- Jun 2, 2008
- 5,023
- Boat Info
- 1998 450 Sundancer, Achilles dinghy w/15hp
- Engines
- 3126 Cat's
I will be starting down this rabbit hole very soon. Our boat trips the newly updated power poles with the GFCI outlets...
Tripping the Breaker at the dock Pole
- Thread starter dtfeld
- Start date
i was also going to recommend you check behind the inlets. My previous boat, although not built at Merritt island, had a similar condition and it was a failed neutral wire on the back side of the inlet. It smoked the wire and also nearly caused a fire
It’s one of the reasons The only thing I leave powered up on the boat is the battery charger and the cabin fridge. My theory is the less draw while I’m away the better, just in case something failed or heated up.
that reminds me I really planned on replacing those inlets as a precaution.
brewster16
Well-Known Member
Me too
- Sep 25, 2016
- 1,251
- Boat Info
- 300 Sundancer 1994, trailered tri-axle LoadRite roller
- Engines
- Mercruiser 5.7 260HP Alpha One Gen II, twin
@fwebster and @Strecker25 absolutely hate those 30A twist locks.
And while it could be the issue you're lucky if it trips the breaker, more often then that they just start a fire.
A 1930s industrial electrical design that was never meant for marine use. Introduced to boats at a time when a battery charger and a coffee pot was the only AC on the boat. Now we run stoves, microwaves, HVAC, refrigerators and freezers. Which is why most of you guys with 380/400/410 have two 30A cables. And that's getting to be not enough power.
AC electrical is actually a low cause of boat fires only 17%, DC is 35% with 21% of that the engine harness.
Check your engines for brittle or chaffed wiring.
But I did have a source somewhere that point the 30A inlet as the cause in over 50% of those AC related fires.
https://www.boatus.com/expert-advic...e/2021/february/analyzing-onboard-fire-claims
My upgraded electrical, 50A 230V with RCD.
Water heater and stove are 230V also now.
And while it could be the issue you're lucky if it trips the breaker, more often then that they just start a fire.
A 1930s industrial electrical design that was never meant for marine use. Introduced to boats at a time when a battery charger and a coffee pot was the only AC on the boat. Now we run stoves, microwaves, HVAC, refrigerators and freezers. Which is why most of you guys with 380/400/410 have two 30A cables. And that's getting to be not enough power.
AC electrical is actually a low cause of boat fires only 17%, DC is 35% with 21% of that the engine harness.
Check your engines for brittle or chaffed wiring.
But I did have a source somewhere that point the 30A inlet as the cause in over 50% of those AC related fires.
https://www.boatus.com/expert-advic...e/2021/february/analyzing-onboard-fire-claims
My upgraded electrical, 50A 230V with RCD.
Water heater and stove are 230V also now.
- Sep 25, 2016
- 1,251
- Boat Info
- 300 Sundancer 1994, trailered tri-axle LoadRite roller
- Engines
- Mercruiser 5.7 260HP Alpha One Gen II, twin
So if it is the inlet great, simple, but given the description I'm not so sure.
So for those that are fighting with the new shore side ELCI pedestals.
Here a a bit more explanation on where faults can be and how to find them.
First things that @dtfeld started and are the good simple things.
1. moved to another pedestal, still tripped, so not the dock.
2. changed shore cords (switch with a neighbor), still tripped, so not the cords.
3. turned off everything on the boat including the main breaker, did not trip, so not likely the inlet but worth checking.
4. main breaker on, branch circuits off, did not trip, so not the main breaker nor likely in the panel itself.
5. turn on branch circuits one at a time, try devices on the branch, held until he turned on devices.
If lucky it will consistently be a specific branch and device.
But of course we often need to deal with Colonel Murphy.
So these are the easy step by step now I going to show when this works well, and why often it does not.
It depends where the leakage to the ground side is occurring.
We all know that a dead short (a current leak) from hot to neutral or ground will (damn well better) trip the branch breaker. But ground faults are small high resistance leaks rarely a dead short between wires.
This is what makes them deadly, not enough to trip a breaker, but more than enough to kill you.
So if the leak is between the hot and ground, every time we close breaker 2, we should trip the pedestal.
If we leave #2 open all else should work ok.
But if the fault is between the neutral and the ground the current flow is much more devious.
