Miswired 3-phase pedestals

Is there a way to protect your RV from a pedestal miswired with a 3-phase High-Leg Delta service?

Read my previous article about 3-phase campground power HERE…

Hi Mike!

I read your reply to John Ko: "None of the 50-amp EMS/Surge Protectors actually measure L1 to L2 voltage so they won’t be aware that it’s 3-phase. And your 30-amp shore power connection won’t care at all and will work perfectly. It’s only the maintenance staff that needs to understand it."

But I also read in your article: "They ended up sending 208 Volts to half a dozen 30-amp TT-30 pedestals, which burned up the electrical systems in several RV trailers before someone metered it."

So that leaves me wondering, will my Progressive Industries EMS protect my 30 amp RV if I run into a similar incorrectly wired pedestal? - Larry Scofield

Hey Larry,

Yes it will protect your RV from a 3-Phase High-Leg Delta service. I’ve tested both a 30-amp Progressive Industries EMS and a Southwire Total Electrical Protection SurgeGuard under a variety of high-voltage miswiring conditions.

Both Surge Protectors stopped up to 240 volts from getting through to the RV’s 30-Amp shore power inlet. But be aware that a basic ($100) MOV-only surge protector won’t stop high voltage from miswired pedestal outlets since there’s no cutoff relay.

Would you like to see this?

Should I make a video of how EMS/Advanced Surge Protectors work with miswired High-Leg Delta 120/208/240-Volts? I’ll get to use my 3-phase desktop signal generator in High-Leg Delta Configuration!

😎 - Mike Sokol