Exam Question

### (a) Conditions for Paralleling an A.C. Generator
For an incoming a.c. generator (alternator) to be safely paralleled with live bus-bars, the following four critical conditions must be met simultaneously. Failure to meet these conditions can result in severe electrical and mechanical stresses, potentially causing a blackout or catastrophic damage to the equipment.
1. **Equal Voltage:** The terminal voltage of the incoming generator must be equal to, or very slightly higher than, the bus-bar voltage.
* **Reasoning:** If the incoming generator's voltage is lower, it will draw a large reactive current (kVAR) from the bus-bars upon closing the breaker, acting as an inductive load. This can cause voltage dips and instability on the grid. If the voltage is slightly higher, the generator will immediately start supplying reactive power to the system, which is the desired outcome.