Norcold N8LX Hi DC Fault Error With Power Converter on

[indie]

Hi,

I was searching around for any info that would help me troubleshoot a hi DC fault error on my brand new Norcold refrigerator and came across this forum. I hope perhaps one of the many knowledgeable members here might be able to help.

With the help of a handy friend, I recently upgraded my old fridge with a brand new norcold N8LX two-way model. The removal of the old fridge and installation of the new one went very smoothly, using existing DC power cables already there, which measured between 12.8-13.1 volts. The first power up after installation everything ran great for two hours until I turned on the generator and 45 amp Power Converter/Battery Charger, and then the fridge immediately gave a Hi DC Fault error.

I turned off the fridge immediately and checked voltage at the DC lines to the fridge with the Generator/ Converter on (fridge off) and the voltage was 14.l, well below the 16.0 Max indicated in the Norcold specs.

I also checked the AC voltage at the outlet where the fridge was plugged (it's a 2 way) and the AC voltage was 123, also within max specs.

Next I tried running the fridge on AC Power only, as a test, but that was not possible because the Hi DC error popped up again, as DC lines are always connected on this fridge.

After a bit of Googling around I read on a Norcold site that it is possible-- given the troubleshooting that I performed to verify that the fridge was working perfectly before the power inverter was turned on-- that the problem has to do with the DC lines that I'm using being "unfiltered" from the converter, causing "AC ripple".

If that's the case I'm not quite sure how to solve the problem because I basically used the same lines that were being used in the older fridge. It's true that the older fridge did not have an electronic control board so perhaps that setup won't work with this newer model.

It's not really easy or convenient to trace those DC lines back to the source either or I would do that, so my thought would be-- unless someone is familiar with this problem and has another suggestion-- perhaps the best solution is to just run clean DC lines directly from the battery to the refrigerator using a 6 amp fuse (to spec) in between.

I was trying to avoid running new lines, the less wires the better, usually, but at the same time I absolutely must be able to run the generator and converter to charge the trailer battery without the fridge throwing a fault.

Right now I have the generator and converter off and the fridge is about 5 hours into its first Power Up Cycle after the new installation and everything is working great so I thought I would reach out for some input before going to that effort of running clean DC lines directly from the battery tomorrow.

Any advice anyone can offer on this situation would be so greatly appreciated.

Thanks in advance!

Indie

[Old-Biscuit]

Thanks for the update!

It is MUCH appreciated when folks post resolution.

COLD is good :B

[indie]

Quick confirmation: Ran the dc power direct from the battery today as per Norcold specs and no more fault error. Everything is working great.

Many thanks to everyone who replied, especially Old-Biscuit. Hope this thread will help others searching with with same problem as well.

Great forum!

Indie

[Chris_Bryant]

Just move the line that powers the refrigerator to the right hand fuse on the fuse panel, which is filtered. No need to run a new line.
All new refrigerators have the same problem, they actually rectify the ac ripple giving high internal voltage.

[indie]

Hi Old-Biscuit,

Did I say INverter? Definitely meant CONverter! (lol). Long day.

Thanks so much once again for the very detailed reply. The confirmation is indeed helpful, as is the feedback on the Converter specs.

So tomorrow a direct DC line from the battery to the fridge is the plan. I'll report back to confirm success so the thread is updated for anyone else that might have this issue.

And it seems like plenty of people do.

Did a bit more Googling around and apparently AC Ripple seems to be particularly problematic with Norcolds, even in brand new RVs.

Bypassing the converter with a direct wire to the battery seems to work, as reported on several other forms I just found while still searching.

In fact, looking closely at the installation manual from Norcold, a direct wire to the battery using 18 AWG wire and a 6 amp fuse is precisely what they instruct to do. Not sure why so may RVs are wired the other way.

That said, I may have the Converter upgraded eventually, down the road. I have completely remodeled my travel trailer-which was in amazingly excellent condition for starters-- but now I've completely remodeled it with all new 2018 bells and whistles, including a brand new fridge, so I suppose that's a pretty important item to update as well.

Meanwhile I'll give the battery rewire a go in the morning.

Thanks again!

Indie

[Old-Biscuit]

indie wrote:
Hi Old-Biscuit,

Thanks for such a good detailed reply. I will test AC ripple as suggested and see if it's 6v or less.

As for the additional troubleshooting with a direct battery connection, I'm running with DC power now from the battery with *no inverter* and everything is fine, so I don't think it's the board, it looks like AC Ripple.

Indie

CONverter not INverter
Converter...120V AC IN/12V DC UT
Inverter....12V DC IN/120V AC OUT

Direct 12V DC from battery to fridge will work......only need to run POS wire and use a 6A in-line fuse for protection (install close to battery)

Fridge working properly using that direct wire...control board OK and the issue IS the DC from that Old MagneTek Converter (Parallax LLC)

Appears that only TOP 3 fuses are 'filtered'
Bottom 6 fuses are 'unfiltered'
:S

[indie]

Hi Old-Biscuit,

Thanks for such a good detailed reply. I will test AC ripple as suggested and see if it's 6v or less.

As for the additional troubleshooting with a direct battery connection, I'm running with DC power now from the battery with *no inverter* and everything is fine, so I don't think it's the board, it looks like AC Ripple.

Indie

[indie]

Hi, thanks for the quick replies!

It's an older 98 Salem by Cobra trailer that is in really excellent condition, considering the age. That said, I do know how it can be to try and integrate 20 yr old technology.

The Converter is a MagneTek Series 6300 A Model 6345 45 Amp Power Converter w Battery Charger.

I'm wondering if I did run a direct DC line from the battery directly to the fridge, if I would still have this problem when the inverter was on, verses using those cables that were already there for the old fridge.
I would be bypassing the converter altogether.

Would this solve the AC ripple?

I'd rather do that then of course upgrade the converter. I don't think that's a good option for me.

Thanks so much again for any inside and help!

Indie

[Old-Biscuit]

DC HI Voltage error code.....DC voltage above 15.4V DC
Normal operating DC range is 10.5V DC to 15.4V DC

DC to your fridge connects to terminals ON the circuit board
DC POS connects to the '12VDC' terminal
DC NEG connects to the 'GND1' terminal


To measure AC Ripple------
Use voltmeter set to AC and then measure the DC Pos/Neg at fridge DC terminal
More then 6V AC and fridge circuit board can cause issues with false errors even turn fridge off

When an AC/DC converter is used to supply DC power, the refrigerator circuit must be connected to the appliance output terminals of the converter (filtered side).
You should go thru the DC Dist Panel where the various fuses are located and ID which one is for the fridge.

If the refrigerator circuit is connected to the unfiltered side, the AC ripple
generated by the converter may cause a dc HI fault code to display.

To troubleshoot a dc HI fault, disconnect DC wires at fridge and connect a charged 12 volt automotive battery to the power board.
If the dc HI code clears, the fault was caused by unfiltered DC power.
If the dc HI code does not clear, replace the power board

[ScottG]

If you have a very old converter then this is indeed possible. If so then it's time to upgrade it.
The old fridge wouldn't care about ripple.

[pianotuna]

Hi,

Welcome to the forums!

What make and model of converter is in the RV?