“The Valden Heat Pump controller is an open source platform to precisely control heat pumps. This controller can be used for the automation of newly built Heat Pumps (HPs), as a repair controller for old systems or as control system for performing experiments on refrigeration equipment.
Specs:
- 12V 0.5A DC power supply,
- 230V output,
-4 16A relays: Compressor, Hot Circulating Pump (CP) or Air Fan, Cold CP or Air Fan, Crankcase Heater,
- 2 inputs: Hot and cold side refrigerant over/under pressure NC sensors,
- up to 12 temperature (T) sensors, -55..+125 C range,
- Electronic Expansion Valve (EEV) supported, 6 pin EEV connection: 4 * coils + 2 * 12V,
- automatically turns on/of system when heating required,
- automatic power saving mode,
- built-in protections: cold start, overheat, short-term power loss, power overload, ground loop freeze, compressor protection against liquid and other, - LED indication, - control via remote display https://github.com/openhp/Display/ or local Serial (UART 5V).
Refrigeration schemes supported:
- Heat Pump (HP) with Electronic Expansion Valve (EEV),
- HP with capillary tube or TXV,
- EEV-only controller.”