A method for controlling a vapour compression system (1) including two or more evaporators (5, 12), each evaporator (5, 12) being arranged in thermal contact with a refrigerated volume, the refrigerated volumes storing goods of various types, and each evaporator (5, 12) receiving refrigerant via an expansion device (6, 13) is disclosed. In response to receipt of a load shedding command originating from a power grid (17), the vapour compression system (1) reduces a compressor capacity of the compressor unit. The refrigerated volumes are divided into at least two prioritized categories of refrigerated volumes, where a first category (18) includes refrigerated volumes storing goods of a temperature critical type, and a second category (19) includes refrigerated volumes storing goods of a temperature non-critical type. Refrigerant supply to the evaporator(s) (5, 12) being in thermal contact with the refrigerated volume(s) of the second category (19) is discontinued, and refrigerant supply to the evaporator(s) (5, 12) being in thermal contact with the refrigerated volume(s) of the first category (18) is continued. Thereby the vapour compression system (1) is capable of providing load shedding services for an extended period of time without compromising temperature critical storage.

A compressor fault diagnostic apparatus including a current sensing unit to sense a current flowing through a motor of the compressor, a fault diagnostic unit to determine whether or not the motor performs a reverse rotation based on the current flowing through the motor, and a cut-off unit to remove power based on a determination of the fault diagnostic unit.

A compressor fault diagnostic apparatus including a current sensing unit to sense a current flowing through a motor of the compressor, a fault diagnostic unit to determine whether or not the motor performs a reverse rotation based on the current flowing through the motor, and a cut-off unit to remove power based on a determination of the fault diagnostic unit.

A heating, ventilation, and air conditioning (HVAC) system is configured to receive a signal from a thermostat. The signal instructs the HVAC system to operate a component in a partial load mode. The HVAC system is further configured to determine that the component has exceeded its operating envelope. In response to determining that the component has exceeded its operating envelope, the HVAC system is configured to operate the component according to an override configuration. The override configuration overrides the signal to operate the component in the partial load mode.

In order to improve a refrigerant compressor comprising a drive motor and a compressor unit which compresses a refrigerant entering through a suction inlet and allows it to exit through a pressure outlet in such a way that it works as reliably as possible, it is proposed that the refrigerant compressor comprise a compressor monitoring system which is integrated into a compressor control system and which determines a compressor condition by means of a first condition value that corresponds to a first saturation temperature in the suction inlet and a second condition value that corresponds to a second saturation temperature in the pressure outlet, and which compares the compressor condition with permissible compressor conditions lying in a given deployment field of a deployment diagram and initiates a process of switching-off the refrigerant compressor if the compressor condition departs from the deployment field.

A heating, ventilation, and air conditioning (HVAC) system is configured to receive a signal from a thermostat. The signal instructs the HVAC system to operate a component in a partial load mode. The HVAC system is further configured to determine that the component has exceeded its operating envelope. In response to determining that the component has exceeded its operating envelope, the HVAC system is configured to operate the component according to an override configuration. The override configuration overrides the signal to operate the component in the partial load mode.