Location of AVR and speed/load sharing controller for Diesel generator sets

[NickParker]

a) Installing Generator speed / load sharing controller in the engine skid.
Installing the AVR in the Generator terminal box or in the skid.
b) Installing Generator speed / load sharing controller in the dedicated control panel remote from the engine skid.
Installing AVR in the dedicated control panel remote from the engine skid.
c) Installing Generator speed / load sharing controller in the engine skid.
Installing AVR in the Switchboard to which the generator is supplying power.
d) Installing both AVR and Generator speed / load sharing controller in a dedicated control panel

Which option is better for operational convenience?
Does installing AVR in the switchboard cause any arc flash concerns?

 

[TugboatEng]

It's most convenient to put everything in the switchboard. This also protects everything from heat and vibration.

On small generator sets, I have seen circuit breakers installed in the generator terminal box to protect the wires leading to the remotely mounted AVR. Vibration causes these circuit breakers to drop parts into the generator and destroy the generator. The dealers are replacing the circuit breakers with fuses that are very sensitive to damage from vibration. I am curious to hear best practices with regards to this. My installations have the AVR in the generator enclosure with no protection and we opted not to have voltage sensing in the generator controller so that we don't have any unprotected wires leaving the generator enclosure onother than the power output.

 

[FreddyNurk]

Marine the load sharer / synchroniser probably ends up in the switchboard.
If you have the space, load share / synchroniser in a separate control panel, separate to both the switchboard and the set.
AVR is set dependent, also depends on your excitation system. Most sets I've been involved with have the AVR onboard the alternator, but if you're not going alternator OEM AVR they can be located separately. If the AVR is PMG powered much easier to have it on the alternator.

My general perspective is keep the operators away from the switchboard, and away from the set. AVRs don't generally need much adjustment during operation, so are not a high occurence issue.

 

[wcaseyharman]

I’m mostly used to utility scale machines, >10MW so this might not be super useful for your application.
Typically there are 2 separate panels in a generator : a relay panel with all the protective relays, and a generator control panel with metering, breaker control, and voltage/ load control switches. The governor/turbine controls are most often often but not always in an adjacent cabinet. The AVR occasionally is also adjacent, particularly if it’s a brushless type. Static exciters are more often off in another area near the generator and power potential transformer. Arc flash concerns are present for static exciters, but most of the high power equipment is inside the cabinet behind a door so not an issue for normal operation.
The one larger diesel genset we have, which is an old EMD MP45 2.5MW, originally had both the engine control and the AVR inside the generator compartment on the skid. In the upgrade we performed in 2023, the control vendor put the new controls in the switchboard building, but we left the AVR in the generator compartment. So far it’s been a great improvement.