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Topic: electrical puzzel ?? (Read 3 times) previous topic - next topic
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electrical puzzel ??
Yahoo Message Number: 146790
Our new (to us) 1998 26.5 LD has an electrical problem.  I replaced the original analog TV (it worked) with a newer flat screen digital TV and it wouldn't come on (plugged into the 120 v receptacle in the cab over entertainment center).  This plug showed 94-95 volts;  the other four 120 outlets all have 120-122 volts.  Looked into the convertor and discovered some toasted insulation on the ac neutral wires attached to the buss.  Installed the upgrade kit that Best Convertors sells, repaired the insulation and cleaned up the buss, turned it on and still 94-95 volts at that receptacle!  Any and all thoughts will be appreciated. Gordon Thistle
Re: electrical puzzel ??
Reply #1 –
Yahoo Message Number: 146791
Gordon,

I don't know this for a fact, but more than likely you are not measuring what you think.  I think you have an inverter that is converting your house battery 12 volt supply to AC for powering your entertainment gear.  This is whether or not you are plugged into street power and or running your generator or boondocking w/o AC power.  It could be your inverter is faulty or in could be that your inverter AC output is not "sine wave" but "simulated sine wave" which the meter has trouble dealing with.  If you plug say a 60 watt incandescent light bulb (i.e. something like a droplight) in that outlet and compare the light to that produced when plugged into the other rig AC outlets, you'll have your answer.  The inverter generated AC should give you a equally bright light.

But, ignoring for the moment the voltage problem, your new TV may have a problem dealing with the simulated sine wave AC.

Alex Rutchka, SE #4 '05 MB
Re: electrical puzzel ??
Reply #2 –
Yahoo Message Number: 146793
It sounds very much like an open, corroded or burned connection to that outlet.  AC voltage will couple capacitively across that kind of connection, resulting in reduced voltage to the load and very little current.  If you found burned wire insulation elsewhere, then it is possible that something plugged into that outlet overloaded the power system.

I suggest that you have a good technician check the power system.

Dale
Re: Electrical puzzle
Reply #3 –
Yahoo Message Number: 146794
It's likely, as Alex pointed out, that that particular outlet is not fed from the same source (generator or campground power) as the other AC outlets. In many older LDs that came with a TV, the factory installed an inverter to power the TV when camping without electrical hookups... and that inverter only fed the duplex outlet nearest the TV. If this is the case, there'll be a rocker switch nearby to turn on the inverter, which is in a concealed location near the batteries. (In a midbath, for example, it's under the fridge.)
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: electrical puzzel ??
Reply #4 –
Yahoo Message Number: 146795
Your problem is that the new TV will not work on most inverters? ? ? ?  This is hard to explane since I do not recall what the 2 different types of inverters are. But the better inverts put out a TRUE sign wave. I had a similar problem in that when I took a reading on the plug of my inverter. The inverter is putting out 120 V but it is a different kind of sign wave that most testers can not read. It takes a special tester that can read the sign wave that the inverter puts out. And this tester is not cheap. So the tester will read 94+/- volts and not 120. I just went out and checked my inverter output and the tester showed 94 V. And my TV is pluged into the inverter and working. It has worked for over 2 1/2 years.
I came accross this some years ago. I had something that would not work on the inverter. When I did a test I had 94 volt. I contacted a friend that is into this kind of thing because of his training and back ground.

George Retired plumber.
Re: electrical puzzel ??
Reply #5 –
Yahoo Message Number: 146798
It also depends upon the tester being used. I'm pretty sure my Fluke 87 can read those waveforms correctly. Of course an oscilloscope will also read the correct voltage.
 It is a definite problem with less expensive inverters that emit more of a square wave than a sinusoidal wave.

Dick