Getting shocked on the copper plumbing.

[stanwilder]

With farther testing I’m finding that I’m getting shocked at the back storage hatch while looking for the location of a heavy grounding single copper wire.
Since I think I’ve had about every possible configuration of working through the Airstream Power panel, I’ve gone ahead and posted some pictures of the Power Panel information plate (2 Pictures) and pictures of the actual wiring in the breaker panel. (2 Pictures).
Your comments and suggestions are important to me at this time since I’m getting a new A/C late next week and I don’t want to damage it with LOW Voltage.
The links to the pictures is here:
http://www.ceramteck.com/airstream/DSCN0299.jpg

http://www.ceramteck.com/airstream/DSCN0300.jpg

http://www.ceramteck.com/airstream/DSCN0302.jpg

http://www.ceramteck.com/airstream/DSCN0303.jpg

Possible there is supposed to be a jumper wire between the GREEN GROUND and the Neutral and Grounding bars.


Stan Wilder
Dallas TX

76 Airstream

[azflycaster]

Stop what you are doing and unplug the trailer from city power now!

The breaker box you have is not correct. You have a 240 2 phase box connected to 120 volt single phase. Your neutral (white) is feeding at least one of the breakers and you have no voltage return trough the neutral. All of the return voltage is being forced through the ground and the shell of your trailer is most likely hot.

You have a very serious and dangerous problem and you are exposing yourself to lethal voltages.

You need to get the correct breaker box with a single hot bus to feed all of the breakers (black wire). It should have neutral bus that connects to the white wire and a ground bus that connect to the green wire. The neutral and ground should not be tied together.

Sorry to be so blunt about the problem, but this is very serious.

[markdoane]

Stan,

I'm sorry but your breaker panel is totally whack. You need to start over.

First of all, it's hard to tell which is the feed line coming into the box from the 30 amp feed cable, but it should be going into the bottom of the 30a breaker on the far left. What is hooked up there appears to be solid conductor, so it's not the shore power cable.

What does appear to be the shore cable is hooked up to one of the main lugs, and the neutral is hooked to the other lug. This is wrong. The black wire should be attached to the bottom of the 30 amp breaker. The white wire should go to the neutral bar. And disconnect the green ground wire from the neutral bar.

Remove the lower ground bar (with 7 screws) that's attached to the neutral bar (5 screws). Mount it separately and isolated from the neutral bar. They must not be connected.

You can mount a jumper between the two main lugs where the black and white wires are connected. Then you will have 120v power to both the buss bars being fed from the 30 amp breaker.

Separate all the ground wires and the neutral wires to their appropriate bars and you should be in bussiness.

I have no idea how your wiring got so far out of whack. It appears to have been done by someone trying to duplicate the wiring in a house, which is different than an RV.

Post some more pictures before you hook up the AC.

[garry]

Hard to guess on electrical stuff without a meter and while I have wired a few houses I'm not a certified electrician and since you have not had a response from the experts.

My guess; I can't tell from the pictures but it looks like you main power cord is 3 wire black, white and green with a bare ground fished in from somewhere.

It looks as if you might have a hot "black", hot "white", green "neutral and "bare" ground set up for 50 amp service (4 prong plug).

If 30 amp you would have hot "black, "white" neutral and bare ground and a 3 prong plug.

Regardless ground & neutral should "not" be tied together, an RV is like a sub panel and ground and neutral are only tied together at the source (CG main panel or if plugged in at home your main panel in the house).

I can't tell with out a meter how the bus bar is run but if set up for 30 amp service I'm wondering if the hot & neutral might be reversed.

So for starters is this the factory wiring ?

Garry

[garry]

I see the experts did jump in while I was typing up my response.

Looks as if we all agree whatever it is it ain't right and could be very dangerous.

Garry

[darlingbooks]

This service panel/distribution board breaker/box is suitable for use as service entrance equipment when installed in accordance with the N.E.C.

This box has no main cutout breaker, it wasn’t designed for one, and has only the single breakers.

I cannot attest to the use of this box in this application, as it might need a main breaker at the power source feeding it.

The wiring diagram shows a connection between the green ground connecting block and the neutral connecting block. If this connection was removed, and if the ground connection in your power cable is bad/broken, you can get shocked.

The white stranded wire is terminated on the alternate post, and is serving as an additional 110VAC source, and only feeds AC to breakers 1&2 and 5&6

The stranded white wire has the strands splayed before they enter the terminal, and this may be a problem.

Using a multi-meter, and with the shore power cable attached, measure the chassis frame to a known good earth ground, and if you measure any voltage present, disconnect the power from the trailer, and troubleshoot with the multi-meter. If this is beyond your skills, get help.

I would hope that you have not been wiring the shore power end of your cable to 220VAC.

