Electrical outlet head scratcher

[kohlerguy]

I have a 05 Newmar DutchStar. I'm having trouble with 2 outlets. All other outlets work fine. These two outlets only have about 100v to each one. All others have about 118-121v. The 2 problem outlets work good as long as you don't put a heater, fan, vacuum cleaner on it. When that happens it knocks out the inverter. A quick reset and all is well again.
House batteries are both showing 13.6 volts.

Anyone have an idea what to check next. I'm assumming the inverter is good as all the other outlets will work even under load.

Any ideas?

[Lobstah]

Matt_Colie wrote:
You have bad connections along the "daisy chain" and it is probably the neutral, but that doesn't matter. RVs are all wired with solid NM cable and that is only S-Brain stupid (IMNSHO). Boats have been wired in stranded NM for decades because of the vibration. Most power boats run about 50 hours a year and they still have trouble with power wiring loosening up in the terminals.

Shut down the power and take a day and check every single connection in the system. That means every screw on every receptacle (outlet) and every wire nut and every terminal screw or buss in the main box. If you can't get a screw to tighten even a little, back it out an half a turn and run it back down.

This will be an amazing PITA, but if you do them all and don't skip any - even the one you never use in the underneath - then the problem will probably disappear.

Oh, if you find any receptacles wired as push-in (insertion), remove the conductor, strip more if needed and clamp it under a screw. Push-in just doesn't last in RVs that are actually used over the road.

Matt

X2

I learned this lesson the hard way. Being new to RV's I've been learning as I go along. 2yrs ago we were dry camping in very hot weather down in Maryland. All of a sudden, smell of smoke in the coach, and lost all A/C. Shut gen down, hit batt disconnects, isolated smell to A/C breaker panel in bathroom. Took the cover off and the nuetral connections had become loose and eventually burned through whatever connection was left. I got running again by stripping the charred insulation back and cleaning up the neutral bar and re-attaching, but that whole scenario could have ended much differently if it had started a fire.

Jim

[Matt_Colie]

You have bad connections along the "daisy chain" and it is probably the neutral, but that doesn't matter. RVs are all wired with solid NM cable and that is only S-Brain stupid (IMNSHO). Boats have been wired in stranded NM for decades because of the vibration. Most power boats run about 50 hours a year and they still have trouble with power wiring loosening up in the terminals.

Shut down the power and take a day and check every single connection in the system. That means every screw on every receptacle (outlet) and every wire nut and every terminal screw or buss in the main box. If you can't get a screw to tighten even a little, back it out an half a turn and run it back down.

This will be an amazing PITA, but if you do them all and don't skip any - even the one you never use in the underneath - then the problem will probably disappear.

Oh, if you find any receptacles wired as push-in (insertion), remove the conductor, strip more if needed and clamp it under a screw. Push-in just doesn't last in RVs that are actually used over the road.

Matt

[BrianinMichigan]

You say that the inverter gets knocked out. Are the outlets that are at 118-121 volts also hooked to the inverter?

[wny_pat1]

smkettner wrote:
Are the low voltage outlets powered by a MSW inverter?
Need a true RMS meter to be accurate.

Apparently not enough wattage to power the big stuff.
Does it have a transfer switch to pass through utility power when turned off?

X-2

[n4hwl]

What do these 2 outlets have in common? Are these the only 2 that are powered through the inverter?

[ScottG]

Are these outlets connected to a GFCI? They can go bad and cause the same thing.

[time2roll]

Are the low voltage outlets powered by a MSW inverter?
Need a true RMS meter to be accurate.

Apparently not enough wattage to power the big stuff.
Does it have a transfer switch to pass through utility power when turned off?

[tomousecap]

A friend had a simular problem which proved to be a resistance connection (loose wire connections) in the junction box of the inverter itself. The lines all connect in the chamber on the side of it. Some burning had already occurred and things were getting worse rapidly.....

[shaneperch]

I would say bad connections or a neutral that has become loose. Check the Neutrals in the distribution panel and tighten them up. then replace those two receptacles with new and put "noOx" on the connections. I still don't know why they use romex in moving vehicle with solid wire. I am going to replace all the wiring with #12 SO cable in the walls. I had bad receptacles in my HR and tightened the neutrals and installed industrial grade receptacles with extension boxes on the bad ones. My opinion anyway.

[the_bear_II]

Sounds like bad connections.

[donn0128]

Pull them out and check the voltage at the wires. Probably burned contacts in the receptacles.