The standard EN 14825 differentiates between 4 non-active modes of energy consumption.
- Standby (this is the mode when the device remains partially switched off and can be enabled again by a controlling device (remote control, timer, etc.).
- Thermostat Off (the device operating mode in which the cooling or heating demands of the room are covered and the device disconnects the cooling compressor).
- Power Off (in this mode the device is completely disconnected and cannot be reactivated by means of a controlling device, external signal or timer).
- Crankcase heater (in this mode the device activates a compressor oil heating device, thus avoiding the refrigerant from concentrating in the compressor oil and thereby avoiding damage to the compressor when it starts operating).
Power consumption during the thermostat off mode (Pto)
When the unit has been operating for 30 minutes in test conditions D in the cooling mode (only for refrigeration or reversible units), the thermostat set point is increased until the compressor stops. Energy consumption in standby mode is taken from the total energy consumption measured in the unit to determine the energy with the thermostat off for a period of time no less than 1 hour.
The same principle is applied in the heating mode, but the thermostat set point is reduced until the compressor stops and after the unit has been operating for 30 minutes in test conditions D.
Power consumption during the standby mode (Psb)
After the condition A test in cooling mode, the unit is stopped using the controlling device. After 10 minutes the residual energy consumption represents energy consumption in standby mode.
For heating only units, measurements are taken in the same way after testing under test conditions D in heating mode.
Power consumption in crankcase heating mode (Pck)
If the crankcase heater is on during standby mode, power consumption is considered to be equal to the electricity power consumption in standby mode.
If the crankcase heater does not operate during measurements in standby mode, after completing the test in temperature conditions B in heating mode, the unit is switched off using the controller and energy consumption of the unit is measured for 8 hours. The average input power over 8 hours must be measured.
Power consumption during the power off mode (Poff)
After the standby mode test, the unit is completely switched off. After 10 minutes the residual energy power for consumption while off is measured.
If there is not a switch to disconnect the device, the power in off mode is considered to be equal to the standby power mode.