Good luck
Steve

[stanwilder]

In resopnse;
1) I'm the one that installed the shore power to my main building breaker box. I'm absolutelly shure it's 120v and not more. It only tests at 120V at the 25AMP incoming cable.
2) Installing a new breaker box looks like my best solution. I can get this done. When I have my trailer in for the new A/C installation next week.
3) In reply to "Is this factory wiring?", I do not think so. It does not fit the description in the owners manual of having a 30AMP main breaker. It has always been suspect as a "Rube Goldberg" to have 220 V at an add on A/C power plug that supplied an A/C unit that was installed through the front window opening and an add on receptical for a MicroWave owen.
4) Whatever I've got was working fine when the trailer was used as Residential for 3 years. I never new the electrician that direct wired the trailer to the meter pole had made changes.
5) I'd love to see a picture of an AUTHENTIC 70s Airstream power panel.
Thanks to all of you Airstreamers that took my inquiry seriously and offered advise.
I reaspect your investment in time and effort to assist me.

Stan Wilder
214-622-3148
76 Airstream Dallas TX.

[markdoane]

Stan,

Really, this is all you need to do:

1. Remove the solid wire from the bottom of the 30a breaker (far left)
2. Remove the black stranded wire from the center lug and attach it to the bottom of the 30a main breaker. This feeds 120v power from the shore power cable to the buss bar (slots 3,4, and 7,8). It looks backwards, but thats how it's done.
3. Remove the green stranded wire from the far left lug. Buy a separate grounding bar (they are available at any home store), mount it inside the box, and attach the green stranded ground wire and all the bare ground wires to that bar.
4. Attach the white stranded wire to the far left lug, which is the neutral bar. Attach all the white wires to that bar. Don't make any connection between the neutral bar and the new ground bar. They are not bonded in a trailer they way they are in your house.
5. Attach a short #10 jumper wire between the center and right hand main lugs. This will feed power to the other breaker slots (#1,2, and 5,6).
6. Remove the ugly bare copper ground wire. It is not needed or legal.
7. buy a couple of breakers for slots 4 and 5. One will be for the black solid wire you took off of the 30 amp breaker, the other will be for your new AC.

[azflycaster]

Originally Posted by markdoane

Stan,

Really, this is all you need to do:

1. Remove the solid wire from the bottom of the 30a breaker (far left)
2. Remove the black stranded wire from the center lug and attach it to the bottom of the 30a main breaker. This feeds 120v power from the shore power cable to the buss bar (slots 3,4, and 7,8). It looks back wards, but thats how it's done.
3. Remove the green stranded wire from the far left lug. Buy a separate grounding bar (they are available at any home store), mount it inside the box, and attach the green stranded ground wire and all the bare ground wires to that bar.
4. Attach the white stranded wire to the far left lug, which is the neutral bar. Attach all the white wires to that bar. Don't make any connection between the neutral bar and the new ground bar. They are not bonded in a trailer they way they are in your house.
5. Attach a short #10 jumper wire between the center and right hand main lugs. This will feed power to the other breaker slots (#1,2, and 5,6).
6. Remove the ugly bare copper ground wire. It is not needed or legal.
7. buy a couple of breakers for slots 4 and 5. One will be for the black solid wire you took off of the 30 amp breaker, the other will be for you new AC.

This will work, but I personally would replace the box. It will be a lot cleaner and any one in the future who needed to troubleshoot a problem would not have to figure out what alterations were made.

In step 2 you would be feeding the "main" backwards. I've never done this before and I'm sure it might work, but it does present a dangerous situation when servicing the box. That is, the output of breaker #1 would be hot even if the breaker was tripped. From what I see, this would only feed breakers 2, 5 and 6.

The jumper in step 5 would then feed breakers 3, 4, 7 and 8.

[markdoane]

Originally Posted by azflycaster

. . . In step 2 you would be feeding the "main" backwards. I've never done this before and I'm sure it might work, but it does present a dangerous situation when servicing the box. That is, the output of breaker #1 would be hot even if the breaker was tripped. From what I see, this would only feed breakers 2, 5 and 6.

The jumper in step 5 would then feed breakers 3, 4, 7 and 8.

Richard,

Thats right, I have mis-numbered the breakers. Using #1 as the feed would power #2, 5, and 6. The jumper would then take care of 3, 4, 7, 8. Thanks.

The output of #1 would be hot, even with the breaker turned off. But the output is really the power coming in from the shore cable. I know it's backwards from the normal 'direction of flow', but it's been done that way for years.

[darlingbooks]

Before the stranded white wire is moved to a bus bar, we must discover what it is attached to outside of the trailer. The placement of the stranded white wire says that it is an alternate power feed, but it is not marked by tape to indicate so. Please check the 30amp plug outside of the trailer to make sure that it is not energized as an alternate power feed.

