AAON WHSP-454 Controller Module Installation Guide

AAON WHSP-454 Controller Module

OVER VIEW

Features
The WSHP-454 Module monitors the compressors on an AAON® Water Source Heat Pump unit and can disable the compressors based on low Suction Pressure, Leaving Water Temperature, and Water Proof of Flow inputs. It also utilizes a Delay Timer to prevent the compressors from turning on at the same time. The WSHP-454 Module’s water circuit configuration can be either single or dual. There are nine glycol configurations for the WSHP- 454 Module—0%-40% in increments of 5%. The glycol will automatically default to 0%. The WSHP-454 Module can be used stand-alone. The WSHP-454 Module requires a 24 VAC power connection with an appropriate VA rating.

Features of the WSHP-454 include:

• Monitoring suction pressure, leaving water temperature, and water proof of flow.
• Provides a delay timer to prevent compressors from turning on at the same time.
• Contains a 2×8 LCD character display and 4 buttons that allow for status display, setpoint changes, and configuration changes.

Note: The WSHP-454 Module contains no user-serviceable parts. Contact qualified technical personnel if your module is not operating correctly.

 

INSTALLATION & WIRING

Environmental Requirements

• The WSHP-454 Module needs to be installed in an environment that can maintain a temperature range between -30°F and 150°F and not exceed 90% RH levels (non-condensing).

Mounting

• The WSHP-454 Module is housed in a plastic enclosure. It is designed to be mounted by using the 3 mounting holes in the enclosure base. It is important to mount the module in a location that is free from extreme high or low temperatures, moisture, dust, and dirt. Be careful not to damage the electronic components when mounting the module. See Figure 1 for Module dimensions (in inches).

Power Supply

• The WSHP-454 Module requires a 24 VAC power connection with an appropriate VA rating.

WARNING: Observe polarity! All boards must be wired GND-to-GND and 24 VAC-to-VAC. Failure to observe polarity could result in

Important Wiring Considerations
Please read carefully and apply the following information when wiring the WSHP-454 Module:

1. To operate the WSHP-454 Module in Stand-Alone mode, you must connect power to the 24 VAC input terminal block. Do not allow wire strands to stick out and touch adjoining terminals. This could potentially cause a short circuit.
2. All 24 VAC wiring must be connected so that all ground wires remain common. Failure to follow this procedure can result in damage to the module and connected devices.
3. All wiring is to be in accordance with local and national electrical codes and specifications.
4. Check all wiring leads at the terminal block for tightness. Be sure that wire strands do not stick out and touch adjacent terminals. Confirm that all transducers required for your system are mounted in the appropriate location and wired into the correct terminals.

Stand-Alone Wiring Single Water Circuit

• To operate the WSHP-454 Module as a stand-alone, connect the Module to a 24 VAC power connection with an appropriate VA rating. See Figure 2 for wiring.

Stand-Alone Wiring Dual Water Circuit

• To operate the WSHP-454 Module as a stand-alone, connect the Module to a 24 VAC power connection with an appropriate VA rating. See Figure 3 for wiring.

Sequence of Operation

General
The following inputs and outputs are available on the WSHP-454
Module. See Table 1 below to reference the Input/Output Map.

Binary Inputs
1	Compressor A1 Enable (BIN 1)
2	Compressor A2 Enable (BIN 2)
3	Compressor B1 Enable (BIN 3)
4	Compressor B2 Enable (BIN 4)
5	Reversing Valve Enable (BIN 5)
6	Water Proof of Flow System A (BIN 6)
7	Water Proof of Flow System B (BIN 7)
Analog Inputs
1	Suction Pressure A1 (Pres 1)
2	Suction Pressure A2 (Pres 2)
3	Suction Pressure B1 (Pres 3)
4	Suction Pressure B2 (Pres 4)
5	Leaving Water Temperature System A (T1)
6	Leaving Water Temperature System B (T2)
Analog Outputs
1	AOUT1*
2	AOUT2*
3	AOUT3*
4	AOUT4*
Note: Analog outputs are not usd on Stand Alone Applications
Analog Inputs
1	Compressor A1 Enable Output (RLY1)
2	Compressor A2 Enable Output (RLY2)
3	Compressor B1 Enable Output (RLY3)
4	Compressor B2 Enable Output (RLY4)
5	Alarm Output (RLY5)

