Sometimes, when we are choosing a transport refrigeration unit or air conditioner for truck/van/bus, we may see some descriptions like “APU is compatible for all truck cooling”, “Split AC Electrical Standby is optional”. Laymen may confuse AC Electrical Standby with Auxiliary Power Unit, thinking that they are the same thing and both work as additional power supply when engine is off. Actually, they are quite different. Corun is going to explain their different definitions one by one.

AC Electrical Standby

Components: the AC electrical standby consists of electric motor, independent compressor, external pull power lines, refrigerant pipelines and so on.

Working principle: the AC electrical standby use the external power supply line for motor rotation, drive independent compressor work, and provide circulating refrigerant to make transport refrigeration unit work without the operation of engine at the chassis.

Position of installation: the AC electrical standby is generally installed next to the main girder of the refrigerated vehicle. Sometimes, it is installed in the inside container of the refrigerated vehicle with a small side door next to it.

The AC electrical standby of a refrigerated vehicle is the second refrigerating power source that starts when the engine at the chassis does not work or malfunctions. It can be used as a temporary cooling solution to work under some unexpected situations, and can also turn the refrigerated vehicle to a temporary cold storage. When the electrical standby is added to the refrigerated vehicle, the compressor can keep running by connecting the AC electrical standby to external power source to maintain the temperature when the engine stops working. It is more suitable for long distance transportation and normally are applied to 7m above long refrigerated vehicle.

So much for AC electrical standby, hope you find this article useful! Corun will explain auxiliary power unit (APU) in next article. Together with Corunclima, let’s enjoy the comfort brought by worry-free transport refrigeration unit and air-conditioning system for trucks, vans, and various types of vehicles!