Wire issue

[Gregg]

It's not always true that one leg is just for the rear A/C.  In our coach one leg powers front A/C, refrigerator, a bedroom outlet and the water heater.  The other leg powers the rear A/C, inverter/charger, and block heater.  It would be a waste to power just a single A/C unit from a 50A leg when all the A/C draws is 10-15A.

Also thought the same thing which is why I was thinking it might apply to the original post.  The article went into enough detail that helped me finally understand and might help others.  The marking on the plugs and its similarity to the standard dryer plug attributed to the confusion. 

 

[Thehustler]

If the converter box goes bad could that cause part of it to stop working?

 

[Lou Schneider]

If the converter stops working, you'll draw 12 volt power from the house battery instead of getting it from the converter.  Eventually the battery will drain down and you won't have any 12 volt power.

 

[Gary RV_Wizard]

This 220v thing always causes a lot of needless confusion. RV 50A service is 220v/120v, just like residential house service is 220/120v. That few RVs have any 220v appliances onboard doesn't change the fact that 50A service uses a 220v outlet & plug, and has 220v available if needed. An RV designed with a 50A shore power system handles the 220/120v input in whatever fashion suits its needs, which is usually just a pair of 120v/50A power sources.

The confusion is further compounded by stories of major damage from plugging a 30A/120v RV into a 220v outlet. That's an entire different matter.

 

[Thehustler]

So should u put a 50amp service in or just keep the 50amo wall receptical?

 

[eaglestar]

So should u put a 50amp service in or just keep the 50amo wall receptical?

The 50A receptacle is what in the RV world is meant by 50A service. If everything was working before you pulled the genny then your shore power (that 50A receptacle) is OK. As others have stated it sounds like you have lost half of the feed. The common point between the shore cord and the generator is the transfer switch so that's where I would start looking for the problem. Perhaps someone with specific experience with your model MH will see this and be able to offer less general help.

 

[Thehustler]

I have good current from the breaker in garage and I have good current at the breaker n the coach. So I guess I need to find the transfer point? Would that be neat the gen or near the breaker box

 

[John From Detroit]

Ladies and gentelmen.. YOu have confusion

A 50 amp RV outlet, properly wired, is a 240volt outlet (220-240 volt)  So I am guessing when theO/P said " 220 volt (He's older and remembers when that was the satandard same as me) he meant 50 amp.

And no damage was done

Now a 30 amp outlet is 120 volt.

So we have folks saying "I plugged into 120 volt" when they mean 15 amp

Let' stick with amps when we describe outlets and not use voltages save for DO NOT PLUG INTO A 30 amp outlet that is more than 200 VOLTS or damage will occur.

All outlets are rated in AMPS.

 

[Gary RV_Wizard]

If you have "good current" at the breakers in the coach, then the transfer switch is working. But your description said that you don't have any current to the appliances in the rear of the coach, so how can it be "good current"?

The transfer switch is at the point where the genset and shore cord wiring come together, somewhere between the outer wall of the coach and the back of the breaker box.

 

[Thehustler]

I tested the breaker in the house and I tested the cord that goes to the coach and they both have current I dont think I checked the coach breaker box maybe that's where it will b?  The transfer switch what would it look like is it a big box or will it just be a small thing wired in?

 

[Gregg]

Attached is a photo of a transfer switch.  Somewhere I thought you stated that you started the generator and everything worked OK.  If that is accurate, then I would locate the transfer switch and verify incoming shore power.  If that checks out OK, then check on the other side of the relay or transfer switch. Making the assumption that you did not remove any of the wires during your previous work which might be have been reinstalled incorrectly.  That should tell you if you have a problem with the transfer switch.

You stated current.  Assuming you are really measuring voltage.  Current is the amount of flow of electricity and is measured in amperes.  You should be measuring Voltage right now not current.  As previously mentioned, each leg or feed should measure 120V or if you measured across both feeds it should measure 240V on a 50A feed which you previously mentioned that you have.  If you are using a VOM and just placing the probes on the connected wires, then you measuring voltage.  As I stressed before, be very careful because you are dealing with 50A of current.  Touch the wrong thing and it could then become the flow of electricity or current between you and the ground. Show it respect because it can be deadly.

 

[Thehustler]

Ok thanks for the pic I have seen that box. So if everything works from gen but not shore power it's possible that's switch is bad? All I took out was the gen I believe it I just had to unhook the power cord that goes to the coach and a ground and a hot wire so unless I missed something it should all b hooked up. Just think it weird that it all worked last week and when I took gen out Sunday half the motorhome stopped working.  I will check the transfer switch when j get back home. Thanks again for all the help

 

[Gregg]

Agree kind of odd which is why I mentioned testing with generator.  If everything runs OK off of the generator and that is all that you disconnected, then you probably put everything back together properly.  I would double check to make sure.  Hopefully you jotted down the wire colors or took a photo and put everything back as it was.  I find my phone camera can be one of the best tools that I have.

