50 Amp Surge Protector

[Maxtar]

I bought a 50 Amp surge protector that plugs into the main RV grounds power box. The lights on the surge protector indicates reverse polarity. Does the connection at the main box have to be fixed to the right polarity in order for the surge protector to work properly?

[wa8yxm]

Golden_HVAC wrote:

wa8yxm wrote:
First: on 50 amps Reverse Polarity should not be possible, OPEN GROUND however is.

Second, There are two different 50 amp surge protectors. On one there are LIGHTS, I do not recommend this one as it is a simply spike suppressor nothing more

The second has an LCD screen, reports voltage, current and error messages, This is the one you want.

I would have to say that anything "Can" happen. When I plugged into a 30 amp reverse polarity plug with my RV, the Trace inverter/charger did not like it - to the tune of $450 in repair costs!

Well, I agree anything CAN happen, I do know of a case or two of reverse polarity on a 50 amp system.. On of those cost Consumer's Power (Jackson, MI) several thousand dollars worth of fried electronics since they reversed it,, but .. As I said, that SHOULD be impossible. (not is, SHOULD BE)

What happens when you reverse polarity on a 50 amp? One leg is 240 volts (That is genuine reverse polarity)

On a 30 amp circuit, it is both very easy and far too common, Simply means you swapped the black and white wires..

IN his case, I do agree it is likely a neutral/ground potential difference he is seeing,, This may or may not indicate a problem.

[ken_white]

winepress wrote:
Not familiar with this protector but I think it is seeing an error on L1 and L2 being in phase.
To get the 100 amp service you have:
L1 50 amp
L2 50 amp
Neutral 50 amp
L1 and L2 together give you 100 amp service.
Normally L1 and L2 are out of phase so neutral never sees more than 50 amp
If L1 and L2 are in the same phase, then neutral could be forced to carry up to 100amps, but is only rated to carry 50 amp. Since neutral is not circuit breaker protected, a potential overload exists. No circuit breaker will trip, but you might smell rubber burning.
The camp worker using a volt meter would not be able to detect any error.

If that's what it is doing, then, that is a very good device indeed.

If the L1 and L2 voltages are in phase the voltage measured across these lines will be zero volts, so this error is easily detected.

The only time I have seen this occur is when the RV site does not really have 50 amp service at the pedestal and has modified an existing 30 amp branch to fit the 50 amp receptacle - same concept of the adapter cable.

If this is what happened, then the breaker will trip when more than 30 amps drawn.

If the main service panel some how had two 50 amp L1 or L2 branches off the same phase bundled together, then yes the neutral could get easily be overloaded.

Having both lines being the same phase should not give an overload condition or the 50 amp - 30 amp adapter cables would never work because the would cause the same fault.

[ReneeG]

larry barnhart wrote:
what I can do is power up the Honda 1000 and plug in my 15 amp battery charger to the plug in as we use to hook the truck and trailer and then use the inverter to make electricity. this has worked very well plus we have a battery charger for other reasons. I am going to make the simple plug as an above post showed. we can have power with out a gen running if we manage what we do. We have 4 batteries

chevman

Good idea.

[larry_barnhart]

what I can do is power up the Honda 1000 and plug in my 15 amp battery charger to the plug in as we use to hook the truck and trailer and then use the inverter to make electricity. this has worked very well plus we have a battery charger for other reasons. I am going to make the simple plug as an above post showed. we can have power with out a gen running if we manage what we do. We have 4 batteries

chevman

[ReneeG]

larry barnhart wrote:

ken white wrote:
Renee, you have a nice set-up but Larry only has a small Honda so he can get by with this ->

Thanks everybody I will do this.

chevman

Chevman, having our generator on hand, when the campground post is faulty, is sure nice. The couple of times this has happened was for overnight stays so we didn't move and they reduced our rate to a dry site rate.

[winepress]

Not familiar with this protector but I think it is seeing an error on L1 and L2 being in phase.
To get the 100 amp service you have:
L1 50 amp
L2 50 amp
Neutral 50 amp
L1 and L2 together give you 100 amp service.
Normally L1 and L2 are out of phase so neutral never sees more than 50 amp
If L1 and L2 are in the same phase, then neutral could be forced to carry up to 100amps, but is only rated to carry 50 amp. Since neutral is not circuit breaker protected, a potential overload exists. No circuit breaker will trip, but you might smell rubber burning.
The camp worker using a volt meter would not be able to detect any error.

If that's what it is doing, then, that is a very good device indeed.

[CA_Traveler]

ken white wrote:

Maxtar wrote:

Old-Biscuit wrote:
50A reverse polarity

Hot to ground.......no 120V but ground to neutral shows 120V

Reverse Polarity condition 50A (ground and hot lines coming into the RV are reversed, or an open conductor)

But I am not hooked up to the RV yet. I only have the surge protector hooked into the outside box and am getting that reading.

It a problem with the pedestal or your surge protector.

X2

I'm reluctant to say what is causing the reverse polarity condition. His surge detector has 2 lights for each line (4 states) vs the common 120V 3 light household analyzer. Fortunately he's not plugged in.

I hope that the pedestal doesn't have a hot connected to the ground as that would mean for anyone plugged in the chassis would have 120V, a very dangerous situation.

[larry_barnhart]

ken white wrote:
Renee, you have a nice set-up but Larry only has a small Honda so he can get by with this ->

Thanks everybody I will do this.

chevman

[ken_white]

Maxtar wrote:

Old-Biscuit wrote:
50A reverse polarity

Hot to ground.......no 120V but ground to neutral shows 120V

Reverse Polarity condition 50A (ground and hot lines coming into the RV are reversed, or an open conductor)

But I am not hooked up to the RV yet. I only have the surge protector hooked into the outside box and am getting that reading.

It a problem with the pedestal or your surge protector.

[Maxtar]

Old-Biscuit wrote:
50A reverse polarity

Hot to ground.......no 120V but ground to neutral shows 120V

Reverse Polarity condition 50A (ground and hot lines coming into the RV are reversed, or an open conductor)

But I am not hooked up to the RV yet. I only have the surge protector hooked into the outside box and am getting that reading.

[ken_white]

Maxtar wrote:

Bumpyroad wrote:
what is "reverse polarity" on a 50 amp outlet? I can see on a 30 amper where the hot and neutral could be reversed, but on a 50 amp outlet if one of the hots was switched with the neutral making the neutral hot, you would have a hot to hot connection???????? wouldn't that be sort of a "mess"?
bumpy

I know, that's what I was thinking. You've got 2 110 amp lines coming off the box, so what difference to which side it is hooked up inside the box make?

It doesn't make a difference when the 2 hot sides are swapped and that will not create a fault...

Hot to neutral will create a polarity fault.

[Maxtar]

Bumpyroad wrote:
what is "reverse polarity" on a 50 amp outlet? I can see on a 30 amper where the hot and neutral could be reversed, but on a 50 amp outlet if one of the hots was switched with the neutral making the neutral hot, you would have a hot to hot connection???????? wouldn't that be sort of a "mess"?
bumpy

I know, that's what I was thinking. You've got 2 110 amp lines coming off the box, so what difference to which side it is hooked up inside the box make?

[ken_white]

Renee, you have a nice set-up but Larry only has a small Honda so he can get by with this ->

[ReneeG]

ken white wrote:

larry barnhart wrote:
thanks for the come back. More than a carpenter can understand. I can do something different for our needs using a Honda invert 1000. thanks again
chevman

Larry, all you need to do is to make a Ground to Neutral connection in a dummy plug, plug it into the spare receptacle, and your generator will work without causing a fault.

Larry and Ken - this is what ours looks like -