Two electrical questions

**rimartin58** · 11-01-2008, 02:40 PM

I've just done some wiring additions to my TM and have two questions:

1) I was reading a back issue of MotorHome the other day and the article said that you should not run your converter without a battery installed because it's bad for the unit. The article also mentioned that battery disconnect switches (which have been discussed on this forum) create the same problem.

Can anyone explain why this would be so?

2) I installed an additional plug on the inside of the rear cabinet (under the back bed) so I could get 110v power closer to the back of the trailer. Originally I installed a 20A dual receptacle in place of the single receptacle that powers the AC. Imagine my surprise when it didn't fit (I know, I should have looked and I did look, but the subtleties of the plug escaped me!).

Here's the question -- why does TM install a 20A 220v plug on a 110v service for the AC? I can see how they might do that to insure the 20A circuit was only used for the AC, but I don't really know why that would be so important unless they were worried about people getting low amps to the AC and/or tripping the breaker.

Thanks.

RIM

11-02-2008, 08:32 AM

1) Chances are that the converter expects a specific type of load on the battery connection, and with the battery out of the circuit you'd then have electrical conditions the converter isn't designed to handle. Something analogous to this is true in a LOT of electrical/electronic circuits.

2) I've not seen this plug, so I can't help you there, but I'd hate to have anything else on the A/C circuit with the A/C running -- it pulls a LOT of juice.

**rimartin58** · 11-02-2008, 10:01 AM

I think you're right. I think I've got enough knowledge of electricity so that I know not to use my new plug unless the AC is out of service (I'm thinking about the plug for an electrical heater primarily, so I wouldn't be running them together), but I could see why most people would assume "there are two plugs here, I can use them both at the same time." Then again, that's what the breaker is designed to protect against.

But also, why not wire up a single outlet, 20V 110 plug? That way only one appliance could be in the circuit at a time?

But we're talking about engineers here. Being both a therapist and an engineer, I know that engineers think they're rational. The truth, they're just as crazy as everybody else.

RIM

11-02-2008, 02:35 PM

I once tried to run two 1500 watt electric heaters. But, no matter what outlets I used, the breaker kept popping. duh. All 110 outlets in the TM are on a single breaker. There is capacity to plug in 10 (5 duplex) different things, but there is only 20 amps for all of them combined.

So I ran an extension cord from a 20 amp plug on the power pedestal through the shells into the TM where I could then plug in a second heater.

**Caver** · 11-02-2008, 03:03 PM

Quote:

Originally Posted by rimartin58

1) I was reading a back issue of MotorHome the other day and the article said that you should not run your converter without a battery installed because it's bad for the unit. The article also mentioned that battery disconnect switches (which have been discussed on this forum) create the same problem.

Can anyone explain why this would be so?

RIM, If you have the original converter in your 2001 TM it did not include much filtering or any regulation. TM switched converters during the 2004 model year. It would not be a good idea to use the original converter without a battery. The newer TMs and replacement converters should operate fine without a battery. Best to check the specific converter with the manufacturer's recommendations.

Good luck. Ray

11-02-2008, 03:43 PM

Most electric space heaters are 15A or a little less. You need another breaker and a separate GFI outlet to do it correctly. For how I did it see my post under this subject;
http://www.trailmanorowners.com/foru...ead.php?t=4933

**rimartin58** · 11-02-2008, 05:15 PM

Okay. I have the following 110v breakers in my converter:

A 30A for the main power
A half width 20A for the AC
A half width 20A for the converter
A 15A for the GFI

Am I right to assume that the 20A only powers the AC and all the other receptacles run off the GFI? If so, I should be fine running a heater off that circuit when the AC's not connected.

Do they make half-width GFI breakers? That's the only way I see that I could get another circuit in the box the way Alrhall did it.

Thanks

RIM

**rimartin58** · 11-02-2008, 05:18 PM

Quote:

Originally Posted by Caver

RIM, If you have the original converter in your 2001 TM it did not include much filtering or any regulation. TM switched converters during the 2004 model year. It would not be a good idea to use the original converter without a battery. The newer TMs and replacement converters should operate fine without a battery. Best to check the specific converter with the manufacturer's recommendations. Good luck. Ray

Makes me wonder if spending the money for a new converter would be a wise investment. I already have trouble with the radio due to the unfiltered 12V circuit. Anybody know how many 110v breaker slots you get with a newer unit?

Thanks

RIM

**Bill** · 11-03-2008, 11:57 AM

The half-width 20 amp breaker for the converter most likely also provides AC power to the refrigerator. At least that was how both my old 2002 TM, and my new 2006 TM, were wired.

Bill