Fried electrical

Help!  I received bad advice and wired my 30amp plug with two hots and one ground.  When I plugged it in the GFI tripped on the electrical plug in the power bay under the motorhome.  I have since wired a new plug using the 50amp cord.  Output power is correct with two hots, one neutral and one ground.  I have absolutely  no power in motorhome.  Generator causes the power switch to trip the contact points.  Still no power in motorhome.  Shore power I have to push the switch in.  Still no power at the circuit breaker panel.  I have checked all the GFI plugs that I can find.  When 50 amp cord is plugged into the receptacle on the motorhome I need to physically push it in and hold it for the power to get to the power switch.  I have the correct power on front end of contacts.  I have the correct power on the back end when I push in the switch.  Still now power to the circuit breaker panel in the bedroom of the coach.  The coach is a 1994 Safari.  In the power bay I have a power switch that has the generator, inverter, and shore power in.  It is also hooked up to a power surge box.  There is a GFI plug in the bay with a large plug plugged into it.  Inverter will now even power the television.  The inverter hums like it is working.  I believe I need at least a new power switch box (two contact points, and two circuit boards in the box), I don't know if I fried the power surge box.  I will have to look at the receptacle where the shore power hooks into the motorhome (probably some issues there).  Any idea why no power to the circuit breaker.  Is there another fuse, relay, or circuit breaker between power switch box and circuit breaker panel?  Any help would be greatly appreciated.

May have fried your automatic transfer switch. It switches power from shore or generator and all power goes through it. Onboard GFCI will not usually effect shore power.

What exactly are you trying to accomplish here, simply replace a cord and plugs?? You stated you had mis-wired your 30 amp plug

You mentioned using a 50 amp cord and plugs?? Are you using a 50 amp source (your description sounds like it). Are you sure you have a motorhome that is wired for 50amps?? I don't remember that as being widely used around the year 1994 .

Not familiar with a 94 but start with this site here: http://www.myrv.us/electric/
check your 30a (& 50a if you have that) wiring plug(s) to make sure it is correct. Once you know you have correct shore power then see if you have an auto transfer switch as that will be next in line before the MH breaker panel. Once you get power to the panel then you can start tracing what works & don't work in the MH depending on what you have.

I suspect he fried more than his cord. He likely did in such diverse things as televisions, microwave, converter, and possibly the electric elements on the water heater and fridge.. If he had an Air conditioner operating it may have fried as well.

This is why I recommend folks install a 50 amp outlet for an RV (Even if they only use 30 amp breakers) and use the proper adapter.. This completly avoids this kind of OPPS.

Got to agree with John on  this one.  His scheme is foolproof.
I have done a LOT of troubleshooting over many years, and one thing I learned was that when  all the facts are presented, & everything looks perfect, but the damn thing don't work, likely one of the 'facts' is  wrong, or you need to ignore one or  more of the facts in your analysis.

Thanks for the answers to my post.  I originally wired a 30 amp receptacle.  Long story but I built a metal building to house my motorhome.  I was given advice from Home Depot on how to run electrical (30 amps) from my main power pole (that feeds a circuit breaker panel on my house) and the new metal building with its own circuit breaker panel.  I was told to run just three wires.  Later they told me I should have run 4 wires (two hot, a neutral, and a ground).  I then used a two pole circuit breaker on the power pole and a two pole circuit breaker in the new circuit breaker panel.  The 30 amp receptacle was wired with two hots and a ground (per instructions from home depot "expert".  Apparently 220 volts went into the motorhome.  I have since wired a 50 amp receptacle with the two hots, a neutral, and a ground (correctly) as John suggested with 30 amp circuit breaker but with a 50 amp cord and plug.  When I plugged it in there wasn't anything electrical applicance on ( no tv, ac, fridge, washer/dryer, etc)  Everything was off.  Just didn't have anything coming on (the light on the AC light switch, etc).  To answer Alfa38user.  I am wired for 50 amp service.  I have been plugged in many times at campgrounds to 50 amp service.  To answer Wizard46.  Yes I do think I need a new transfer switch.  Just worried why no power at the circuit breaker in the coach when I push transfer switch (contacts) in and am receiving power on the outbound side of transfer switch.  What is between the transfer switch and the circuit breaker.  By the way when the power was plugged in originally with the 220 volts, none of the circuit breakers tripped in the coach.  I also have a power surge hooked up to the transfer switch.  Isn't this supposed to guard against errant voltages such as this?

Depending on what model of "surge protector" you have, it may have prevented the over-voltage from doing damage. And in doing so it may have sacrificed itself, so you might try removing or bypassing that to see if you get power. But not all surge devices have voltage monitoring - what make and model do you have?

