HELP! I've lost half of the electrical AC power!

[MarioG]

HELP! Just finished setteling down to take a break when all of a sudden the generator started slowing down and the lights started dimming. The genny came back up to speed but the right side of the AC pannel is dead. I troubleshooted and was able to figure out that if I swapped the two black heavy gauge wires comming from the generator to the "in" side of the Main breakers next to the genny I could get the right side of the AC pannel working but now the left side of the AC pannel is dead! I'm not sure if it's the generator or if it's the breakers. I guessing it's one of the lines comming off the genny.
I hope it's an easy fix, we got guests this whole weekend

HELP!

Onan MDJF 15Kw

 

[Fanfare]

Sounds like one leg of your 110 v is out. You have probably cycled all switches and circuit breakers to reset (on>off>on). My new generator has circuit breakers mounted at the generator as required by code now. These don't show on the wiring diagrams as they were not original. Now have to have a fuse or breaker within three feet of the alternator or something like that. Have a look.

Do you have power using shoreline? If so, you could swap shore breaker for generator breaker.

Generator slowing is showing possible short. I had the ballast in one of my head fluorescent lights short out and the breaker for that side of boat shut everything on that side down. I tracked that by shutting all branch breakers off, then switching one at a time on until I found the bad circuit. Then you can just shut that circuit down until you have time to fix it.

Good luck. I hate it when this happens. Always with guests coming.

 

[Finalee]

Hope the electricians on the forum show up soon for you. Did you have a heavier load than usual on the system when this happened?

 

[Trojan]

In order to find the problem you will need an ac volt meter. I would guess that you have lost a leg in the generator. You must test with a meter and figure whether the problem is in the breaker panel or in the generator. In as much you said the generator slowed. It indicates like a short and a over load resulted. This could easily be a short in the generator. Turn off the breaker panel and take a voltage reading. If the generator runs at the correct RPMs now and you do not have the correct voltages at each leg. Then the short has opened in the generator. If you have an alternator and not a generator. You may have lost the diode bridge causing a leg loss. If you have a generator and the leg is bad. You will need to pull the generator out for a rework. You can not isolate the trouble without a meter. You should not use the generator until you find the the trouble. Due to the risk of a fire.

BILL

 

[Fanfare]

If you have 220 volts it's not the generator. See if your stove works. I'm still betting faulty breaker, or a circuit short, and the breaker's doing its job.

 

[MarioG]

Fanfair your right one of the legs is out! in fact I just retraced the lines comming from the main gen. breakers back to the generator. the lines entered a small box. I uncovered the box and found one of the legs shorted. There is a heavy bolt style connector that connects the wires comming out of the generator to the lines leading to the breaker box. it must of grounded itself against the housing. it appears that I have just enough wire left where I can reattach the wires again.

I'm off to Home Depot in hopes can find a similar connector.

I'll report back!
Thanks guys!!!!!!!!

 

[MarioG]

Re: HELP! I've lost half of the electrical AC power! (UPDATE!!)

I went to Ace hardware and found the same exact connector! I got back to the boat and cleaned up the burned ends of the wires. installed the new connector, and taped up the connections. Finished by 11:30 am. started up the generator and low and behold the power was back! just in time for the guest to arrive! You guys are the best! and I have learned a lesson on generator 101 never take things for granted and I have the best boat in the world! the problem was easy to trouble shoot and you guys gave me the lead I needed to figure this thing out. I spent aproximately $10.00 to fix the genny. I'm sure it would have cost me well over $300 for the same fix with a "professional" Onan tech.

Party's over and I'm going to bed!

Thank you!

Mario

 

[Pascal]

glad you got it!

i would still wonder why the connection shorted out in the first place though, it shouldn't have.

 

[67hat34c]

was the nut loose? Any corrosion?.

Spray Bosheild on all electrical connections.

Mario I would go ahead and check all connections in the system including the breakers, just to be safe. One problem could be an indication of others to come.

Reminds me that I need to go through evertying on ours again. We had amp meter melt down due to loose connection about 1.5 yrs ago.

 

[MarioG]

I checked the breakers and the connections behind the generator pannel next to the lower helm so far things seem normal . I did have another problem the next day with the PC board. one of the long, rectangular shaped electronic part of the board broke one if the soldered legs off the board. The Gennerator would start and run normally but it would not put out any electricity. I was able to quick fix the problem by placing the broken leg back in the hole where the weld broke loose. I kept it there by compressing a small, plastic funnel over the part and holding it down with the PC board housing cover. Luckly the fix was able to get me through the weekend, today it will get repaired correctly.