Table 1: WSHP-454 Module Inputs & Outputs

• The WSHP-454 Module setpoints are preset at AAON and are based on the unit’s design as well as the type of coolant being used in the water loop. See Table 2, below & Table 3, page 11 for default settings. Note: These are default settings only. The setpoints may be different based on the unit’s design and coolant being used.

Water-Only Default Setpoints
Description	R454B
UNSAFE SUCTION	39 PSIG
LOW SUCTION HEAT MODE	96 PSIG
LOW SUCTION COOL MODE	81 PSIG
LOW LEAVING WATER TEMP	37ºF

Glycol Default Setpoints
Description	R454B 0% Glycol	R454B 5% Glycol	R454B 10% Glycol	R454B 15% Glycol	R454B 20% Glycol	R454B 25% Glycol	R454B 30% Glycol	R454B 35% Glycol	R454B 40% Glycol
UNSAFE SUCTION	39 PSIG	39 PSIG	39 PSIG	39 PSIG	39 PSIG	39 PSIG	39 PSIG	39 PSIG	39 PSIG
LOW SUCTION HEAT MODE	96 PSIG	89 PSIG	83 PSIG	78 PSIG	71 PSIG	62 PSIG	55 PSIG	47 PSIG	43 PSIG
LOW SUCTION COOL MODE	81 PSIG	81 PSIG	81 PSIG	81 PSIG	81 PSIG	81 PSIG	81 PSIG	81 PSIG	81 PSIG
LOW LEAVING WATER TEMP	37ºF	34ºF	30ºF	27ºF	20ºF	15ºF	9ºF	2ºF	0ºF

Table 3: Factory-Set Default Setpoints – Glycol

Stand-Alone Input Commands

Compressor On/Off

• A 24-volt signal to Binary Inputs #1-4 initiates each Compressor’s On function. The source for this signal would typically come from Y1 to Y4 calls from the thermostat.

Reversing Valve Enable On/Off

• A 24 volt signal on this input indicates the unit is in the Cooling Mode. Typically, the source for this signal is the “O” call from the thermostat.

Waterproof of Flow System On/Off

• A 24-volt signal to Binary Inputs #6-7 indicates Water Proof of Flow for each system.

Suction Pressure Analog Inputs

• Sensors from Analog Inputs #1-4 correlate with the Suction Pressure of each Compressor (250 PSI).

Leaving Water Temperature Thermistor Inputs

• T1 correlates with Compressors A1 & A2 (RLY1 and RLY2). T2 correlates with Compressors B1 & B2 (RLY3 and RLY4).

NOTE: When the term “ON” is used, it means there is 24 VAC on the appropriate Binary Input. When the term “OFF” is used, it means there is 0 VAC on the appropriate Binary Input.

Compressor Operation (Heat/Cool)
A compressor can energize if the following is true:

1. There is 24 VAC applied to the appropriate Binary Input for the Compressor.
2. If two compressors are enabled simultaneously, a 5 second staging delay will occur.
3. Suction Pressure is above the Low Suction Pressure Cooling (Heating) Setpoint.
4. Proof of Flow for the appropriate water loop is made
5. Leaving Water Temp is above the leaving Water Safety Setpoint (Heating Only).
6. A minimum of 3 minutes of time is met for the compressors.

Note: If the WSHP-454 Module receives a signal on the Reversing Valve Enable input, it will operate using the Cooling Mode Setpoints.

LCD Display Screen & Navigation Keys
The WSHP-454 Controller allows you to make configuration changes, view status, change setpoints, create force modes, and perform diagnostics using the keypad next to the LCD display. See Figure 4 and refer to Figure 5 for descriptions.

