24/7 Emergency Technical Support

Services

Generator Synchronizing & Load Sharing

Paralleling is one of the few moments in an engine room where a half-second error costs a shaft. An out-of-phase breaker closure does not always leave a visible mark — it leaves a generator that is 'not quite right' for months.

We set up and verify the whole sequence: check synchronizer, breaker closing time, load ramp, kW sharing through the governor and kVAr sharing through the AVR, together with the protections that must catch it when something goes wrong.

Scope of work

  • Automatic synchronizer setup: dV, df and dφ windows, breaker closing-time compensation
  • Check-synchronizer verification as an independent protection
  • Isochronous or droop governor configuration per application
  • kW load sharing between gen-sets of different rating or make
  • kVAr / power-factor sharing via AVR and elimination of circulating currents
  • Reverse-power, overcurrent and unbalance protection settings
  • Loading and load-rejection testing with recorded results

Typical symptoms & failures

  • A hard thump or vibration at the moment the breaker closes
  • The synchronizer hunts and never locks inside the window
  • Unequal kW split — one machine at 90%, the other at 20%
  • High circulating currents and heating with no matching useful load
  • Reverse-power trip when unloading a generator
  • Frequency instability after every load step

What you receive

  • Synchronizing and protection settings recorded before and after
  • kW/kVAr measurements per generator at no fewer than three load points
  • Paralleling and load-rejection test protocol
  • Findings on any governor or AVR needing service

Equipment & protocols

  • Automatic synchronizers and load sharers, analogue and digital
  • Electronic governors and actuators, mechanical governors in droop
  • AVRs with cross-current compensation and paralleling CTs
  • Power-quality instruments and recorders

From the field

Synchronising a generator onto the main switchboard: synchroscope on a DEIF unit, 50.36 Hz / 402 V on the machine against 50.02 Hz / 401 V on the busbar
Synchronising a generator onto the main switchboard: synchroscope on a DEIF unit, 50.36 Hz / 402 V on the machine against 50.02 Hz / 401 V on the busbar

Frequently asked questions

Can generators of different makes be paralleled?

Yes, and it is common on vessels with a retrofit history. It needs careful droop and AVR setup so the machines share proportionally rather than absolutely.

Why does a healthy-looking generator go to reverse power?

Usually it is governor setup or unloading sequence, not a machine fault. We check the ramp and the command order before touching the engine.

How often should synchronizing be checked?

As part of the annual survey, and always after any work on a governor, AVR, breaker or controller.

Send us the problem

Describe the system, the vessel and what you are seeing. You get back a concrete intervention plan and a defined scope of work.