Well my surge protector saved me one more time.

[WILDEBILL308]

Well my surge protector saved me one more time. Stopped off at Galveston Island State park on the way home from the FMCA 6 state rally in Conroe. Plugged my Surge Guard in and got a reading of Reverse Polarity and bad ground. Called the office and they worked on it for a while then told me it was good. Well the Surge Guard was still giving me the same report. So I ended up moving to s different spot. I am still amazed at how many people tell me they never had a problem and don’t need a Surge Guard or some other protection for their rigs. This reminds me of the old saying “Pay me now or pay me latter” If you don’t have a Surge Guard you may be paying a lot latter.
Bill

[MEXICOWANDERER]

Three stabs and you're done. Has a white LED for checking when parking at night, audio tone, and vibrator alert. Will check 120, and 240 outlets any socket configuration.

[DrewE]

Ductape wrote:
OK, I will bite.

IF the ground was open, as reported- then how was the allegedly reversed "polarity" determined?

Think about it.

Ground is "open" in that it's not bonded to supposed neutral; that is, 120V is not detected between the supposed hot and the ground line.

Reverse polarity would imply that ground is bonded to the supposed hot terminal. Most likely it's merely a reversed hot and neutral at the socket, with ground bonded to the (actual) neutral line that is connected to the (putative) hot terminal.

[road-runner]

Ductape wrote:
OK, I will bite.

IF the ground was open, as reported- then how was the allegedly reversed "polarity" determined?

Think about it.

Good catch! If this was about a 3-light tester, the answer would be an easy it's impossible for the tester to determine both conditions. Since 2 of the 3 lights are wired to the ground terminal, only 1 light could possibly light with both conditions present, and it takes 2 to indicate reverse polarity. Note however that the original post said "bad ground", which a 3-light tester could possibly show if there was some voltage on the ground wire. Similarly, I'd think the EMS could possibly detect a "poor" ground with reversed polarity but the algorithm would not be 100% accurate. No matter anyway, the PI EMS book I looked at says the only ground fault it detects is "open ground", which of course can't be detected simultaneously with polarity detection, since ground is the reference for the polarity detection. If I were placing odds what's behind this, they'd be on a software bug in the EMS.

[MEXICOWANDERER]

Ductape check any plug-in receptacle tester and you will see fault indicators that will show polarity reversal AND lack of earth simultaneously.

When electricians start treating trees then I will accept Park Rangers knowing **** from Shinola about electrical work.

[Ductape]

OK, I will bite.

IF the ground was open, as reported- then how was the allegedly reversed "polarity" determined?

Think about it.

[time2roll]

WyoTraveler wrote:
Wrong polarity?:h

Standing barefoot in some water and the power is on.... would you prefer to grab the neutral or the hot?

Now what if it was unknowingly reversed?


OK somehow you survive that and you need to replace something in the RV. You turn off power at the breaker and you are safe good-to-go right? Except the park has the power reversed so power is feeding in on the neutral....

[ReneeG]

WILDBILL308 - the exact same thing has happened to us. The park kept trying to say the pole was fine and that it must be our rig, which was not the case. We ran just fine by plugging into our generator. They couldn't fix the problem so instead of moving, they just charged us the dry camping fee and we used our generator as needed for the one night. Then same thing happened at a state park on the same trip and this time they found the problem in the pole.

[MEXICOWANDERER]

Keep it in mind

Reverse polarity

Line voltage enters through neutral. Now go searching through your rig trying to find anything, anything at all to limitt current if any device in your rig fails a neutral earth isolation. A simple loss of earth bonding means your rig gets frame electrified. A bad leakage across neutral to earth means the offending appliance goes up in flames.

Test the plug then plug in. How hard can this be?

The level of intelligenge to RV should not be mandated to meet but not exceed the intelligence level of a six-year-old. Like putting training wheels and seat belt on a trail pony.

[Ozlander]

camperkilgore wrote:
Most of the time reverse polarity plugs present no problem.