We close breaker #2 and the pedestal trips, so we leave it open.
So we have breaker 2 open, we go to use circuit 1 (really any other circuit) and the pedestal still trips.
Why? The fault is in the #2 circuit!
Because as I mentioned initially two wires in parallel will share the load. If we look at the current flow we see that Circuit #1 can use BOTH the normal neutral path AND the fault path thru ground to get back to the marina source panel where they are connected together. And again this fault could be to the ground wire OR it could be neutral to water. So an AC pump, wet bilge, hull fitting.
So for those that are fighting with the new shore side ELCI pedestals.
Here a a bit more explanation on where faults can be and how to find them.
First things that @dtfeld started and are the good simple things.
1. moved to another pedestal, still tripped, so not the dock.
2. changed shore cords (switch with a neighbor), still tripped, so not the cords.
3. turned off everything on the boat including the main breaker, did not trip, so not likely the inlet but worth checking.
4. main breaker on, branch circuits off, did not trip, so not the main breaker nor likely in the panel itself.
5. turn on branch circuits one at a time, try devices on the branch, held until he turned on devices.
If lucky it will consistently be a specific branch and device.
But of course we often need to deal with Colonel Murphy.
So these are the easy step by step now I going to show when this works well, and why often it does not.
It depends where the leakage to the ground side is occurring.
We all know that a dead short (a current leak) from hot to neutral or ground will (damn well better) trip the branch breaker. But ground faults are small high resistance leaks rarely a dead short between wires.
This is what makes them deadly, not enough to trip a breaker, but more than enough to kill you.
So if the leak is between the hot and ground, every time we close breaker 2, we should trip the pedestal.
If we leave #2 open all else should work ok.
But if the fault is between the neutral and the ground the current flow is much more devious.
We close breaker #2 and the pedestal trips, so we leave it open.
So we have breaker 2 open, we go to use circuit 1 (really any other circuit) and the pedestal still trips.
Why? The fault is in the #2 circuit!
Because as I mentioned initially two wires in parallel will share the load. If we look at the current flow we see that Circuit #1 can use BOTH the normal neutral path AND the fault path thru ground to get back to the marina source panel where they are connected together. And again this fault could be to the ground wire OR it could be neutral to water. So an AC pump, wet bilge, hull fitting.
- Jun 5, 2016
- 5,545
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
Got a couple hours to troubleshoot. I followed @hughespat57 directions, but I couldn't isolate the problem to a single circuit/breaker.
Knowing that my main AC unit was the one thing that stopped working at the same time as this problem started, I decided to unwire the Compressor/blower unit from the the control box. Once the neutral conductor from the control box was disconnected it was all most all back to normal...at least none of the remaining circuits caused the dock circuit breaker to trip.
However, I have a single pump for the two inside AC units and the share a pump trigger box. I had to leave the pump wires connected to the main salon AC control box, but the power wire were removed. If I disconnected those trigger wires, the pump wouldn't come on for the front AC. I think the trigger wires are mis-wired. I didn't have time to sort that out.
But at lease I have the battery charger going in case the pumps bilge pumps are needed.
Knowing that my main AC unit was the one thing that stopped working at the same time as this problem started, I decided to unwire the Compressor/blower unit from the the control box. Once the neutral conductor from the control box was disconnected it was all most all back to normal...at least none of the remaining circuits caused the dock circuit breaker to trip.
However, I have a single pump for the two inside AC units and the share a pump trigger box. I had to leave the pump wires connected to the main salon AC control box, but the power wire were removed. If I disconnected those trigger wires, the pump wouldn't come on for the front AC. I think the trigger wires are mis-wired. I didn't have time to sort that out.
But at lease I have the battery charger going in case the pumps bilge pumps are needed.
Skybolt
Well-Known Member
- Nov 11, 2014
- 6,404
- Boat Info
- Reel Nauti
460 EC
- Engines
- Detroit 6v92TA
(Low profile's)
Alison Gears
Westerbeke
12.5kw Genset
Dave, curious what the resolution was. Was it the AC pump wires? But if so why did it work for a while?
Last edited:
- Jun 5, 2016
- 5,545
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
The main issue was a shorted Main cabin AC compressor, but a complicating factor was someone had criss crossed the neutrals in the pump relay box.
