7630 (24 pcs.) 084B8582

BC172686425380en-001101 | 18

Documents / Resources

Danfoss Optyma Plus Controller for Condensing Unit [pdf] User Guide
Optyma Plus Controller for Condensing Unit, Controller for Condensing Unit, Condensing Unit

References

User Manual

Danfoss Optyma Plus Controller for Condensing Unit User Guide

Optyma Plus Controller for Condensing Unit

Specifications:

Product Usage Instructions:

1. Condensing Unit Control:

2. Fan Operation:

3. Liquid Injection:

4. Low Pressure Monitoring:

5. Pump Down Limit:

6. Separate Thermostat Function:

7. Digital Inputs:

Frequently Asked Questions (FAQ):

Q: How can I adjust the fan speed at startup?

Q: What happens if the compressor detects low suction
pressure?

Documents / Resources

References

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