Working Principle Wiring Diagram of Automatic Transfer Switch

The null line of the dual power automatic transfer switch has the following connections:

(1) 4 pole dual power supply automatic transfer switch, null (N) line separately, respectively connected to the common power grid and standby power grid null (N) line.

(2) There are two ways to connect the null line of the 3 pole dual power automatic transfer switch: one is the null (N) line of the common power supply and the standby power supply separately. The other is that the common power supply and the standby power supply are connected together. When the common power supply and standby power supply of the null line connected together, the common power supply line or standby power line, can not be installed in the upper level of the double power automatic conversion switch residual current action circuit breaker, otherwise in the double power automatic conversion switch when the residual current action circuit breaker will automatically trip.

Problems needing attention for high inductive reactance load conversion control

ATSE is generally not allowed to transfer with large motors or high inductive reactance loads, such as large motors which switch in operation, when the power phase gap is large, it will be subjected to huge mechanical stress. At the same time, the over current caused by the back potential of the motor even causes the fuse to break or the circuit breaker to trip. The solution is usually resistance absorption or load reduction, or automatic conversion switch to delay conversion type. Two groups of moving contacts are added a delay before conversion to avoid the impact current caused by switching large motor or transformer load.

ATS Wiring Diagram