Daikin Installation and Maintenance Manual: MicroTech Unit Controller Options – Field-Installation Wiring

Introduction

Field Control Wiring

Daikin Applied Rooftop and Self Contained units are available with various control arrangements that may require low voltage field wiring. Detailed descriptions of these options are found in IM 919, "MicroTech® Unit Controller for Commercial Rooftop Systems, Applied Rooftop Systems and Self-Contained Air Conditioners." Refer to the unit wiring diagrams for installation information. All wiring must comply with applicable codes and ordinances. Failure to adhere to these specifications will void the warranty.

This equipment must be installed by qualified personnel experienced with this type of equipment and familiar with local codes and regulations. Carefully read all instructions and consider any special requirements before installation. Provide this manual to the owner and explain its contents.

Unit Nameplate

The unit nameplate, located on the interior and exterior of the main controls, displays the unit model number, serial number, performance data, and electrical characteristics.

Important Message to the Owner

Read these instructions carefully and keep them near the product for future reference. While primarily for installers, this manual also contains useful maintenance information. Ensure the installer explains the product's operation and periodic maintenance requirements.

Recognize Safety Symbols, Words, and Labels

It is the responsibility of the owner and installer to read and comply with all safety information, instructions, and hazard identification symbols. Non-compliance increases the risk of property damage, product damage, serious personal injury, or death. Improper installation, operation, or maintenance can void the warranty.

Hazardous Information Messages

The following symbols and labels are used to indicate immediate or potential hazards:

• CAUTION: Indicates potentially hazardous situations that could result in personal injury or equipment damage if not avoided.
• WARNING: Indicates potentially hazardous situations that could result in property damage, severe personal injury, or death if not avoided.
• DANGER: Indicates a hazardous situation that will result in death or serious injury if not avoided.
• NOTICE: Provides important information concerning a process, procedure, special handling, or equipment attributes.

Agency Listed

The unit is agency listed by Intertek (C-US).

Installation

RDT, RFS and RPS, Units

DANGER: Electrical shock hazard. Can cause severe injury or death. Connect only low voltage NEC Class II circuits to terminal blocks TB2 and TB5. Reinstall and secure all protective deadfront panels after wiring is complete.

All field control wiring connections are made at the Class II terminal block TB2, located in the main control panel. Field wiring for the 115-volt receptacle and lights connects to terminal block TB7, also in the main control panel. Refer to Figure 1 and Figure 2. Two 7/8" knockouts are provided for wire entry.

Figure 1 Description: Illustrates field wiring connections for RDT, RFS, and RPS units, showing a main control panel with a 24V field terminal block (TB2) and a control wiring raceway cover providing access to harnesses for unit-mounted control devices.

Figure 2 Description: Depicts a control wiring raceway with three 7/8" knockouts for wire entry, noting that the field may need to cut larger holes as required.

RCS/RFS Units

DANGER: Electrical shock hazard. Can cause severe injury or death. Connect only low voltage NEC Class II circuits to terminal blocks TB2 and TB5. Reinstall and secure all protective deadfront panels after wiring is complete.

The RCS unit receives 115V and 24V control circuit power, along with control signals, from the RFS unit. Two 7/8" knockouts are provided on the right side of the RCS control box. Interconnecting wiring enters the RFS unit through 7/8" knockouts in the bottom of the main control panel. This wiring connects to TB4 in the RFS unit and TB5 in the RCS unit. Refer to Figure 4. A 7/8" knockout is also available at the end of the unit base, as shown in Figure 3.

Figure 3 Description: Shows wiring connections for RCS 050D through 140D units, featuring an externally operated disconnect switch and 7/8" knockouts for field control wiring.

Figure 4 Description: Illustrates the interconnecting control wiring between RCS and RFS units. It shows connections to the main control panel, RFS Unit (with Condenser control panel and TB4), and RCS Unit (with TB5), indicating key terminals like 24V, 115V, PB4/DS4P, DS2, and PB1/DS1.

