English to Russian Tech/Engineering Electronics / Elect Eng can be briefly paralleled

conditions external to the plant that may not be controllable by the plant operators - ?

First, a static phase angle between Vg and Vs may exist before the transfer is started. Secondly, the phase of V3 will make a step change when A is opened. Finally, the phase of Vs may also change when A is opened. The resultant phase difference due to these three factors may completely eliminate the possibility of using the Fast Transfer method. In addition, this entire phase angle may not be the same each time a transfer is made. The initial angle is influenced by the load on the bus at the time of transfer and conditions external to the plant that may not be controllable by the plant operators.