When operating AC generators in parallel, what must be checked and matched before connecting them?
1. Voltage
2. Frequency
3. Output current
4. Current existence
5. Phase
Refer to figure.
AC generators (otherwise known as alternators) convert mechanical energy into an alternating current.
When working in parallel and before connecting, alternators must have equal:
- Frequency: Damage can occur when there is a difference in frequency, as one generator tries to slow down and the other tries to speed up.
- Phase sequence: At any point in time, the phases of both generators must be identical (see graph).
- Voltage: the voltage output of both generators must be equal before being paralleled.
Therefore the correct answer is: “Voltage, frequency and phase”
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