If everything looks good there, then I would still check the shore power feeding the transfer switch.  If you are getting the 240v as expected, then check the backside. If it does not register anything then the switch is probably bad.  Remember, you will only get 240v if measuring across both hot feeds.  Since we know it is working at least partially, you could measure each feed separately and that would let you know which one is bad.  Place one probe on one single feed then the other probe on the ground wire.  It should measure 120v.  If it does not, then that is the bad leg or feed.  Even if you do, I would check the second feed just to make sure you are placing the probe on the correct wires. 

 

[Gregg]

One other thing I was just thinking about....Since you were moving things around, I would unplug the shore power.  Make sure all of the wire connections are tightly seated against the lugs or screws.  It is possible something was loose and now not making a good connection.  If you have a loose connection, it is possible to have power on the lug, but the wire is not getting the current or flow of electricity transferred to it.

 

[Lou Schneider]

Place one probe on one single feed then the other probe on the ground wire.  It should measure 120v.  If it does not, then that is the bad leg or feed.  Even if you do, I would check the second feed just to make sure you are placing the probe on the correct wires. 

Good advice, but measure from each leg to neutral, not ground.  You can measure 120 volts from each hot leg to ground, but if the neutral is bad or missing you'll get wildly different voltages inside the rig.

 

[Gregg]

Good advice, but measure from each leg to neutral, not ground.  You can measure 120 volts from each hot leg to ground, but if the neutral is bad or missing you'll get wildly different voltages inside the rig.

You are absolutely right especially with the fact that newer 50A should offer both compared to some 240v connections.  Since ground and the neutral go back to the same spot within the residential main box, I personally know better but improperly use the term interchangeably.  Thanks for pointing that out.

 

[Gary RV_Wizard]

TheHustler: You seem to want to ignore that there are TWO hot wires in a 50A outlet, TWO pins in the plug that carry current & voltage, and TWO connections to the transfer switch.  Your shore power may be fine ( or not), but until you can verify that BOTH the hot wires are working, we will continue to flagellate with no progress. This sort of problem takes a lot of attention to detail, i.e. specific measurements in specific places, in order to isolate the cause.

 

[Gregg]

Gary I can tell you have been at this helping people for awhile.  For many we have a tendency to skim over details that should be conveyed.  Let me take a stab at the details but please read through and see if I missed something in the following. 

If I was trying to to track this down I would do the following:

By referencing the attached images: You need to understand and remember Feed or hot wires and neutral along with the colors associated with each.  In the examples supplied, the feeds or hot wires would be Y and X.  The Neutral is the W.  Take a look at the attached wire image for an example of the color schemes but you may have a green wire instead of the bare copper.  Remember the colors.
Steps:
1) Test Shore Power at the shore power receptacle. Check voltage by placing VOM probes into each feed line.  It should read 240 volts.  Using the example that would be Y and X.
2) I would then check to make sure the Neutral is also working or connected properly.  To do that, place one probe in one feed lets first test Y, then place other probe on the Neutral or W listed on the image.  You should get 110v to 120v.  If that is true, keep the one probe in the neutral but move the other probe currently in Y and place it in the second feed X.  If everything checks out and continues to get around 110v, proceed to the next step.
3) I would then test the feeds going into the transfer switch.  Now here is where knowing the wire colors will be helpful. Test that you are still getting 240v by placing the probes on the two feed wires (X and Y).  I would again test each feed (Y, X) individually with the neutral (W) to make sure you are still getting the proper 110v reading.  That would be (Y and W) getting 110v. Then (X and W) again getting 110v. If everything continues to work as expected, proceed to step #4.
4) Perform the step outline in #3 on the opposite side of the transfer switch.  If everything continues to read properly, I would then open and test the RV breaker box.

Based on the fact that everything works properly when running the generator, I would be willing to bet you will have isolated your problem at this point.  Before going through all of this, I would reiterate my previous post and make sure all of the lugs or screws are tight and you do not have any loose wires.  Before sticking a screwdriver in there, make sure you unplug or turn off the shore power.  If anything felt the least bit loose, I would turn the shore power back on and go into your RV to verify you still are experiencing a problem.  It may have been as simple as a loose wire.

 

[Just Lou]

This is one of the most confusing and disjointed discussions I've seen on here in some time.

I know the OP said he put the generator back in, but I can't find where he said it now works, yet no one has asked.  ???    Assumptions abound.

No one has asked what the OP means by his reference to a "Chassis switch", or a "Chassis Light". :-\ ???

 

[Gregg]

A number of us suggested and referred that if everything worked off of the generator and the  OP reply in post #31 "So if everything works from gen but not shore power it's possible that's switch is bad?"  Hope the OP would have thrown up red flags then or you are absolutely right we missed a very important bit of information.  Although ruling out shore power problems still makes sense to me and probably where I would have started.