Cannot connect to 20 amps outlet

Mein Sprinter

Known member
Hello All.. I posted this elsewhere and realized its better to ask all Roadtrekers...this might have been covered somewhere else...but...
.. this is a 2010 Sprinter Roadtrek SS Agile 2500.....; this might be soooo elementary to you but quite perplexing to me. I can charge my House/Chassis batteries perfectly fine with any 15a outlet/inlet, but not on 20a; breaker at the House circuit will "pop"; same does at RV campgrounds. WHY!!?? Is there a 750Watt Tripp-Lite RV Inverter/chargers setting for this?? Thank you..


Mein Sprinter

Known member
If you have a voltmeter check that your 20a outlet is 120 volt and not 20amp 220volt
Yes, my House is 120v... so were most Camgrounds... Even at my daughters House it's 120v. No 240v anywhere! Interesting, breakers GFI in the Van does not trip, but source from House, etc trips at the House panel!


the wiring for 120 volt 15 and 20 amp circuits is identical except for the wire gauge and the circuit breaker. A GFCI does not protect against overloads, only ground faults. Most homes in the US are fed by 3 wires, a neutral and 2 hot legs. for most circuits in a home the wire / breaker will tie into one hot leg and the neutral giving 120 volts. bigger loads like a range or dryer will have a double pole breaker that ties to both hot legs giving 208 volts.
it is also possible that the neutral is open. A voltmeter will tell you pretty quickly what voltage is present at the outlet.


Well-known member
I’m not familiar with your RV.
1) Are you using the same cord for the 15 and 20 amp connection? There are two types of 102/20amp connections. The straight bladed type, which is similar to a residential 15 amp outlet. And a twist lock type outlet, known as a NEMA L5-20.


Erratic Member
If it's a GFCI breaker at your panel, perhaps it's tripping at a far lower leakage current than your other GFCIs would trip at?
Most house breakers are NOT GFCI ... except for the bathroom and near-sink outlets.
Try running a 15 amp cord from one of those and see if it trips.

A GFIC should trip if it sees more than 5 milliamps imbalance between "hot" and "neutral" (i.e. there's leakage to Ground)

Some of the test units (like msg #5) have a button to apply a known leakage to test the GFCIs do trip when they're supposed to.



Active member
The Tripp-Lite inverter/charger is known to trip a GFCI outlet, the workaround is to turn the inverter ON before plugging in then wait a minute or two till it starts charging, then switch the inverter off using the remote switch by the sliding door.

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