Skip to content 
QUESTIONS: 2PCS GENSETS with parallelling systems, turn on bith generator, so that 1 unit in standby and the other start working with the load or the will be only 1 breaker to turn on the 1st generator, and once the load over 80% the 2 nd generator will automatically start ?
ANSWER: The two modes you mentioned are actually different operating strategies in the generator parallel system. The specific working methods are as follows:
- One unit is in operation and one unit is on standby (hot standby mode)
- Advantages: The standby unit is on standby at any time. Once the operating unit fails, it can be quickly switched, which is suitable for scenarios with extremely high requirements for power supply continuity (such as hospitals and data centers).g voltage, frequency, and phase). After being connected to the grid, the two generators share the load.
- Operation logic: Start the first generator first, and carry the load by closing the circuit breaker. The second generator is in “standby state” (started but not connected to the grid).
- Switching conditions: When the load of the first generator exceeds the set threshold (such as 80%), the parallel cabinet will trigger the synchronous grid-connected process of the second generator (adjusting voltage, frequency, and phase). After being connected to the grid, the two generators share the load.
- Advantages: The standby unit is on standby at any time. Once the operating unit fails, it can be quickly switched, which is suitable for scenarios with extremely high requirements for power supply continuity (such as hospitals and data centers).
- Single unit operation, automatically start the second unit when the load exceeds 80% (intelligent expansion mode)
- Operation logic: Initially, only the first generator is started, and the load is carried by the circuit breaker. The second generator is in “stop state”.
- Startup conditions: When the load of the first generator exceeds 80%, the parallel cabinet first sends a signal to start the second generator. After it reaches the rated speed, it starts to synchronize parameters (voltage, frequency, etc.). After the conditions are met, it is connected to the grid and the two generators carry the load together.
- Advantages: When the load is light, only one generator is running, which consumes less energy; when the load is heavy, the capacity is automatically expanded, which is suitable for scenarios with large load fluctuations (such as factories and commercial buildings).
