48 hours on genny. Electrical shorted now.

[06bowtie_guy]

Dealer installed the onan 5500 into my trailer. This weekend it was running fine. Turned it off without any issue, had been running coffee machine.

Later in the evening went to fire it back up. Powers up fine, no codes listed on the hour meter screen. Will not power up the trailer. I checked all breakers and nothing was tripped.

I followed some wiring to a junction box, have an ohm meter with me so was going to check if it was putting out power. Here is what I found.

20140921_102321 by funinmud, on Flickr

Unsure if you can tell but the white wires were in a marret with electrical tape on them. The plastic of the marret is now melted off. Not pictured is the cover that was removed, had some marks on it.

Unpacked the trailer once home and dropped it off at the dealer (they are closed today)

Curious if anyone may have an idea of damage caused, could the generator side of the unit have gotten fried because of that? They did the install so that's why it's back there now.

Thx for input!

[mrgreetis]

I learned something new - what a "marrette" is.
Tried finding a definition, that led me to this link
clicky

Never knew that...

[06bowtie_guy]

Well update. Dealer got it all fixed up. No damage to the genny which is good, ready to go for a couple more weekends before winterizing.

They changed out the basic marett for the one with set screw. Should stay together now.

[06bowtie_guy]

thanks for all the replies.
Yes I was curious why tape with those connectors. All breakers were ok. Trailer had the gen prep package so wire sizes should be correct.

Coffee maker is a kureg that I use then turn off once done. When the 3 of us are out i'm the only coffee drinker so on, use it then off.

Well I hope they can fix it up right as I'm still hoping for a couple of weekends out before winterizing!

[MEXICOWANDERER]

I've been using Euro-Terminals for 20 years. They have a tension tang between the set screw and wires to be clamped. The slotted set screw has a slight interference fit to the housing threads. This means the set screw is not loose and does NOT rely on compression of the conductors to stay tight. Nylon housing. The six gauge model is good for 65 amps at 240vac. This fastener does not loosen over time. it has been a mainstay in my wire management inventory. A pair of 10 gauge wires can be paralleled into one hole with ease.

[westend]

Neutral's were not connected fully inside the wire nut. That led to the arcing and the heat. If the neutral becomes disconnected, you will have no power continuous to the RV's load center. Probably no damage to the gen set because no power is flowing through the bad connection.

[SCVJeff]

Usually when junction boxes melt as this one did, and the wiring is OK elsewhere, it's a sure sign of a lousy connection in the box. Done properly there is no reason to wrap everything in tape

[MrWizard]

That looks like an over heated neutral connection
It got really hot to melt everything that way

It's very likely now very corroded and loose inside where the wires were twisted together

That connection should be cleaned and reworked
But because it's all new it's good to have the RV dealer/installer fix this under warranty
Then measurements should be made to check the load balance on the circuits

[RoyB]

Not sure what coffee maker you have but we save alot of coffee maker time by having the CUISINART GRIND and BREW coffee maker that is only drawing a large amount of AC current for just around 5-6 minutes. Then the coffee maker shuts completely OFF. The finished coffee than pours up into a thermos CARAFE which keeps the coffee brew hot all day long. This was big power savings for us...

Just a power savings tip for you...
Roy Ken

[time2roll]

Did you check breakers on the generator?
Box looks a mess. Looks like large and small wires connected... is everything the right size?