MicroTech® Controller

WARNING: All field wiring must be powered using unit transformers. Do not ground the transformer for a field signal to chassis ground; use the same ground as the controller to prevent a voltage potential above 3V, which can damage the MicroTech Unit Controller. If the unit transformer is not used, dry contacts must be isolated with an isolation (RIB) relay.

Inputs to MicroTech Unit Controller

• Zone Sensor:
  • Analog Sensor with tenant override
  • Analog Sensor with tenant override & set point adjustment
  • Digital Sensor with tenant override & Setpoint adjustment
• Humidity Sensor
• External Signal
• External Outdoor Air Damper Reset
• External Time Clock
• Emergency Shutdown
• CO2
• Outdoor Air Flow Station

Outputs from MicroTech Unit Controller

• Remote Alarm Output
• Fan Operation Signal
• Outdoor Damper for SCU only
• Pump Signal SCU only

Analog Sensor with Tenant Override and No Set Point Adjustment

On all unit styles (DPS/MPS/RTU/SCU), the analog zone/space sensor is a 10K ohm thermistor with a tenant override feature. It is wired to terminals 120 and 121 on the terminal block 2 (TB2). A shielded wire must be installed to the ground terminal (typically 132G on terminal block 2). Refer to Figure 5 for wiring details.

Figure 5 Description: A wiring diagram showing connections for an Analog Sensor with Tenant Override and No Set Point Adjustment. It illustrates wiring from a WALLSTAT (OVERRIDE, C, ZNT1 ZONE SENSOR) to Unit Terminal Block TB2 (terminals 120, 121, 132G), indicating a 10k thermistor and a tenant override button.

Analog Sensor with Tenant Override and Set Point Adjustment

On all unit styles (DPS/MPS/RTU/SCU), the analog zone/space sensor is a 10K ohm thermistor with a tenant override and manual cooling/heating set point adjustment feature. The sensor is wired from terminal S to TB2 (120), C to TB2 (121), and P to TB2 (132). A shielded wire needs to be installed to the ground terminal (typically 132G on terminal block 2). Review Figure 6 for wiring connection details.

Figure 6 Description: A wiring diagram for an Analog Sensor with Tenant Override and Set Point Adjustment. It shows wiring from a Wall Sensor (Set Point Adjustment P, 10k Thermistor S, Tenant Override Button C) to the Unit Control Panel TB2 (terminals 132, 120, 121), indicating V+, GND, SEN1, SET1.

Figure 7 Description: Components of an Analog Sensor, showing the Setpoint Adjustment dial and the Tenant Override button.

Digital Sensor with Tenant Override and Set Point Adjustment

On all unit styles (DPS/MPS/RTU/SCU):

WARNING: It is crucial to have 24VAC power from TB(2) terminal 101 only, not from any field-installed transformer.

The digital zone/space sensor is wired to field terminal block 2 (TB2) terminals 101, 120, 121, and 132. Pressing the tenant override button will not change the occupancy symbol status on the sensor, and there is no feedback from the MicroTech unit controller for occupancy to this sensor. Calibration through the MicroTech unit controller is necessary under "Commission unit" | "Htg/Clg Chag Ovr Set-Up" | "CalDRemSpt" @ 50F and 86F. Review Figure 8 for wiring connection details.

Figure 8 Description: A wiring diagram for a Digital Sensor with Tenant Override and Set Point Adjustment. It shows wiring from a Wall Sensor (Set Point Adjustment, 10k Thermistor, Tenant Override Button) to the Unit Control Panel TB2 (terminals 132, 120, 121, 101), indicating V+, GND, SEN1, SET1.

Figure 9 Description: Components of a Digital Sensor, showing Occupancy Status indicator and the Tenant Override button.

Humidity Sensor

WARNING: This sensor cannot be used as an analog space sensor as it does not contain a 10K thermistor.

Ensure the internal J1 jumper in the humidity sensor is set to the 0-10 VDC position for proper controller function. Either a wall mount or duct mount humidity sensor is available. The sensor must be wired to terminals 126, 127, and 131 on the unit field terminal block (TB2). Terminal 126 connects to OUT, terminal 127 to COM, and terminal 131 to IN on the humidity sensor. These terminals are factory wired to the Expansion Board A AIX6. The sensor can output 0-10VDC for 0% to 100% RH values, which are adjustable via the Dehum Setup menu in the Commission Unit section.

