342 Refrigerator Wiring

politby

First of all, great to see this forum has come alive!

I think I have a problem with a voltage drop at the DC panel in the galley. My Waeco fridges, which apparently are really sensitive to dips in voltage, go into an infinite on/off loop as soon as the batteries are not charging from shore or alternator power. 

I have two brand new deep cycle house batteries monitored by a battery health monitor which tells me the voltage measured directly at the batteries never drops below 11.8V even at 70% discharge. However the voltmeter on the DC panel shows a much lower voltage, below 11. I always put that down to an unreliable instrument but now that the fridges are acting up I am starting to think maybe that reading is correct. I am going to drop the DC panel and make some proper readings, but I need to find out how this is wired in case I have to pull new wires.

If I understand it correctly the DC panel is supplied by a wire from the main power panel in the recess on the aft bulkhead. How is that wire, and its corresponding ground wire, routed to the galley? 

I also assume the cockpit fridge is powered from the DC panel. Because both fridges exhibit the same problem the voltage drop would have to occur before both refrigerator feeds (unless both fridges are broken - unlikely?).

How difficult is it to work on the wiring to/from the DC panel? I have pulled wires/cables from the engine bay through the starboard side to the helm and that was not too bad but unfortunately that allowed me to see the quality of Rinker's electrical installation - shudder

raybo3

What year is your boat? I do not have a voltage problem with my 342 and did this just start to happen? If this is a fairly new problem then maybe its just a bad connection somewhere. Try troubleshooting it and see where the drop is coming from. Good luck and keep us posted..

politby

It's a 2002. When I bought it in August 2010 the PO had just replaced the galley fridge with a Waeco CR-120. For the remainder of that season we were always on shore power so I did not notice anything.
Before the 2011 season I replaced the old cockpit fridge with a Waeco CR-65. I first noticed the red LEDs flashing after that.

It's not until now it has become really annoying because we go to more places where no shore power is available.

I spent some time checking the voltages today. I could not measure directly at the fridges because I did not have enough time to pull them out. But I used the 12V cig outlet as a measuring point for the voltage at the DC panel.

There is no significant voltage drop between the battery terminals and the 12V outlet. This is regardless of actual power draw. So any voltage drop causing the fridges to repeatedly power cycle must be occurring across the wiring from the DC panel to the fridges.

I let the batteries charge fully and then turned off shore power. Voltage at battery terminals and cabin 12V outlet was 12.6V at this point.
With one fridge running drawing approx. 4.4A voltage held steady at 12.6 volts. None of the fridges was flashing its low voltage light. At which point I left the boat.

3 hours later I returned to find both fridges flashing the red LED. Voltage still 12.6 volts at both points.

So either the fridges' power wiring is flaky or BOTH fridges - one purchased in Sweden in 2010, one mail ordered from the UK in 2011 - have faulty power boards.

Thoughts?

raybo3

Ok a little confused at what your saying. Your first post said the meter was below 11. I would try running 1 fridge at a time. I am thinking that maybe the new fridge might be draining the batteries causing the lights to flash..

Black_Diamond

Odd both would do that. Sounds like a connection issue to me. Start with the grounds.

Michael T

I'm with BD, sounds like a ground. MT

politby

@Ray: Yes the meter at the DC panel reads below 11, but I think I can confirm it is broken since the 12V outlet is not showing any voltage drop at load (TV + WDTV). If there is a voltage drop causing the fridge issue, it is present on the fridge feed only.

And the batteries are not being drained. Voltage at battery is rock stable at 12.6V and 85% of capacity this morning after boat was left overnight off shore power with fridges "operating".

I agree it must be a connection issue. Will pull out one fridge and run it directly off the battery to test.

What is so strange is that they run fine for a while with no appreciable battery depletion and THEN start acting up.

Probably better to run completely new wiring to both fridges rather than waste time on troubleshooting.

raybo3

Ahh got it. I would check all the grounds and make sure they are clean and tight. Does not take much to have a bad connection. Good luck and keep us posted....

politby

Found the cause of the problem - the cockpit fridge. I switched it completely off and tried with just the galley fridge - problem gone.

When I installed the new cockpit fridge I just connected it to the old (Norcool?) fridge's wiring which apparently is inadequate for the Waeco.

It's likely to be a tough task to re-run new wires from the galley panel to the cockpit fridge so I may just run directly from the aft switch panel instead and add a separate switch at the wetbar.

hanzelvh

I had same experience with my galley fridge.

At the 12V outlet 12,6 V and at the fridge wiring just 11 V due to huge voltage drop (thin wires??).

Waeco stops at 10,5 so after short time it comes into loop of starting/stopping etc and worst part: no cold beer!

Solved it by inserting a DC-DC converter of Victron which makes 12,5 V of every thing from 9,5V and higher. Use this now since 2 years and no problems any more. 

Black_Diamond

No cold beer is scary! lol