Figure 4: LCD Display and Navigation Keys

Main Screens Map

• Refer to the following map when navigating through the LCD Main Screens. The first screen is the address screen. To scroll through the rest of the screens, press the <MENU> button.
• Press to scroll through WSHP Screens.
• Press to go to ALARM Screens.
• Press to scroll through ALARMS Screens.
• Press to scroll through STATUS SYSTEM A Screens.
  
• Press to scroll through SETPOINT Screens.
• Press to go to STATUS SYSTEM A Screens.
  
• Press to scroll through STATUS SYSTEM B Screens.
• Press to go to SETPOINT Screens.
• Press to scroll through SETPOINT Screens.

Protected Screens Map

• Refer to the following map when navigating through the LCD Protected Screens. From the WSHP Screen, press the <ENTER> twice until you get to the SOFTWARE Screen. Then hold the <UP> button for 5 seconds. To scroll through the rest of the screens, press the <MENU> button.

Main Screens Map

• Refer to the following map when navigating through the Main Screens. From the WSHP AAON Screen, press <ENTER> to scroll through the screens.
• S/A Mode means the controller is in Stand Alone Mode
• WATER CIRCUIT CONFIGURATION
• SINGLE (Typical for AAON Coil) or DUAL (Typical for AAON Tulsa)
• REVERSING VALVE CONFIGURATION
• OFF=COOL (No signal on reversing valve input equals cool mode)
• OFF=HEAT (No signal on reversing valve input equals heat mode)

Alarm Screens
Refer to the following map when viewing the Alarm Screens. These screens will display automatically when alarms are present.The alarms as is follows:
NO ALARMS: This will be shown if there are no current alarms.
COMPRESSOR LOCKOUT (1-4):

• If a circuit’s Suction Pressure falls below the Low Suction Pressure Setpoint for longer than one minute twice within a two hour window, the compressor on that circuit will be locked out. Manual reset or change of mode is required to return to normal operation.
• If the Suction Pressure falls below the Unsafe Suction Setpoint for 5 seconds, that circuit’s compressor will locked out. Power will need to be cycled to restart the unit.
• If the Leaving Water Temperature falls below setpoint, the last compressor will be locked out until the Leaving Water Temperature rises 6 degrees above setpoint.
• The Leaving Water Temperature remains below setpoint for 1 minute or falls 3 degrees below setpoint. This alarm will disable when the leaving water temperature rises 12 degrees above the setpoint.

LOW H2O: The Leaving Water Temperature has dropped below setpoint. This alarm will disable when the leaving water temperature rises 6 degrees above the setpoint.

NO PROOF OF FLOW: There is a call for a compressor and there is no Proof of Flow Input Enable for more than 3 minutes or if during Heat Pump heating, the Proof of Flow Enable is open for more than 2 seconds. This alarm will disable when Proof of Flow is enabled.

LOW SUCTION PRESSURE: The Circuit’s Suction Pressure has dropped below the Low Suction Pressure for longer than one minute. This alarm will disable ten minutes after Suction Pressure rises above the setpoint.

System A Status Screens

• Refer to the following map when navigating through the System A Status Screens. From the SYSTEM A STATUS Screen, press <ENTER> to scroll through the screens.
• Status Screens shown below will scroll automatically if LCD display is left on this screen for 20 seconds.
• SYSTEM A, COMPRESSOR 1
  This screen displays the current status of the A1 Compressor. OFF PENDING: Compressor is off, but a request is made to be on, but the 1 minimum off time has not been met.
• ON: HEAT or Cool REASON FOR FAILURE: Low Pres, Lockout, Low H2O, No Flow
• This screen displays the current status of the A2 Compressor. OFF
• PENDING: Compressor is off, but a request is made to be on, but the 1 minimum off time has not been met.
• ON: HEAT or Cool REASON FOR FAILURE: Low Pres, Lockout, Low H2O, No Flow
• SYSTEM A, COMPRESSOR 1 PRESSURE READING
• SYSTEM A, COMPRESSOR 2 PRESSURE READING If Single Water Confi guration, this screen will display “NOT USED.”
• ANALOG OUTPUT 2 PERCENT 0 – 100%