Figure 10 Description: Components of a Humidity Sensor, showing the RH Output Jumper, TB2 Terminal Block (Not Used), and TB1 Terminal Block.

Figure 11 Description: Wiring diagram for a Humidity Sensor, DPS Only, showing connections to TB2 (SHS1, NB, 219C, 226A, 227A) and Humidity Sensor terminals (OUT, COM, IN).

Figure 12 Description: Wiring diagram for a Humidity Sensor, MPS Only, showing connections to TB2 (SHS1, NB, 24VDCO-, 226A, 227A) and Humidity Sensor terminals (OUT, COM, IN).

Figure 13 Description: Wiring diagram for a Humidity Sensor, RPS and SCU, showing connections to TB2 (241B-4, T5-X6, 245C-4, 247C-2, 126, 127, 127G, 131) and Humidity Sensor terminals (OUT, COM, IN).

External Time Clock

An external time clock or tenant override switch can be used by installing a set of dry contacts across terminals 101 and 102 on the field terminal block (TB2). When these contacts close, 24 VAC is applied to binary input MCB-DI3, placing the unit into occupied mode. When the contacts open, the unit operates according to the controller's internal or network schedule. The ON-AUTO switch (S7) is a manual occupancy switch that bypasses the time clock or tenant override and can be mounted remotely. If S7 is present with an external time clock, it must be set to AUTO.

Figure 14 Description: Wiring diagram for an External Time Clock, showing connections for DPS and MPS units to TB2 terminals 101, 102, and 211A (ODI3).

Figure 15 Description: Wiring diagram for an External Time Clock, showing connections for RPS and SCU units to TB2 terminals 101, 102, 213, 214, 215, 216, 217. Includes notes regarding internal timeclock software and terminal jumpering.

NOTE: All field wiring must be powered using unit transformers. Do not ground the transformer for a field signal to chassis ground; use the same ground as the controller to prevent a voltage potential above 3V, which can damage the MicroTech Unit Controller. If the unit transformer is not used, dry contacts must be isolated with an isolation relay.

External Outdoor Air Damper Minimum Position Reset

This function requires a field-supplied reset signal in the range of 0-10 VDC or 0-20 mA, wired to terminals 124 and 125 on the field terminal block (TB2). Options include an OA flow station, CO2 sensor, or a field-generated 0-10vDC/0-20mA signal. The min/max signal can be user-defined via the MicroTech unit controller. Default settings are 0vDC or mA for minimum and 10vDC or 20mA for maximum. MicroTech unit controller setup is required for this setpoint; refer to OM 920 for details on commissioning, minimum outdoor air setup, and outdoor air reset. Refer to unit wiring diagrams for termination details.

Figure 16 Description: A wiring diagram for External Outdoor Air Damper Minimum Position Reset, showing connections to TB2 terminals 124 and 125 for "REMOTE ECONO. MIN. POSITION OR EXTERNAL CO2 MIN. CONTROL", with indicated connections like 209A, 229C-6, 235D-5.

Immediate Emergency Shutdown – Smoke

Terminals 105 & 106 on TB2 can be used for any field-supplied component requiring a unit emergency shutdown. When these terminals are used, the factory-installed jumper must be removed. Emergency shutdown faults can be configured to automatically clear once the condition causing the alarm is corrected by navigating to "Commission Unit" | "Alarm Configuration" | "Emerg Stop" and changing the default "No" value to "Yes." Check building codes to verify compliance with fire safety regulations.

Figure 17 Description: A wiring diagram for Immediate Emergency Shutdown, Smoke, showing connections for DPS and MPS units to TB2 terminals 103, 104, 105, 106 for RA Smoke Detector, SA Smoke Detector, and FIELD EMERGENCY OFF.

