Marina power issues

[benmin]

Main breaker at a newer marina randomly trips. It is 100ma gfci trip. The pedestals connected to it have the 30ma gfci breakers which are not tripping.
Curious as to what others have found in similar circumstance. Possibly a cumulative affect?

 

[zbang]

Certainly could be- 10ma here and 10 ma there adds up. Have you put a sensitive amp meter on the EGC? Might be able to track around for higher leakage sections.

 

[benmin]

Certainly could be- 10ma here and 10 ma there adds up. Have you put a sensitive amp meter on the EGC? Might be able to track around for higher leakage sections.

Have not yet. gearing up for the season here in the northeast. It's a issue from the previous season that I'm looking to gather some ideas.

 

[don_resqcapt19]

Yes, a common issue is the cumulative leakage on all of the boats connected to that feeder.

If it is tripping with 3 or less boats connected, I would be looking at an issue with the feeder circuit itself.

This is one of the reasons for 555.35(B) in the 2020 code.

(B) Leakage Current Measurement Device.
Where more than three receptacles supply shore power to boats, a leakage current measurement device shall be available and be used to determine leakage current from each boat that will utilize shore power.