System B Status Screens

• Refer to the following map when navigating through the System B Status Screens. From the SYSTEM B STATUS Screen, press <ENTER> to scroll through the screens.
• If System B is disabled, the above screen will appear.
• Status Screens shown below will scroll automatically if LCD display is left on this screen for 20 seconds.
• SYSTEM B, COMPRESSOR 1 This screen displays the current status of the B1 Compressor. OFF
• PENDING: Compressor is off, but a request is made to be on, but the 1 minimum off time has not been met.
• ON: HEAT or Cool REASON FOR FAILURE: Low Pres, Lockout, Low H2O, No Flow
• SYSTEM B, COMPRESSOR 2 This screen displays the current status of the B2 Compressor. OFF
• PENDING: Compressor is off, but a request is made to be on, but the 1 minimum off time has not been met.
• ON: HEAT or Cool REASON FOR FAILURE: Low Pres, Lockout, Low H2O, No Flow
• If Single Water Confi guration, this screen will display “NOT USED.”
• ANALOG OUTPUT 4 PERCENT 0 – 100%

Setpoint Screens

• Refer to the following map when navigating through the Setpoints Status Screens. From the SETPOINTS SCREENS, press <ENTER> to scroll through the screens.
• Note: The following screens are Status Screens. The Setpoints can’t be changed from these screens

LOW SUCTION PRESSURE HEAT MODE SETPOINT

Glycol %	Low Suction Heat Setpoint		Glycol %	Low Suction Heat Setpoint
0%	96 PSI		25%	62 PSI
5%	89 PSI		30%	55 PSI
10%	83 PSI		35%	47 PSI
15%	78 PSI		40%	43 PSI
20%	71 PSI

Glycol %	Low Leaving Water Temperature Setpoint		Glycol %	Low Leaving Water Temperature Setpoint
0%	37ºF		25%	15ºF
5%	34ºF		30%	9ºF
10%	30ºF		35%	2ºF
15%	27ºF		40%	0ºF
20%	20ºF

Configuration Screens

• Refer to the following map when navigating through the Configuration Screens. From the CONFIG Screen, press <ENTER> to scroll through the screens and change setpoints. Use the <UP> and <DOWN> arrow keys to change your selections. Press <ENTER> to save any changes.
• SINGLE: One cooling tower for all compressors on this module
• DUAL: Two cooling towers for compressors on this module
• One cooling tower for all co.mpressors on this module
• Choose between 0,5,10,15,20,25,30,35,40 percent glycol.
• OFF=HEAT: When the reversing valve input is off, the valve will be in heat mode
• OFF=COOL: When the reversing valve input is off, the valve will be in cool mode
• This screen does not apply to R454-B units.
• A1 / B1 (default): Select this for new current configurations.
• A1 / A2: Select this for “specific” older configurations.

Diagnostic Screens

• Refer to the following map when navigating through the Diagnostic Screens. From the DIAGNSTC Screen, press <ENTER> to scroll through the screens.

Force Outputs Screens

• Refer to the following map when navigating through the Force Screens. From the FORCE OUTPUTS Screen, press <ENTER>. At the FORCE MODE ON/OFF screen, press the <UP> arrow key to turn the FORCE MODE on and press the <DOWN> arrow key to turn the FORCE MODE off. Use the <UP> and <DOWN> arrow keys to increase and decrease the percentage.

Troubleshooting

Safety Monitoring for Single Water Circuit

Proof of Flow

• If there is a call for a compressor and there is no Proof of Flow Input Enable:
  • The module will wait up to 3 minutes to activate the Proof of Flow Alarm LED(s) which will blink the code indicating failure.
• If the compressor(s) is (are) running and contact is opened for 2 seconds during Heat Pump Heating: • Compressor(s) will be turned off.
• If the compressor(s) are running and contact is opened for 2 seconds during Cooling: • Proof of Flow Input will be ignored. • No alarm will be generated.