Figure 18 Description: A wiring diagram for Immediate Emergency Shutdown, Smoke, showing connections for RPS and SCU units to TB2 terminals 104, 105, 106 for FIELD SMOKE and FIELD EMERGENCY OFF.

Ventilation Override (Smoke Purge) DPS Only

The MicroTech Unit Controller can perform a ventilation override via Modbus if terminals Din2 and GND at Terminal strip 3 on the ECM are made. Install an isolation relay to make a dry NO contact across the return/exhaust fan Din2 and GND. In a smoke situation, a field-wired smoke detector can issue a 24VAC signal to the DI4 terminal at the MicroTech controller, triggering an emergency fault. The unit will shut down. The field must configure the NO contact to close upon a smoke shutdown to allow the return/exhaust fan to run. Setting the speed of the drive during ventilation override is described below.

Setting the RF/EF max vent speed:

1. After entering the controller password 6363, click on "Commission Unit".
2. Scroll down and click on "RF/EF Set-Up".
3. Scroll down to "MaxVentSpd" and select the desired speed for the ECM during a smoke shutdown.

Figure 19 Description: Illustrates Ventilation Override, showing terminal strips and connections for Din2, Din3/GND/02/20v, Ain2/Aout, and a "Normally Open Dry Contact" connection.

CO2 Sensor or Outdoor Air Damper Flow Station Only

On all unit styles (MPS/DPS/RTU/SCU), the CO2 sensor or outdoor air damper flow station must be wired to terminals X1 and M at the MicroTech Unit Controller. Terminal M serves as the common for all analog inputs. Ensure correct field wiring polarity to read a valid PPM value.

WARNING: The CO2 sensor (and all field-installed devices) must be powered from the same transformer as the controller to prevent damage to the controller.

A table details Universal Inputs/Outputs for CO2/Min OA/OA CFM, with signal types of 0-10VDC or 4-20 mA.

Outdoor Air Damper Flow Station and CO2 Reset Setup

Procedure:

1. At the MicroTech Unit controller, enter password 6363.
2. Scroll down to "Unit Configuration" and select it.
3. Scroll down to "OA Flow Stn" and select "6" for "FS/Rst".
4. Scroll up to "Apply Changes" and select "yes" to restart the controller.
5. Enter password 6363, scroll down to "Commission unit" and select it.
6. Scroll down to the "Min OA setup" menu and select it.
7. Scroll down to Min OA reset and select "IAQ VDC" or "IAQ mA" depending on the sensor type installed.
8. Scroll up to "Apply Changes" and select "yes" to restart the controller.

CO2 Sensor Wiring

On all style units (MPS/DPS/RTU/SCU), the CO2 sensor needs to be wired to terminals X1 and M at the MicroTech unit Controller. Terminal M is the common for all analog inputs. Ensure correct field wiring polarity to read a valid PPM value.

EBTRON or Field Outdoor Air Damper Flow Station Wiring

Wiring configurations for various expansion modules and unit types are provided:

• MPS (17-50 Tons)/DPS Expansion Module B: Connects to terminals X2, X3, X4, X5 for inputs like Reheat #1, Gas Heat LS2 Switch, OA Flow, FSG Alarm Input (FSG-3), Supply Temp Leaving Wheel, Exhaust Temp Leaving Wheel. Signal types include 0-10 VDC, Dry Contact, 0-10 VDC or 4-20 mA, and 10K Thermistor (STD).
• DPS (15 Tons) with EV Type = 3, 4, 5 or 6 Expansion Module D: Connects to terminals X9, X10, X11 for inputs like Supply Temp Leaving Wheel, Exhaust Temp Leaving Wheel, OA Flow. Signal types include 0-10 VDC, Dry Contact, 0-10 VDC or 4-20 mA, and 10K Thermistor (STD).
• RTU/SCU/MPS (62-70 Tons) Expansion Module E: Connects to terminals X1, X2 for OA Flow. Signal type is 0-10 VDC or 4-20 mA.