No matter how you did it, wiring two hot wires into a 30A outlet pretty much guarantees you put 220v where only 120v should ever be. Breakers won't trip due to over-voltage - only excessive current will do that. But the over-voltage can still fry electrical components. Chances are good that one of the things fried is a relay or two in the transfer switch.

I'm unclear on what you have to "push and hold in" to get 50A shore power, especially since you say you have no shore power anyway. What is it you are holding in, and how/where are you detecting that you have power when holding it in?

Gary,

I'm pushing in the switch inside the power transfer switch causing the contacts to come together.  When I turn on the generator the contact hooked to the generator will pull itself together.  The shore power contact will not.  I'm at work now but I think I remember seeing something like Liebert on the surge protector.  I use a voltage meter to see the power before the contact switch and then when I push and hold the switch in I use the volt meter on the "power out" side to verify I have voltage.

Reading the OPs last post, running three wires from the pole to the new subpanel in the metal building was OK.  A local ground from the new subpanel was needed to be in compliance with the electrical codes.  The 2 circuit breakers at the pole isolates the subpanel; then 2 circuit breakers in the subpanel isolates the receptacle.  Hopefully this is the configuration. 

Here is what I surmize occurred from the original post: in order to adapt the 30a receptacle to the MH 50a cord, the OP must have used a 50a [L1, L2, N, & G] female to a 30a [L1, N, & G] male adaptor.  The adaptor (typically a 1-120v) input [L1] with a neutral [N] and a ground [G] put 2-120v feeds on L1 & N into the adaptor causing a dead short in the female end.  All of the breakers and wiring should have been checked.  Assuming that everything is satisfactory between the pole and subpanel there should be power to the 50a receptacle.

It is pretty hard to follow the OP second post.  Understanding the power input configuration is important in order to help in troubleshooting.  Is the output of the subpanel a female receptacle or wiring with a male plug?  Is the surge protector in line between the transfer switch and the MH breaker panel? or somewhere else.  My surge protector has a time delay (~2min) prior to powering the MH.  Is the OP waiting long enough before checking power at the MH circuit breaker panel?  I'll subscribe to this post in order to aid the OP.  Just my two cents...

I use a voltage meter to see the power before the contact switch and then when I push and hold the switch in I use the volt meter on the "power out" side to verify I have voltage.

Click to expand...

Not sure I understand the "push the button in" conclusions  either. The contacts in the transfer switch should be transfer contacts and the relay operates only when the generator puts out power and switches the output from outside power  to generator power. The pair of contacts that are closed when relay is not operated should transfer power on the cord toward the surge protector and/or the power panel, depending on how the RV was wired as stated by teddyu.  If this is the case, pushing the button opens one set and and closes the other set of  contacts manually, as the OP seems to be describing, simulating the action taken when the generator is functioning, no power out would be the normal condition as the generator was not actually running. If power is found on the input from the cord connection and no power is observed on the output (without pushing the button) then the break contacts have failed. A new transfer switch is needed.

The only way to resolve this is, as teddyu said, is to first determine how the wiring is really arranged in this RV and then go through the system right from the power connection, step by step, using a meter to determine where the failure is.

Jumping into the middle where there may be multiple problems seldom works very well in my (40+ yrs electro-mechanical) experience. My feeling is that there are going to be several failures found along the way (and $$$ maybe).

If I'm reading the OP's post right, he wired a 30 amp rv outlet with two hots and a ground (240 instead of 120) he then plugged his 50 amp mh cord into it using a 50 to 30 amp adapter (I guess). If that is what he did he would have had 240 volts on both legs of his mh panel and as has been mentioned, anything that was on that had to do with electronics or motors could have taken a hit.

pilotguy25 said:

Gary,

I'm pushing in the switch inside the power transfer switch causing the contacts to come together.  When I turn on the generator the contact hooked to the generator will pull itself together.

Click to expand...

That tells me a whole lot..  There are basically 2 types of Automatic Transfer Switches.. The one I have senses generator power and if it sees it a set of Double Throw contactors pulls in and transfers me to Generator power.

But if it does not see generator power these contactors (Relays) drop out to their "At rest" position and feed shore power  There is no sensor for shore power at all, that is the relay default (The system default is generator, confusing yes, but really simple).

The other type of system, which you have, may actually be better for assorted reasons.. And then again it might not.

It senses shore power, and if present it waits a short period for you to get the plug all the way into the outlet, then it goes CLUNK and pulls in the "SHORE" contactors, which are likely Single Throw.

