50 amp system, 30 amp supply Does battery continue to charge?

[ByronD]

Our 50 system is connected to 30 amp supply and the slides will not retract. I am thinking that the battery must not be fully charged due to the lower supply amps. I tried hooking the truck batteries with a jumper cable, no help. Anyone have any ideas. Guess I will have to bite the bullet and get an electrician out to up the connection to 50 amp...is that my only option? Thanks in advance for any advise...ByronD

[camper33]

It should not matter if you are on 50 or 30 amp hookup. The converter which charges the batteries runs on 120 volts and draws about 8 amps. I would look for a tripped breaker near the battery. Also check and make sure your battery disconnect switch, if so equipped is on.

[shortlance]

Yes the battery will charge on a 30 amp service with no problem.If you are on shore power--even 30 amp--your slides should work even if the battery was dead. Shore power will supply the 12 volt system. Check your 12 volt fuses. We have run our 5er on 30 amp. many times. You just have to manage your power use if you are running on 30 amp.
I know just enough about electric systems to be dangerous but the shore power will power all your 12 volt systems.

[steelheadbluesman]

You've gotten some good info. Is everything else working? If so, then the problem is isolated to the slide, probably has nothing to do with your power source/amp level, and is most likely a fuse fail. I would check out ALL my fuses, and then check the switch, and tighten any connections you can see, before calling in an electrician. Welcome to the forum!

[FDNYdave]

Originally Posted by shortlance

Yes the battery will charge on a 30 amp service with no problem.If you are on shore power--even 30 amp--your slides should work even if the battery was dead. Shore power will supply the 12 volt system. Check your 12 volt fuses. We have run our 5er on 30 amp. many times. You just have to manage your power use if you are running on 30 amp.
I know just enough about electric systems to be dangerous but the shore power will power all your 12 volt systems.

A 50 Amp service/RV is 240v when you plug it into a 30 AMP service(120) volts only half of your AC electrical system is energized it's possible ( probable)that the nonfunction systems are on that half of your system that's not energized.
Plugging a 30 AMP RV into a 50 amp pedestal is is a lot more straight foward then pluging a 50 amp RV into a 30 amp pedestal

[The Driver]

Hoo boy, my 50amp supplies are always 120 volt, and my coach handles 30amp service on all its circuits just fine!

[steelheadbluesman]

Originally Posted by FDNYdave

A 50 Amp service/RV is 240v when you plug it into a 30 AMP service(120) volts only half of your AC electrical system is energized it's possible ( probable)that the nonfunction systems are on that half of your system that's not energized.
Plugging a 30 AMP RV into a 50 amp pedestal is is a lot more straight foward then pluging a 50 amp RV into a 30 amp pedestal

Hmmm.... Not so sure. My rig is 50A, and everything in my rig works on a 30A pedestal, except the usual 30A issues of my second AC compressor and, of course, any overloads from too many appliances tripping a breaker (which has never happened, and I've had this rig five years.) Otherwise, it should all be working.

[shortlance]

Originally Posted by FDNYdave

A 50 Amp service/RV is 240v when you plug it into a 30 AMP service(120) volts only half of your AC electrical system is energized it's possible ( probable)that the nonfunction systems are on that half of your system that's not energized.
Plugging a 30 AMP RV into a 50 amp pedestal is is a lot more straight foward then pluging a 50 amp RV into a 30 amp pedestal

That statement is totally wrong! 50 amp RV service is two 120 volt lines on seprate legs in the breaker box in the RV.. There is no 240 volt service involved in RV hookup. Basically you have two 50 amp feeds where on a 30 amp service all you have is 30 amp on only one line. Your whole electric system will energize on 30 amp service.

[MickBrennan]

Is the ignition switch in the off position? Just saying.

[camper33]

Some units have a safety interlock switch that has to be turned on to activate the slides. It is usually near the main slide out switch. Again check the breakers near the battery, they are usually auto reset, but they fail. Use a test light to see if you have power on both sides of the breaker. If your slides are hydraulic, you should have a good battery on the trailer, as the pump will draw between 50 and 100 amps depending on the type of pump.

[FDNYdave]

Originally Posted by shortlance

That statement is totally wrong! 50 amp RV service is two 120 volt lines on seprate legs in the breaker box in the RV.. There is no 240 volt service involved in RV hookup. Basically you have two 50 amp feeds where on a 30 amp service all you have is 30 amp on only one line. Your whole electric system will energize on 30 amp service.

50 Amp Service vs. 30 Amp Service

So why can we run so many appliances at the same time with 50 amp service when we were more limited at 30 amp service?
Well, using our equation above - Watts = Volts X Amps - at 120 volts, 50 amps produces 6,000 watts as opposed to 30 amps which produces 3,600 watts. Quite a difference. Ah, but there is more to the story.
Remember at the beginning when we talked about a 30-amp power cord having 3 prongs? Well, those three prongs correspond to a hot 120-volt wire, a ground wire, and a neutral wire.
But the 50-amp power cord has 4 prongs. Those four prongs correspond to a ground wire, a neutral wire, and 2 120-volt hot wires!
So, going back to our equation - Watts = Volts X Amps - we have 2 50-amp lines at 120 volts each. We have two lines capable of 6,000 watts each, not just one. Our total is now 12,000 watts of potential power for 50-amp service as opposed to only 3,600 watts for 30-amp service. Now you can see why 50-amp service gives us so much more capability than 30-amp service.
Another note on 50-amp service. Almost all RVs are wired such that the two 50-amp, 120-volt lines are used separately. In other words, some of the appliances are wired to one hot leg of the 50-amp service and the remaining appliances are wired to the other hot leg of the 50-amp service.
And now we also know why there are two 50-amp breaker switches shown on our pedestals - one for each hot line. But even though there are two switches marked "50", they do not operate independently. The whole circuit will trip if one line is overloaded.
Finally, this is another good reason to have a 50-amp surge protector with voltage protection on your 50-amp rig. Those devices test both lines of the 50-amp service and protect all your appliances no matter which leg they may be on. If you do not have one of these devices, one bad leg could be the reason some appliances work and others don't. However, one bad leg will probably lead to much worse problems than that.
The neutral in a 50-amp circuit is there to help balance the total 240 volts between the two hot lines so they each carry only 120 volts and no more.