Back Feed Mains are allowable by the NEC, but the circuit breaker must be listed and labeled for the reverse feed application, and there are requirements for additional mechanical connection of the breaker to the panel. The breaker needs to be fastened down to prevent unseating while under load. The breaker must not be wired in reverse of the line and load labeling.

The schematic shows that both bus bars are tied together, ground & neutral.

Steve

[markdoane]

Originally Posted by darlingbooks

Before the stranded white wire is moved to a bus bar, we must discover what it is attached to outside of the trailer. The placement of the stranded white wire says that it is an alternate power feed, but it is not marked by tape to indicate so. Please check the 30amp plug outside of the trailer to make sure that it is not energized as an alternate power feed.

Steve

I read the schematic a little differently. To me, the dotted lines to the right of the main lugs read "Alternate Line Entrance", and don't indicate that the three lines are the "Alternate" the "Line" and the "Entrance" wires. So the right hand lug is not an alternate power feed. The alternate line entrance would be the knockout at the bottom of the panel.

Also, the connection between the neutral and the ground bars are labelled "ground when required", meaning the ground to neutral connection is only there when required, for example if it is a separately grounded equipment service panel. All main lugs panels are set up that way, with neutral and ground bars that can be either bonded or not depending on application.

[bibbs]

Ok OK there is nothing wrong with that panel box just needs a little re wiring. the #8 bare copper is a bonding wire it grounds the shell of the trailer,through the green wire to the shore power ground! That should stay connected. to the ground bar.The white conductor, "neutral" floats It only connects to other white wires. You might be able to isolate it from the ground bar by cuting a link. You should not get any voltage reading between white and ground [green or bare] You should get a reeding of 120V between the black to white and black to ground .yeah back feed a 30 amp cb for a main.they work both ways.Just jump the two big lugs to light up all the circuits.

[thecatsandi]

Originally Posted by stanwilder

[deleted]
Thanks to all of you Airstreamers that took my inquiry seriously and offered advise.
I reaspect your investment in time and effort to assist me.

Stan Wilder
214-622-3148
76 Airstream Dallas TX.

I have only one thing to add to this discussion. You new box should be metal. Not plastic. Your current box is rated as an outdoor enclosure. Is it exposed to the elements?
The box is definately wired wrong for 120VAC operation. The work of someone who did not know what they were doing.
PS remove your phone number from your signature. It will get indexed by google.

[garry]

As stated earlier the breaker box should be removed and a standard box with a 30 amp main breaker installed. A new breaker box and breakers will not be very expensive.

I think we all agree this box is not really suitable for RV use. Yes, if you know what you are doing you can wire it to work and the previous owner seems to have wired it for 240/120 operation and ran 2 air conditioners but if it were mine and what I recommend is for Stan to replace the box and wire the new one correctly with a caution not to wire ground and neutral together.

Garry

[stanwilder]

I'll be replacing the box tomorrow.
Thanks for all the greart advise and comments.

Stan Wilder
1976 Airstream

[klattu]

Just got inside from looking at my '89 MH box, almost same as yours in design.
I don't see need to replace, just correct wiring.
I was looking to split my power to rear air to a dedicated plug for dual air at campground and just happened to study wiring in this box to understand.
Mine is stock, and here is your photo with changes needed to be as mine is.
Remove white wire N1 and place over where G1 is now.
Move G1 to the grounding strip.
Place a jumper between the two power supply blocks, as the blue wire shows.
The black wire is correct.

Squint your eyes, and plug it in.

[stanwilder]

The problem is resolved.
I installed a new breaker box and greonded it to the copper pipe with the heavy ground wire.
Power to all outlets, water heater works too, the auxillary plug for the microwave is hot and everything works fine with very little voltage drop when the A/C starts up.

Thanks for all the help.

PS A couple of contributors got it righ on -- as how I could continue to use the old box. IE Jumper wire, add grounding bar etc.

Stan Wilder

[thecatsandi]

Originally Posted by stanwilder

The problem is resolved.
I installed a new breaker box and greonded it to the copper pipe with the heavy ground wire.
Power to all outlets, water heater works too, the auxillary plug for the microwave is hot and everything works fine with very little voltage drop when the A/C starts up.

Thanks for all the help.

PS A couple of contributors got it righ on -- as how I could continue to use the old box. IE Jumper wire, add grounding bar etc.

Stan Wilder

I am still wondering where the main feed hot is coming in. Mine goes to the 30A breaker and back feeds the bus.

[markdoane]

I'm wondering also.

Maybe the reason Klattu doesn't have a backfed main breaker is (perhaps) he has a MH, and the main breaker is over there with the automatic transfer switch?

Otherwise, if you have more than two breakers you need a main disconnect and breaker.