Scenario #2: We're using an old trouble light, and the finger accidentally comes in contact with the outside of the metal socket that holds the light bulb in place. The socket is always connected to the neutral wire, so no big deal... unless the trouble light is plugged in to an outlet with reversed polarity. In this case, we'll get a shock. If this happens while we're laying on the garage floor working on a car, there's a good chance that this could be the last shock we ever get. This can also happen with old table lamps that have exposed metal sockets.

Old trouble lights and table lamps can be plugged in either way, so the polarity of the receptacle makes no difference.

[edatlanta]

WILDEBILL308 wrote:
Well my surge protector saved me one more time. Stopped off at Galveston Island State park on the way home from the FMCA 6 state rally in Conroe. Plugged my Surge Guard in and got a reading of Reverse Polarity and bad ground. Called the office and they worked on it for a while then told me it was good. Well the Surge Guard was still giving me the same report. So I ended up moving to s different spot. I am still amazed at how many people tell me they never had a problem and don’t need a Surge Guard or some other protection for their rigs. This reminds me of the old saying “Pay me now or pay me latter” If you don’t have a Surge Guard you may be paying a lot latter.
Bill

I agree completely and WILL NOT plug anywhere without my EMS. I'm so paranoid about bad power that I have a brand new spare one still in the box. It will be put in service when and if the daily use one ever has to go back for warranty service. Expensive spare? Yes, but a whole lot cheaper than what damage could to be done to my 5'er.

[camperkilgore]

Most of the time reverse polarity plugs present no problem.

It's when something a little out of the ordinary happens that presents a hazard.

The normal wiring in appliances is that the hot wire is connected to the switch in the device, and the voltage is removed when the switch is in the off position, but if the plug is reversed the neutral is now switched off and the voltage is still present in the device somewhere. It's always wise to unplug an appliance before tampering with it, but we don't always do that:

Shock hazard scenario #1: We are toasting an english muffin and it gets stuck in the toaster. We look in the toaster and see that the heating elements are off, so we assume it's safe to stick a knife in the toaster to get the muffin. We should be safe doing this, because the switch that controls the flow of electricity to the heating elements in the toaster shuts off the hot wire. Unfortunately, the toaster is plugged in to an outlet with reversed polarity, so the switch on the toaster is shutting off the neutral wire instead of the hot. This means there is always electricity at the heating elements just waiting for some poor sap to stick a knife in, and that electricity will travel up the knife, through his body, and back to the earth. Breakfast ruined. Should have unplugged the toaster, but we have never had a problem before, and we were in a hurry.

Scenario #2: We're using an old trouble light, and the finger accidentally comes in contact with the outside of the metal socket that holds the light bulb in place. The socket is always connected to the neutral wire, so no big deal... unless the trouble light is plugged in to an outlet with reversed polarity. In this case, we'll get a shock. If this happens while we're laying on the garage floor working on a car, there's a good chance that this could be the last shock we ever get. This can also happen with old table lamps that have exposed metal sockets.

These scenarios are courtesy of Reuben Saltzman, Structure Tech Home Inspections in Minnesota.

[Rbertalotto]

What do folks recommend for Surge Guard protection......or are you simply reading the socket with a tester before you plug in?

[ga80486]

Do you have a 50 amp or 30 amp?

Can you use a 50 amp if you're plugged in to a 30 amp or 15 amp outlet with an adaptor?

[WyoTraveler]

WyoTraveler wrote:

GordonThree wrote:
Reversed polarity? Was this an AC or DC circuit?

If he had plugged it in 1/30 of a second sooner all would have been OK. :B Maybe that is why electrician was scratching his head. Open ground? Possible. Wrong polarity?:h

Terminology of wires not terminology of voltage. I will say though I have been RVing since the 60s and never had a problem. I suspect, just guessing, that all of those corrections at the outlets were correct when first wired and then some helpful individual changed out a breaker that had no idea what they were doing.

[WyoTraveler]

GordonThree wrote:
Reversed polarity? Was this an AC or DC circuit?

If he had plugged it in 1/30 of a second sooner all would have been OK. :B Maybe that is why electrician was scratching his head. Open ground? Possible. Wrong polarity?:h