Electrical Question

[jbrad]

The breaker for the cabin airconditioner will not energize when shore power 1 and 2 are on. When I turn shore power 2 off and combine panel A and B it works fine. This just started this week. Has anyone experianced this before or have any ideas or suggestions?

Thanks,

Jimmy Bradley
Mr Busy MV 059

[Stray Cat]

Are you working from two dockside power cables when not in parallel mode?
The genset, the inverter and a single shorepower cord must be in parallel mode to power the 'Bus B' branch.

Is the dockside breaker on for the cables for both shore power 1 and 2?
When a dockside breaker trips, it doesn't flip to off, rather a middle position. Cycle them both off and on again. Dockside breakers do breakdown. They will also trip off when the high startup current intrinsic to AC and refrigeration equipment cuts in, particularly when added to other loads exceeds their rating. Breakers which have tripped often loose capability, a vintage 30A breaker may drop at substantially less.

When the boat's parallel breaker is off, is there a power cord properly plugged into the boat's shore power 1 and 2 sockets?
Power cord plugs and sockets can deteriorate and pose a substantial fire risk! Open and visually check all the shore cable plugs and sockets for burn marks or improper insertion.

Is the boat panel breaker on for Shore Power 2 when the 'Parallel' is switched off?
(The little lockout bar should prevent any problems with this). Is the little green LED on?

Is the 'Reverse Polarity' light on? Big problem with the dockside power!

When you switch the 120 volt meters from the 'Test Line 1 to Line 2' position, do you get adequate voltage on both?

Does anything else on 'Bus B' work, like the Galley circuit? 'Bus A?'

Check out the thermostats. Devilish tricky gadgets those!

There is a little reset button right on top of each AC unit. Push both and try again. They will trip when the unit overheats because the air filter is plugged, or if the seawater pump fails/the seacock is turned off, or if the AC unit ices up. Or if your AC Karma Account is suffering from inadequacy.

Are there signs of a poltergeist? Have you angered a witch doctor?

Gary Bell, aka Mister Science, STRAY CAT, MV34 hull 12 at home berth, Scappoose Oregon.

[Stray Cat]

Oops!
I just re-read the original post.
The breaker can not be reset when the load is shorted.
Check out the control relay box...

[jbrad]

Gary,

Thanks for the unsights. I wenr back down to the boat with a circuit tester and found my shore power receptacle dockside had no power on #2. It seems there is a short between the main feed and the second pedestal outlet. We notified the marina and they are sending out an electrician this afternoon. It is wonderful that we have a comunity of PDQ'ers that assist each other like this. if we can ever help let us know. Thank again.

Jimmy and Jonathan
Mr Busy MV 059
Pensacola, Florida

[James Power]

Hey Jimmy, as Stray Cat mentioned, check the shore power connections at the dock pedistal and the vessel inlet for signs of corossion / overheating. I have seen a lot of this on my last tour. This can lead to galvanic isolator, inverter and battery charger " hissy fits " and possibly a fire. James