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dabrooks · 11-09-2013, 10:02 AM

We were in Cherokee this past week dry camping. We found a nice level spot and put the jacks down and the slides out. We went in the casino for a while and came back out for the evening.

I started the generator ( Onan 7000) and put the tvs on and the propane furnaces to take the initial chill off before I turned on the heat pump. The wife used the microwave and the Kuerig coffee maker. I turned off the two furnaces and waited about 5 minutes and then turned on the front roof mounted heat pump. both tvs went off immediatley. I turned them back on and they stayed on. I turned the heat pump off and switched on the inverter for the TVs. After about 5 minutes I turned the heat pump back on without incident (the tvs stayed on).

After I got home I went out this morning and went through the same procedure and it did the same thing. I shut everything down and plugged in to my 50amp service and when I turn on the heat pump the TVs stay on.

I have 2013 Tiffin 35qba and I believe the roof air/heat pump is 15500 btu unit. As I stated earlier the generator is an Onan 7000.

Any ideas ?

Cooperhawk · 11-09-2013, 10:17 AM

A power outage will shut your TVs off and it could be that when you turned on the heat pump it surged the power just enough to make the TVs think there was an interruption in power.

dabrooks · 11-09-2013, 10:45 AM

I am sure that is what's going on but it does not happen on ground power Only when the generator is used. It may or may not be an issue worth worrying about but I want to see what others think. It is really no problem to use the inverter and then the tvs stay on.

mel s · 11-09-2013, 11:24 AM

Quote:

Originally Posted by dabrooks

I started the generator ( Onan 7000) and put the tvs on and the propane furnaces to take the initial chill off before I turned on the heat pump. The wife used the microwave and the Kuerig coffee maker. I turned off the two furnaces and waited about 5 minutes and then turned on the front roof mounted heat pump. both tvs went off immediatley. I turned them back on and they stayed on.

Any ideas ?

Some TVs will immediately go OFF if/when they momentarily see low voltage, (or momentarily loose 12OVAC).

IF/when your coach is operating on generator power and you turn your heat pump ON, the initial start-up electrical draw may momentarily slow the generator, (which momentarily stops, or drops, the AC voltage), causing the TVs to turn OFF, (and requiring you to turn them back ON).

My LED TV often turns OFF when I turn on any large electrical draw, (roof air, microwave, etc) while I am operating on generator power.....
However, the TV never turns OFF when other 120VAC appliances are turned ON when I have shore power, (50A, 30A or 20A)!

IMO, although it is inconvenient and annoying.... the fact that the TVs turn OFF when a heat pump is turned ON is NOT necessarily an indication that something is wrong.

My 2 cents, (which may be wrong)!

Mel
'96 Sahara, 6.3 kw Onan, 19" LED TV

TXiceman · 11-09-2013, 11:55 AM

More than likely, the heat pump cause a voltage dip on the generator which is low enough that the TV will drop off.

Ken

dabrooks · 11-09-2013, 01:46 PM

It seems from the opinions for I don't have a problem. I didn't leave everything on long enough to see if it is only the initial star-up or every time the heat pump comes on. It really isn't a problem I can just let the TVs run off the inverter when using the generator. I also forgot to mention that I did retighten all the electrical connections. I did not find anything lose.

Ray,IN · 11-09-2013, 02:27 PM

If the genset was cold, it might have stumbled when the increased load was applied, causing said voltage dip.

94-Newmar · 11-09-2013, 04:10 PM

Inverter generators will "sag" substantially more than their non-inverter counterparts due to the mechanical delay as the engine must ramp up to speed to meet the demand of the load. As mentioned, some new electronic equipment is rather sensitive to voltage changes (drops) and will simply shut down on very minute changes. That being said, simply turning on the AC/Heat Pump unit should not have caused that much of a drop as only the fan is turning on initially before the compressor starts a minute or so later. Since you're still under warranty, I'd have an onan/cummins dealer do a load check on this unit. A good load bank and tech will be able to load the unit and test it properly. You may have a controller going bad or out of spec range - better to catch it now under warranty as the controllers are not cheap.

wa8yxm · 11-11-2013, 08:54 AM

Not only the cold generator option, but I find my Genny sags when the compressors on the A/C kick in,, One thing that may (Depending on the A/C/heat pump) SLIGHTLY improve things is to run the fan in HIGH mode (not auto) as the fan in HIGH may start before the compressor (Thus taking it's starting current out of the equasion)

Another thing that will make the voltage drop greater is lack of exercise.. Generators need at least 1/2 hour under 1/2 load every month.,

dabrooks · 11-11-2013, 09:20 AM

I talked to the local Onan dealer today and he told me to run the genset at least 10 min and then see if the problem happened again. He said if it did to bring it by and he would test it on his load bank and also check the draw of the heat pump. I am going to test it today and report back. I do run the genny under load the 1st and 15th of each month. I do it when I take the motorhome out for it's 45 min ride.

dabrooks · 11-11-2013, 02:18 PM

Well I got the genset good and warm and also had the fan running on high when I turned on the heat pump. It did knock the TVs off again. I let it run through a cycle and when it came back on it knocked the TVs off again. I am going to run it up to Onan one day and get them to check it out.

mel s · 11-12-2013, 07:36 AM

Quote:

Originally Posted by dabrooks

Well I got the genset good and warm and also had the fan running on high when I turned on the heat pump. It did knock the TVs off again. I let it run through a cycle and when it came back on it knocked the TVs off again. I am going to run it up to Onan one day and get them to check it out.

dabrooks
I don't think you have an Onan problem!
IMO you simply have TVs which are sensitive to any slight voltage drop.

I solved my similar problem by adding/installing an inexpensive 300 watt MSW inverter which I use to power my LED TV, (and a DirecTV receiver), if/when the genset is running.

Mel
'96 Safari

dabrooks · 11-12-2013, 08:08 AM

Mel, I think you may be right. I do have an inverter and the TVs stay on when powered thru the inverter. Since the Onan service manager offered to do the tests and I do take the motorhome for rides on the 1st and 15th of each month I will let him check it and report back. Thanks for your input.