Low Suction Pressure Detection

• If any Circuit’s Suction Pressure falls below the Low Suction Pressure Setpoint for longer than 1 minute, then the following will occur:
  • The compressor(s) on that circuit will turn off.
  • Alarm LED will indicate Low Suction Pressure.
  • Compressor(s) will be enabled again after 10 minutes if Suction Pressure rises above setpoint.
• If any Circuit’s Suction Pressure falls below the Low Suction Pressure Setpoint for longer than 1 minute a second time within a two hour window, then the following will occur:
  • The compressor(s) on that circuit will be locked out.
  • Alarm LED will indicate a Compressor Lockout.
  • Manual reset or change of mode (i.e., Cool to Heat) must occur to reset back to normal operation. Unsafe Suction Pressure Detection If the Suction Pressure falls below the Unsafe Suction Setpoint for 5 seconds, the circuit’s compressor will be locked out immediately and will not be allowed to restart. You will need to reset the Power to restart the unit.

Low Leaving Water Temperature

Note: This safety monitoring is only performed in the Heat Mode.

• If the Leaving Water Temperature falls below setpoint, the following will occur:
  • The last compressor will turn off.
  • Alarm LED will indicate Compressor Low Water Temp Shutoff
  • Last compressor will be locked out until the Leaving temperature is 6 degrees above setpoint.
• 2. If the Leaving Water Temperature remains below setpoint for 1 minute or falls 3 degrees below setpoint, the following will occur:
  • All compressors will deactivate.
  • Alarm LED will indicate Compressor Low Water Temperature Shutoff
  • All compressors will be locked out until the Leaving Temperature is 12 degrees above setpoint.

Temperature Sensor Testing

• The following sensor voltage and resistance tables are provided to aid in checking sensors that appear to be operating incorrectly. Many system operating problems can be traced to incorrect sensor wiring. Be sure all sensors are wired per the wiring diagrams in this manual. If the sensors still do not appear to be operating or reading correctly, check voltage and/or resistance to confirm that the sensor is operating correctly per the tables. Please follow the notes and instructions below each chart when checking sensors.

Temperature – Resistance – Voltage for Type III 10 K Ohm Thermistor Sensors
Temperature (ºF)	Resistance (Ohms)	Voltage @ Input (VDC)
-10	93333	4.620
-5	80531	4.550
0	69822	4.474
5	60552	4.390
10	52500	4.297
15	45902	4.200
20	40147	4.095
25	35165	3.982
30	30805	3.862
35	27140	3.737
40	23874	3.605
45	21094	3.470
50	18655	3.330
52	17799	3.275
54	16956	3.217
56	16164	3.160
58	15385	3.100
60	14681	3.042
62	14014	2.985
64	13382	2.927
66	12758	2.867
68	12191	2.810
69	11906	2.780
70	11652	2.752
71	11379	2.722
72	11136	2.695
73	10878	2.665

Table 5: Temperature/Resistance for Type III 10K Ohm  Thermistor Sensors, continued

Thermistor Sensor Testing Instructions

• Use the resistance column to check the thermistor sensor while disconnected from the controllers (not powered). Use the voltage column to check sensors while connected to powered controllers. Read voltage with meter set on DC volts. Place the “-” (minus) lead on the GND terminal and the “+” (plus) lead on the sensor input terminal being investigated. If the voltage is above 5.08 VDC, then the sensor or wiring is “open.” If the voltage is less than 0.05 VDC, then the sensor or wiring is shorted.

Suction Pressure Transducer Testing for R454-B Refrigerant

• The Evaporator Coil Temperature is calculated by converting the Suction Pressure to Temperature. The Suction Pressure is obtained by using the Suction Pressure Transducer, which is connected into the Suction Line of the Compressor.
• Use the voltage column to check the Suction Pressure Transducer while connected to the WSHP-454 Module. Read voltage with a meter set on DC volts. If the temperature/voltage or pressure/voltage readings do not align closely with the chart, your Suction Pressure Transducer is probably defective and will need to be replaced.

