Do you have a hot neutral at the Box?

Which is why I have a Progressive Industries EMS 30A (30 amp) device.

I always plug it in 1st, and it run a diagnostics check of the CG electrical system. When it tells me everything is good, I plus in my shore plug into the PI EMS 30A. The PI device will delay sending electricity down line to the RV until it has declared the CG power system to be safe.

FoehnLeigh wrote:
Second-guess your RV Park and check their power pole for any hot neutrals before you plug in your RV. Hot neutrals can be dangerous since the breakers in your RV only work when connected on the hot side. When power-pole outlets are wired backwards, a hot neutral results. This means your RV breakers will not trip during a short.

FoehnLeigh wrote:
Second-guess your RV Park and check their power pole for any hot neutrals before you plug in your RV.

No need to check anything manually if using an EMS which will do this for you, automatically ... highly recommended for every RV owner. ;)

FoehnLeigh wrote:
Second-guess your RV Park and check their power pole for any hot neutrals before you plug in your RV. Hot neutrals can be dangerous since the breakers in your RV only work when connected on the hot side. When power-pole outlets are wired backwards, a hot neutral results. This means your RV breakers will not trip during a short.

Breakers may or may not trip with a reverse polarity (hot neutral) short, depending on where the short is. A short from "neutral" to ground—what would normally be a ground fault—will not cause the breaker to trip because the fault current is not flowing through the breaker. A short from "neutral" to hot will trip the breaker, same as before, because the fault current does flow through the breaker.

Breakers are not polarity sensitive, nor indeed is there really any polarity at all on an AC circuit when viewed in isolation. They will respond to any overcurrent situation where the current flows through them.

A reversed polarity receptacle is indeed a dangerous and potentially disastrous problem; I don't want to suggest otherwise.

All you really need is a volt/ohm meter, and learn how to use it.

Captain_Happy wrote:
All you really need is a volt/ohm meter, and learn how to use it.

Or you can buy an EMS and be protected from this an a whole list of other power issues including things like brownouts that a meter can't help with. Best of all I don't have to remember to do yet another thing and spend yet more time during setup which means I'm more likely to actually go out on a weekend and use the trailer. An EMS is cheap insurance and it's a onetime purchase which means it's paying you back every time you save the time at setup.

I too recommend the Progressive Industries HW-30/50C or if you must the portable versions .. Protection against
Over voltage (Damaging to electroncis)
Under voltage (Damaging to electrice motors IE: Air Conditioners)
Over/Under Frequency (Damaging to all the above)
And connection errors
Power blinks (Damaging to air Conditioners and compressor Fridges)
And more.

Plug into a 240 volt outlet that looks like a TT-30 and.. It protects you.

Not really news to those that have been on this forum for any length of time.

ScottG wrote:
Not really news to those that have been on this forum for any length of time.

Apparently news to the OP. :W

I always check with my home made pedestal checker,cheap but it works.

Saves me the hassle of dragging everything out.Then I hookup using my Progressive Industries EMS HW-30C.


parts list
15 amp to 30 amp Adapter
triplex outlet
Outlet tester
Volt Meter
I had all these around the house,why not use them...
I also use my 50amp to 30amp adapter to check the 50amp side. Sometimes I like them better as the are in better shape.

afidel wrote:

Captain_Happy wrote:
All you really need is a volt/ohm meter, and learn how to use it.

Or you can buy an EMS and be protected from this an a whole list of other power issues including things like brownouts that a meter can't help with... An EMS is cheap insurance and it's a onetime purchase which means it's paying you back every time you save the time at setup.

I would hardly call $300-$400 "cheap insurance", especially compared to a $20 DVM.