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caheath · 11-21-2014, 03:14 PM

Hoping for some troubleshooting tips/suggestions to resolves issues with my inverter.

The inverter is a Dimensions Unlimited DUI-12/600 (600 watt). This little thing (when it works) powers the TV and AV equipment in the front of the motorhome - a 2004 Dolphin LX 6342. I am having two issues with the inverter:

#1 - when I hook up to campground power, I almost always have to fiddle and reset the trip button on the GFI outlet that is built into the inverter, and which provides AC to the TV/etc circuit. I am thinking I should replace this GFI outlet... ? Any tips on doing this? The inverter case looks to be riveted together but I can't tell.

#2 - the inverter was working when I bought the motor home about three months ago. That is, when turned on it would power the TV/etc when running off the house batteries. It stopped working about a month ago and I haven't had the time, until now, to focus on getting it working again. I can fiddle with the GFI trip button all day long but cannot get any AC power out the outlet. Yes, the inverter is turned on AT THE UNIT and also the REMOTE switch. The Low Battery indicator is not lit. Ideas on steps to troubleshoot?

Question: Physically next to the inverter is a Parallax 7400 Series Converter/Battery charger. I am NOT having any issues with the batteries properly charging - all is fine. But I'm wondering if the DC voltage input to the Inverter is provided by this Parallax unit? And, if so, is there a fuse somewhere I need to check?

Thanks!

JJH3rd · 11-21-2014, 05:17 PM

my first question is why are you using the inverter at all when on shore power? As you stated in #2 the inverter draws power from the house batteries and provides "AC" power to the system.

The "Parallax 7400 Series Converter/Battery charger" is a second inverter (converter) so how is all this stuff fit together? Sounds like you have an AC/DC war going on in there. Why isn't the Dimensions Unlimited DUI-12/600 connectred directly to the house batteries?

Just wonder'n.

caheath · 11-22-2014, 07:48 AM

Quote:

Originally Posted by JJH3rd

my first question is why are you using the inverter at all when on shore power? As you stated in #2 the inverter draws power from the house batteries and provides "AC" power to the system.

The "Parallax 7400 Series Converter/Battery charger" is a second inverter (converter) so how is all this stuff fit together? Sounds like you have an AC/DC war going on in there. Why isn't the Dimensions Unlimited DUI-12/600 connectred directly to the house batteries?

Just wonder'n.

Not using the Inverter when on shore power. However, the AC (as opposed to DC) power for the front entertainment system runs through the inverter when hooked up to shore power, and is fed through the GFI outlet... which trips a lot. Hence my question about replacing the GFI outlet.

Yes, one of my questions for issue #2 is "how is all this stuff fit together?" As far as I can tell, this is the factory original configuration.

TexasTom · 11-22-2014, 08:14 AM

That is how mine is configured. Power for those outlets comes from the inverter. No bypass when plugged in to shore power. So that means the batteries are always powering that A C circuit, which is not optimal when running off batteries only.

nothermark · 11-22-2014, 08:33 AM

I don't know about optimal as it is the only way one would get AC power when running off battery, ;-)

It sounds like the setup always runs off the battery thus using the battery and inverter as an Uninterruptible Power Supply and general power cleanup system. Sort of an elegant way to do it. When on AC the Parallax is supplying DC to the battery and the DC circuits in the MH including the inverter. That is a typical low end installation used in most MH's.

The place I would start is to trace the wires back and see if they run to the converter or a fuse panel. If I had and real questions I'd disconnect power and drill the pop rivets to get into the Inverter so I could check on what was going on. YMMV.

The GFI is an iffy call. They are notoriously finicky so replacing it is probably the easiest way to troubleshoot it. If the new one keeps popping you have a ground somewhere you do not want one.

YC1 · 11-22-2014, 09:01 AM

You need to measure the DC voltage at the input to the inverter first. Loose wires could easily cause an issue.

M&EM · 11-22-2014, 09:57 AM

Quote:

Originally Posted by TexasTom

That is how mine is configured. Power for those outlets comes from the inverter. No bypass when plugged in to shore power. So that means the batteries are always powering that A C circuit, which is not optimal when running off batteries only.

The inverter the OP refers to DOES have a bypass in the form of an internal transfer relay! This transfer device requires 12 volts.

If shore power is available at the inverter, it passes thru to the outlets---ONLY if the inverter has a 12 volt supply connected to its dc inputs.

chboone · 11-22-2014, 10:39 AM

If your Battery Control Center (BCC) is similar to mine and the inverter was installed by National the inverter is fed through a circuit breaker on the BCC. The inverter breaker on my BCC is in the upper right corner on the board. There is a reset button on the side of the breaker.

caheath · 11-24-2014, 09:24 AM

The weather is getting a little more user-friendly and I hope to be spending time today in the BCC compartment with the inverter, etc. Will be checking breakers, fuses, etc.

I am wondering if the inverter's TRANSFER SWITCH is "stuck" in position to pass AC? Does anyone have thoughts as to what triggers the transfer switch to pass DC from the batteries when not connected to shore power?

M&EM · 11-24-2014, 09:52 AM

The transfer circuitry,(relay) in the inverter is associated with allowing shore power to pass straight thru to the ac outlet plug When:

shore power is present AND dc 12 volts is present at the inverters' input And inverter is set to OFF.
IF inverter switch is on, AND 12 volts is available, THEN the ac outlet of the inverter will provide BOTH shore power or inverter power to the outlet with shore power given priority.

This how the same inverter I have works. The aux wire(purple) of the inverter is for a remote switch to turn on the inverter using a switch that NRV locates near the entry door. This also needs 12 volts to function.

caheath · 11-24-2014, 10:49 AM

Quote:

Originally Posted by M&EM

The transfer circuitry,(relay) in the inverter is associated with allowing shore power to pass straight thru to the ac outlet plug When:

shore power is present AND dc 12 volts is present at the inverters' input And inverter is set to OFF.
IF inverter switch is on, AND 12 volts is available, THEN the ac outlet of the inverter will provide BOTH shore power or inverter power to the outlet with shore power given priority.

This how the same inverter I have works. The aux wire(purple) of the inverter is for a remote switch to turn on the inverter using a switch that NRV locates near the entry door. This also needs 12 volts to function.

My Dolphin DOES have the remote switch mounted at the entry way. It is my understanding that it this switch actually controls whether the Inverter is ON or OFF... and that proper operation requires the ON/OFF slide switch on the front of the inverter to be left in the ON position.

The remote switch illuminates when in the ON position, but I *assume* the lamp is getting its power from the battery side and so just because it is lit does not mean it is working properly. Am I on the right track?

caheath · 11-26-2014, 09:45 AM

Quote:

Originally Posted by chboone

If your Battery Control Center (BCC) is similar to mine and the inverter was installed by National the inverter is fed through a circuit breaker on the BCC. The inverter breaker on my BCC is in the upper right corner on the board. There is a reset button on the side of the breaker.

The 12Vdc Power Dist Diagram for my Dolphin also shows a CB with a reset (see attached), but I can't find it... would you please describe to me what it looks like, or upload a pic?

YC1 · 11-26-2014, 01:00 PM

http://www.wiringproducts.com/short-...unting-bracket

The breaker may look like this. Could be a metal housing.

chboone · 11-26-2014, 11:34 PM

Quote:

Originally Posted by caheath

The 12Vdc Power Dist Diagram for my Dolphin also shows a CB with a reset (see attached), but I can't find it... would you please describe to me what it looks like, or upload a pic?

The circuit breakers, there's three of them, upper right, upper left, and lower right corners are on the back side of the board. The only one on my board that is easy to see is the upper left.