High Amps on Refridgerator

[Richwink]

Hi
Our Alder-Babour CU-100 fridge (I think) has recently started to use more and more amps especially when starting up. It has gotten high enough recently to trip the 15 amp breaker. Do these fridges slowly lose charge or something and compensate by using more power?

Richard

[colemj]

Loosing charge would cause less amperage to be used. Overcharged would cause higher amperage draw. Have you checked the condenser to make sure it is clean and not clogged with dust bunnies?

Mark

[daletournier]

Im having problems with mine also. l believe the filter/dryer is blocked, causing a fas circulation probkem. Not sure where to source a new one. Maybe check that out.

Cheers Dale.

[Richard Kollmann]

Originally Posted by Richwink

Hi
Our Alder-Babour CU-100 fridge (I think) has recently started to use more and more amps especially when starting up. It has gotten high enough recently to trip the 15 amp breaker. Do these fridges slowly lose charge or something and compensate by using more power?

Richard

If the amperage is high enough to trip 15 amp breaker and still not blow fuse on front of stainless box, on Adler Barbour CU100, problem is not with refrigerant side of system. Problem is in boat's wiring or inside stainless box's circuit board. Review TECH TIP #1 on my web site for more information on AB circuit board failures.

[SimonV]

Ours has gradually increased in amps especially on start up. The fridge tech stated it's old and tired from continuous use. It may be time for a new unit. We are seeing 18 to 20 amps at start up and averaging 8 amps continuous. It's an AB DB50.

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[colemj]

The startup amp draw should be too fast to see. To fast to measure, even. How long does it draw 18-20A before settling down to 8A? I'm not sure "old and tired" applies to these compressors and current draw. I think there is probably another factor like partially plugged tube, or dust-filled condenser, or failed or failing fan, or bad power connector, etc.

I would check those things before installing a new unit. Particularly the power.

Mark

[SimonV]

18 to 20 amps are seen for 2 or 3 seconds and gradually come down and settle at 8 amps.

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[Richwink]

Hi

Ours takes about 10 seconds to settle down. I know the wiring is a little undersized becuase when I measure the voltage on the fridge connections it is about 1.5 volts less than battery voltage. However, 9 months ago the fridge would start at 8 amps and slowly go down to about 5 now it starts at 15 and goes to 8 - same wiring.

I will check for dust bunnies tomorrow but we have had completely blocked fins before and still didn't have the power draw.

RW

[DeepFrz]

These things are very sensitive to voltage drop. Just because it worked great 9 months ago doesn't mean your wiring connections haven't deteriorated. Run the power from your main power bus through a fuse or breaker directly to the fridge. Don't run the power from your main dc panel. Make sure your wire is sized correctly. Check Richard Kollmann's web site for advise or better yet, buy his book.

[familycruisers]

Sounds like corroded wiring and/or connections.

[Richard Kollmann]

Originally Posted by Richwink

Hi

Ours takes about 10 seconds to settle down. I know the wiring is a little undersized becuase when I measure the voltage on the fridge connections it is about 1.5 volts less than battery voltage. However, 9 months ago the fridge would start at 8 amps and slowly go down to about 5 now it starts at 15 and goes to 8 - same wiring.

I will check for dust bunnies tomorrow but we have had completely blocked fins before and still didn't have the power draw.

RW

Before the Danfoss BD50 control module see even 13 amps it will stop current flow. You have a boat wiring or Adler Barbour add on circuit board problem. Check board front and back for heat discoloring also check inside fuse holder

[Richwink]

Hi

Cleaned the ducts but they were pretty clean.

Richard Kollman - Your website rocks!!

Disconnected the thermostat and put in a jump from the thermostat connections on the compressor (C and T)

The fridge current went from up to 15, normally 12 on startup to 8 and running from 8 to 3.5. Checked the thermostat and it was completely corroded from sitting in water. The cover it was in didn't have a drain hole so if it filled during defrost or from a spill on the counter the thermostat would sit in water until it evaporated.

Questions:

1) What is normal running current on a CU-100?
2) What are normal running temperatures on the fridge?
3) Where can I get a new thermostat, West Marine and Defender seem to drawing a blank?
4) What is a normal price for a thermostat?
5) Ours is a spillover fan and thermostat worth adding, we have had a few frozen items on the fridge side before?
6) Any tips when changing out a thermostat?

Richard

[Richard Kollmann]

As long as BD50 12 volt compressor is operated with a thermostat differential off cycle long enough for pressure to equalize 5 minutes or more and ambient temperature is below 90 degrees F (32C). I assume refrigerant charge volume is correct with pure 134a refrigerant. A typical compressor starting amperage load looks like this:
With standard 101N0210 control module
Thermostat closes and compressor is unloaded at the time with equal High and Low pressures. Fan starts and stop as Compressor starts, it accelerates to 1950 Rpm minimum module control speed in two seconds or less. Amperage reading will begin and end anywhere from 5 to 6 amps. During this start up a 125 milliseconds spike will reach 11.5 amps for less than 50 milliseconds duration.

If your BD50 compressor has a 101N230 hard start module the spike is 17 amps.

Danfoss did not include a fuse to protect BD35 and BD50 compressor modules relying on owner to furnish a quality circuit breaker with no voltage drop under a quick small load.

The size of amperage spike produced by a BD50 lasting 125 millisecond would be hard to see. On my test stand with a 10 amp meter I can tell there is a spike of less than one second. I also have never seen amperage draw exceed 15 amps except when module has failed. So if you are having high amperage above modules high amperage safety cutoff I would question boats wiring and especially the ground wire for refrigeration unit and replace circuit breaker.

[Richwink]

Hi
Richard - Thanks again for the quick reply.

When I removed the modules to see if there were any burns on the AB module (there were none) I did remove and reconnect all the wiring between the modules and the boat. All the wiring and connections were clean but maybe reseating them helped with the high amperage.

I am still running the 15 amp fuse on the AB module but have jumpered the thermostat on the Waeco module. When I replace the thermostat I will go direct to the Waeco module. Why do you recommend a change out of the breaker?

You said that the amperage should settle out at 5 amps, mine is only 3.5-4 amps. Is this okay?

Richard

[GordMay]

Originally Posted by Richwink

Questions:
1) What is normal running current on a CU-100?

“... When in the starting mode, the ColdMachine may momentarily draw nearly 10 amps, even though the continuous running current is between 3 and 5 amps. If the electronic control module does not “see” at least 11.0V DC during the start period, it will abort ...”

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