Using LEDs to Verify Operation

• The WSHP-454 Module is equipped with LEDs that can be used to verify operation and perform troubleshooting. There are LEDs for communication, operation modes, diagnostic codes, and relays. The Module has twenty LEDs—one used for power, one used for communications, one used for operation status, one used for alarms, five used for compressor relays, four used for Suction Pressure Transducer status, and seven used for Binary Input status. See Figures 6, page 24 & Figure 7, page 25 for the LED locations.
• The LEDs associated with these inputs and outputs allow you to see what is active without using a voltmeter.

Operation Status LEDs

• “STATUS” – This is the status blink code LED. It will light up and first blink the address of the Module. It will then blink out the Mode of Operation. See Table 6 below for Status Blink Code descriptions. The blink code descriptions are also located on the Module’s front cover. See Figure 6 for the location.

“ALARM” – This is the diagnostic blink code LED. It will light up and blink out diagnostic codes. See Table 7 below for Diagnostic Blink Code descriptions. The blink code descriptions are also
located on the Module’s front cover. See Figure 6 for location

No of Blinks	Status
1	Off Mode
2	Cool Mode
3	Heat Mode

Table 6: Status LED Blink Codes

No of Blinks	Alarms
1	Low Suction Pressure
2	Compressor Lockout
3	Water Flow Failure
4	Low Leaving Water Temperature

Table 7: Alarm LED Blink Codes

SUCTION PRESSURE TRANSDUCER COIL PRESSURE, TEMPERATURE, AND VOLTAGE CHART FOR R454 REFRIGERANT
Temperature (°F)	Temperature (ºC)	Pressure (psi)	Signal DC Volts
25.88	-3.4	80.94	1.8
29.42	-1.4	87.16	1.9
32.81	0.5	93.39	2.0
36.05	2.6	99.62	2.1
39.16	4.0	105.84	2.2
42.15	5.6	112.07	2.3
45.02	7.2	118.29	2.4
47.79	8.8	124.52	2.5
50.47	10.3	130.75	2.6
53.06	11.7	136.97	2.7
55.57	13.1	143.20	2.8
57.99	14.4	149.42	2.9
60.36	15.8	155.65	3.0
62.65	17.0	161.88	3.1
64.88	18.3	168.10	3.2
67.05	19.5	174.32	3.3
69.16	20.6	180.55	3.4
71.23	21.8	186.78	3.5
73.24	22.9	193.00	3.6
75.20	24.0	199.23	3.7
77.12	25.1	205.46	3.8
79.00	26.1	211.68	3.9
80.83	27.1	217.91	4.0
82.63	28.1	224.14	4.1
84.39	29.1	230.36	4.2
86.11	30.1	236.59	4.3

Suction Pressure Transducer LEDs
“PRES 1-4” – There are LEDs for each of the Suction Pressure Transducers. Since each compressor has a sensor, these LEDs which  are located on the top left of the WSHP-454 Module will give a better indication of which compressor is causing an alarm. See Table 9 for PRES LED status descriptions. See Figure 7 for locations.

No of Blinks	Status
Solid On	Sensor is Detected and is OK
Solid Off	Sensor is Not Detected
1	Low Suction Pressure on this Compressor
2	Compressor is Locked Out

Table 9: PRES 1-4 LED Blink Codes

LED Diagnostics

• “POWER” LED: When the WSHP-454 Module is powered up, the POWER LED (located above the address switches) should light up and stay on continuously. If it does not light up, check to be sure that the power wiring is connected to the board, the connections are tight, and the controller is powered (if connected). If after making all these checks, the POWER LED does not light up, the module is probably defective.
• “COMM” LED: When the WSHP-454 Module is powered up while in Stand Alone Mode, the COMM LED does not light up.
• “STATUS” LED: As previously described, when the WSHP Module is first powered up, the STATUS LED will blink out the Mode of Operation.
• “ALARM” LED: As previously described, this LED will blink on and off to indicate alarms and diagnostics.
• NOTE: The WSHP-454 Module contains no user-serviceable parts. Contact qualified technical personnel if your Module is not operating correctly.