so wether or not you use the two 120v legs to created 240v in your rig the pedestal is essentially a 240v panel as pointed out above every other breaker in your panel uses a different 120v leg therefore with only one 120 volt leg half of your breakers will not be powered

[shortlance]

Originally Posted by FDNYdave

50 Amp Service vs. 30 Amp Service

So why can we run so many appliances at the same time with 50 amp service when we were more limited at 30 amp service?
Well, using our equation above - Watts = Volts X Amps - at 120 volts, 50 amps produces 6,000 watts as opposed to 30 amps which produces 3,600 watts. Quite a difference. Ah, but there is more to the story.
Remember at the beginning when we talked about a 30-amp power cord having 3 prongs? Well, those three prongs correspond to a hot 120-volt wire, a ground wire, and a neutral wire.
But the 50-amp power cord has 4 prongs. Those four prongs correspond to a ground wire, a neutral wire, and 2 120-volt hot wires!
So, going back to our equation - Watts = Volts X Amps - we have 2 50-amp lines at 120 volts each. We have two lines capable of 6,000 watts each, not just one. Our total is now 12,000 watts of potential power for 50-amp service as opposed to only 3,600 watts for 30-amp service. Now you can see why 50-amp service gives us so much more capability than 30-amp service.
Another note on 50-amp service. Almost all RVs are wired such that the two 50-amp, 120-volt lines are used separately. In other words, some of the appliances are wired to one hot leg of the 50-amp service and the remaining appliances are wired to the other hot leg of the 50-amp service.
And now we also know why there are two 50-amp breaker switches shown on our pedestals - one for each hot line. But even though there are two switches marked "50", they do not operate independently. The whole circuit will trip if one line is overloaded.
Finally, this is another good reason to have a 50-amp surge protector with voltage protection on your 50-amp rig. Those devices test both lines of the 50-amp service and protect all your appliances no matter which leg they may be on. If you do not have one of these devices, one bad leg could be the reason some appliances work and others don't. However, one bad leg will probably lead to much worse problems than that.
The neutral in a 50-amp circuit is there to help balance the total 240 volts between the two hot lines so they each carry only 120 volts and no more.

so wether or not you use the two 120v legs to created 240v in your rig the pedestal is essentially a 240v panel as pointed out above every other breaker in your panel uses a different 120v leg therefore with only one 120 volt leg half of your breakers will not be powered

You're half right but check your breaker box when hooked up to a 30 amp pigtail splitter and you will find the whole box energized. The single 30 amp feed will split to both legs. I have used 30 amp hookups many times and everything has power.

[gewilli]

Back to the slide, what type do you have, HWH hydraulic? HWH has great customer tech support. Can you hear the pump run? Do the jacks work? The problem may be as simple as low on hydraulic fluid or a fuse or a little tougher like a shuttle valve. It isn't your power supply. You can and should run the engine when moving your slides on most rigs due to power drain.

Also your manual will have trouble shooting guide.

Good luck.

[Dr4Film]

To answer the OP's question and not get into a pissing contest over 50 amp versus 30 amp, the batteries will charge at the same rate whether you are using 30 amp or 50 amp shore power service. It is your converter that keeps your batteries charged. It depends on what that is set at for and charge rate.

There are so many other things that could be the reason your batteries are not charging. You have to look at each one separately to trouble-shoot the problem.

Also, there are many reasons why your slides will not work correctly and they may or may not be related to your batteries.

To correct some really BAD information stated in this thread earlier, when using 50 amps for a 50 amp RV, there are two 50 amp 120 VAC lines, Leg #1 and Leg #2 servicing the RV. Therefore there are 12000 watts of power available to use total. The RV does NOT use 240 VAC anywhere. It only uses 120 VAC to supply the main circuit breaker panel. The RV is then internally wired and split into two halves where one half of the RV runs on Leg #1 and the other half runs on Leg #2, each 120 VAC, NOT 240 VAC.

A 30 amp service is only 120 VAC with 3600 watts available to use at any given time. If your 50 amp coach is hooked to 30 amp shore power service using a properly wired 30-50 amp dog-bone, the HOT leg is wired to both Legs, #1 & #2, internally inside the 30-50 amp dog-bone. You will ALWAYS have both halves of the RV supplied with power. If you don't then you either have a bad dog-bone or your problem is inside the RV at the main circuit panel, transfer switch, inverter, or other places.

For those that don't completely understand RV electrical systems, I would HIGHLY recommend reading the web site listed below. If you still don't understand it, then it is best to have a professional electrician read it and hopefully they will understand it. Some do and some do not because they think they know it all. And I know for a fact the some of these electrical professionals HAVE wired 120 VAC receptacles wrong in owners houses and unfortunately caused thousands of dollars of electrical damage to RV electrical systems, because they thought they knew it all.

RV Electric

Dr4Film ----- Richard