For Maverick (MPS) and Rebel (DPS 3–12 ton) units, wire the outdoor air damper flow station to terminals X3 and M on expansion module B. For Rebel DPS (15 ton) units, confirm EV (Expansion Valve) type in unit configuration at the MicroTech controller. If EV type is 3, 4, 5, or 6, wire the outdoor air damper flow station to terminals X11 and M on expansion module D. For Rooftop (RTU) and Self Contained (SCU) units, wire the outdoor air damper flow station to terminals X1 and M on expansion module E. Terminal M is common for all analog inputs; ensure correct polarity for a valid CFM value.

Outputs from the MicroTech Unit Controller

Remote Alarm Output

The digital alarm output (MCB-DO9) indicates the alarm group with the highest priority active alarm. It is ON when no alarms are active. Configuration options for alarm actions include ON, Fast Blink, Slow Blink, or OFF, accessible via the "Alarm Out Config" menu in the Extended menus. The Remote Alarm Output supplies 24 VAC to terminal 115 on the field terminal block (TB2) when ON. To use this signal, wire the coil of a field-supplied 24 VAC pilot relay across terminals 115 and 117 on TB2. The T3 control transformer supplies the 24 VAC through the output relay to energize the field relay. Refer to as-built wiring diagrams.

Figure 20 Description: A wiring diagram for the Remote Alarm Output, showing connections for DIGITAL OUTPUTS DO9 (EXT. ALARM SIGNAL) to TB2 terminals 115 and 117.

Fan Operation Output

The Fan Operation Output supplies 24 VAC to terminal 116 on the field terminal block (TB2) when the supply fan output is ON. To use this signal, wire the coil of a field-supplied 24 VAC pilot relay across terminals 116 and 117 on TB2. The T3 control transformer supplies the 24 VAC through the output relay to energize the field relay.

Figure 21 Description: A wiring diagram for the Fan Operation Output, showing connections for DIGITAL OUTPUT DO10 (FAN OPERATION) to TB2 terminals 116 and 117.

Outdoor Damper (Self-Contained Unit Only)

The Outdoor Damper Output supplies 24 VAC to terminal 119 on the field terminal block (TB2) when the output is ON. To use this signal, wire the coil of a field-supplied 24 VAC pilot relay across terminals 119 and 117 on TB2. The T3 control transformer supplies the 24 VAC through the output relay to energize the field relay.

Figure 22 Description: A wiring diagram for the Outdoor Damper Output, showing connections for DIGITAL OUTPUT DO7 (OUTDOOR DAMPER) to TB2 terminals 119 and 117.

Pump Signal Output (Self-Contained Unit Only)

When applicable, the Pump Signal Output supplies 24 VAC to terminal 113 on the field terminal block (TB2) when the output is ON. To use this signal, wire the coil of a field-supplied 24 VAC pilot relay across terminals 113 and 117 on TB2. The T3 control transformer supplies the 24 VAC through the output relay to energize the field relay. Refer to as-built wiring diagrams.

Figure 23 Description: A wiring diagram for the Pump Signal Output, showing connections for DIGITAL OUTPUT DO8 (PUMP SIGNAL) to TB2 terminals 118 and 117.

NOTES TO FIELD: All field-mounted relays shall have separate NEC Class II, 24VAC circuits. The total VA of the field-mounted relays cannot exceed 15 VA.

Daikin Applied Training and Development

To enhance the care and efficiency of your Daikin Applied equipment, training is highly recommended. For information on all Daikin Applied HVAC products, visit www.DaikinApplied.com and click on Training, or call 540-248-9646 and ask for the Training Department.

Warranty

All Daikin Applied equipment is sold under its standard terms and conditions of sale, including a Limited Product Warranty. Consult your local Daikin Applied Representative for warranty details. You can find your local representative at www.DaikinApplied.com.

Aftermarket Services

To locate your nearest parts office, visit www.DaikinApplied.com or call 800-37PARTS (800-377-2787). To find your local service office, visit www.DaikinApplied.com or call 800-432-1342.

This document contains the most current product information as of this printing. For the most up-to-date product information, please visit www.DaikinApplied.com.

Products are manufactured in an ISO Certified Facility.