Problem:
What can the 24 volt deluxe controller do and how does it work?
Resolution:
The deluxe controls may be applied as a stand-alone control system. The stand-alone design provides accurate temperature control directly through a wall-mounted electronic thermostat. It may be easily interfaced with a field provided control system by way of the factory installed 18-pole terminal strip.
The control design requires a constant flow of water to the water source heat pump. If flow is lost, the units safety devices will trigger the unit off.
Note: The deluxe control does not operate the reversing valve. The reversing valve supplied will be in the heating mode with power off. A field provided thermostat or field provided control system must provide 24vac to the "O" terminal when cooling is required. See the diagram supplied with the unit for wiring details.
Deluxe controls include the following:
• 18-pole strip for low voltage field wiring
• For 0.5 to 5 tons, 50 VA transformer (75 VA for 6 to 25 tons)
• Anti-short cycle compressor protection (3 min on / 3 min off)
• Brown out protection
• Compressor contactor
• Compressor delay on start
• Compressor lock-out relay
• Condensate overflow
• Electric heat and compressor enable (6 to 25 tons)
• Freeze protection
• High pressure switch
• Hot gas reheat
• Low pressure switch
• Low pressure time delay
• Multi-speed fan motor • Random start delay
• Reversing valve coil
• Soft lockout mode
Note: For .5 to 5 tons, hot gas reheat and electric heat units with deluxe controls offer a 75 VA transformer.
General Alarm Contact
Contact Configuration: Isolated dry SPDT
Operation: This contacts will be closed when the control goes into a manual lockout mode for either a high pressure, low pressure, or condensate overflow condition. Terminal designators are AL1 and AL2.
Compressor Disable (Load Shed)
Function: To temporarily suspend compressor operation if 24 VAC is present at terminals CD1 and CD2.
Operation: The source of this 24VAC signal would most likely be from the water loop controller in the system. It could be disabling the compressor because of low water flow or because of peak limiting. Once the compressor has been disabled the anti-short cycle time period will begin. The input (terminal “CD” will continue to be monitored and when the compressor disable signal (24 VAC) is no longer present, the control will allow the compressor to restart provided the anti-short cycle time has expired, safeties are satisfied and the run signal is still present.
Note: This 24VAC is not from the same Class II transformer that is in the unit control panel, therefore separation of circuits requirements per UL will be necessary for the wiring of this signal into the unit.
Generic Relay
Contact Configuration: Isolated SPDT pilot duty rated
Operation: This relay could be used for a variety of control features. Specifically, it may be used for a night setback or pump restart function. An external Class II 24VAC signal will energize the relay coil on terminals “R1” and “R2”. Terminals “C” – common, “NO”- normally open, and “NC”- normally closed will be provided for the relay contacts.