If it senses generator it first drops shore power out, then pulls in the Generator contactors.

Much more complex than mine.

When you plugged into 220 volts.. You blew the 120 volt sensors in the ATS.

It needs a new circuit board.

What we also don't know is how the 30a receptacle was wired.  I'm assuming that a receptacle that is wired in a \ | / configuration: the center blade is subpanel ground [SP-G] and both the \ & / were powered from the subpanel [SP-L1 & SP-L2].  I'm assuming this since ONLY THREE wires were connected, not four.  Let me clarify my last post.  In that configuration, the short would have been 120v [SP-L2] to ground [SP-G], since MH-L1 & MH-L2 are normally powered by SP-L1 for 1-120v 30a feed.  When applying power from SP-L2 to either the Ground [MH-G] or Neutral [MH-N], using a female 50a to male 30a adaptor, a direct short to subpanel ground occured from SP-L2 and at least one breaker somewhere tripped.  If the center blade of the 30a receptacle was powered [SP-L1 to MH-G] and \ or / was powered [SP-L2 to MH-N], 240v was shorted by the MH [MH-N to MH-G] in one of the devices (circuit breaker panel, surge suppressor, or transfer switch) and at least 2 breakers should have tripped.  No mention of that by the OP.  Also, 240v could have been monentarily applied to the MH-L1 and MH-L2 via the MH-G/MH-N connection; MH-L1 and MH-L2 becoming the Neutral/Ground for the system. What kind of havoc would that cause is questionable.  This last scenerio probably did not occur, since power would have been applied to the generator ground/neutral and sould have fried the generator.  But the OP stated the generator pulled in the transfer switch.  My opinion is: I don't think there is any power coming from the subpanel or any of the MH-L1, MH-L2, MH-N, MH-G are open in the cable, plug, any connection point or combinations of conection points.  The OP should test for 120V [SP-L1 & SP-L2] to SP-G and SP-N and 240v SP-L1 to SP-L2.  If this is good, plug in the MH and check for the same conditions at the next device, etc. Just my two cents... 

However it was connected is kind of unimportant, except perhaps as a post mortem discussion now since all that has been undone by the OP and replaced with what seems to be the correct stuff. I believe he wants and requires a normal 50 amp connection that works and powers his RV. What remains is to isolate and determine what he blew up with the bad connections made originally. Checking voltages as suggested is part of the second step in this process (and must be carried out to avoid blowing up anything else). Understanding the layout and wiring in this particular RV should be the first step.

Let me clarify my last post.  In that configuration, the short would have been 120v [SP-L2] to ground [SP-G], since MH-L1 & MH-L2 are normally powered by SP-L1 for 1-120v 30a feed.

Click to expand...

But an RV is not supposed to have neutral and ground bonded together - it's a subpanel in the campground's distribution system and neutral to ground bonding only happens at the main service panel.

It's more likely the 220 volts shorted the surge suppression element(s) in the surge suppressor, tripping the breakers.

I'm pretty sure that my RV's Neutral and Ground are tied together like a house main service panel in the breaker panel, but I'll check. 

My GFCIs trip while powered by the generator.  The GFCI is tested by inserting a ground causing the sensing unit to sense a fault current.  I don't see how the differential fault current would be sensed if the GFCI ground attached to the chassis floated above the generator.  There would be no current flow unless the generator circuit neutral and ground are tied together.  What would be the sensed current?  I'll check on this also.

My ATS is a power-seeking generator-preferred, fails to last position transfer switch.  Just my two cents...

teddyu said:

I'm pretty sure that my RV's Neutral and Ground are tied together like a house main service panel in the breaker panel, but I'll check. 

Click to expand...

Years ago I understand that was, in fact, done.. These RV's will trip a 20 amp outlet (And they were 20 amp trailers by the way)

CODE, today (And for the last several years if not decades) is to NOT do it that way.. I know for a fact the neutral bus in my rig is isolated.  No common connection unless.... and this is a part time and only partial unless.

IF (As I am doing now) I'm running on batteries, THEN the inverter powered circuits are bonded.. If I'm running on shore power that bond is broken .

My ATS is a power-seeking generator-preferred, fails to last position transfer switch.

Click to expand...

Translation???

Afla38User,

The transfer switch looks for power (does not move to that position unless power is available), fails to last position (if in generator supply position, stays in generator supply position with no power available at shore or generator power) and prefers the generator over the shore power if both are available. 

Checked my coach, the 120/240v ground and and neutral are split in the coach, while the generator 120v ground and neutral are tied together prior to the transfer switch.  Just my two cents...