Problem with Grunert Passagemaker AC450 Refrigerator

[Passage Maker]

Hello All,

Hope someone has experienced this problem and may have some helpful debug guidance.

Problem Description:
When I turn on my refrigerator AC breaker on my A-bus power panel the sea water pump does not turn on, my generator voltage drops to about 30 AC Volts. The breaker on the power panel then may trip, may not. Some times the system will come up, other times the compressor will barely operate, the sea water pump doesn't turn on, I get high current demands and the breaker trips.

Debugging done so far:

Assumption: sense the pump sometimes will turn on and the refrigerator will run without issues due to intermittent problem, I'm assuming the pump and the compressor unit are good.

1. Pulled the Grunert electrical box cover off and checked the run capacitor with a multi meter. The capacitor charged from 0 ohms to infinite ohms indicating it is a good capacitor. AMRad P/N 33291 15 uF 370VAC 50-60Hz Motor Run capacitor
2. Checked the Motor Start capacitor BMI 092A270B330DE8X 270-324 uF 330VAC. The DE8X capacitor has a resistor tie between the pin connections thus should increase the RC time constant for a tuned charge time. I don' know if it should be long or short. The multi-meter check showed that the capacitor charged by very slowly. It was in the low ohms for several seconds. This to me suggests possibly the capacitor may be bad. I could never get it to go to infinity (fully charged).
3. When I measure the start capacitor in-circuit I measure 0 ohms across the leads. I don't have a schematic of the Start Relay so I don't know if the start capacitor is normally made when de-energized.

Any Idea's are welcome.

I cannot even begin to express my gratitude towards you. Our fridge (Grunnert 450) failed just like yours. We brought out our HVAC guy and he could not find the issue. I clearly remember him testing the capacitor and relay, and then we discussed. We were in talks with Sea Frost to replace evrything, (still waiting on a quote) and my son found this post. I didn't even bother doing the tests you described. I found a brand new relay $13 and change and contacted BMI (Paul Shockly is no longer there). They got right back with me with news of stock on hand. I ordered the capacitor ($54 with shipping), installed the 2 components and we have a working fridge!!!! Thank you thank you thank you

 

[JamesG161]

I had mine redone completely with new Compressor. Works great.



Jim...

 

[DeniseO30]

For future reference when you're all trying to source parts for the start and run of a compressor, refrigeration or air conditioning, try and determine the make and model number of the compressor instead of going back to the manufacturer of the equipment, you should be able to go to an HVAC supplythey will cross reference relays and capacitors for that compressor

I had to raise my eyebrows a bit on reading this is apparently old school equipment (I don't know how old it actually is) I was of the impression most people have done away with engine drive and 120 -230 volt for refrigeration and in lieu of 12/24 volt Refrigeration,

 

[Passage Maker]

For future reference when you're all trying to source parts for the start and run of a compressor, refrigeration or air conditioning, try and determine the make and model number of the compressor instead of going back to the manufacturer of the equipment, you should be able to go to an HVAC supplythey will cross reference relays and capacitors for that compressor

I had to raise my eyebrows a bit on reading this is apparently old school equipment (I don't know how old it actually is) I was of the impression most people have done away with engine drive and 120 -230 volt for refrigeration and in lieu of 12/24 volt Refrigeration,

The part numbers I used were not provided by Grunnert, They were provided by the member who made the original post. I compared those numbers to the numbers on my components. This boat came from the factory with 110V refrigeration, when it dies natural death it will likely be replaced with a 12V system

 

[JamesG161]

I had to raise my eyebrows a bit on reading this is apparently old school equipment

It is not OLD school at all.

The last Grunert Compressor used, came with 404r.
You can still get one made by a competitor, that the Grunert or Dometic People recommended.

Also Grunert[Dometic] gave me the newest 404r info [Since Freon® 22 has been abandoned from Bad info]
1) Tecumseh Compressor part number
2) Expansion Valves which mine has 2 ie. Freezer and Frig that are dual controlled.
3) The Freon® return filter.

There are sailboats bigger than 40 feet or even Power boats that use bigger Frezzer systems.

I have all that info, for Future Reference, if you need the Capacitor/Relay, in fact I bought a spare, if you need it
Part numbers direct from Dometic.
The biggest issue we had was the Relay had a required orientation in the Power box.

Jim...

 

[DeniseO30]

It is not OLD school at all.

The last Grunert Compressor used, came with 404r.
You can still get one made by a competitor, that the Grunert or Dometic People recommended.

Also Grunert[Dometic] gave me the newest 404r info [Since Freon® 22 has been abandoned from Bad info]
1) Tecumseh Compressor part number
2) Expansion Valves which mine has 2 ie. Freezer and Frig that are dual controlled.
3) The Freon® return filter.

There are sailboats bigger than 40 feet or even Power boats that use bigger Frezzer systems.

I have all that info, for Future Reference, if you need the Capacitor/Relay, in fact I bought a spare, if you need it
Part numbers direct from Dometic.
The biggest issue we had was the Relay had a required orientation in the Power box.

Jim...

Ah, I should have said old school wiring it was not an inference that the equipment is old but apparently Grunert likes to use tried and true technology that's old IE old school which is okay

Me? I'm retired HVAC business owner 50 plus years and yes I realize on larger boats voltage is usually not
a problem,

12/24 volt systems are quite small

I've been on boats that have walk-in boxes and when my business was thriving we often had cranes lift HVAC units to roofs that are as big as boats !

404a, 134a, 410a, 407, 22, 12, 11, were/are fairly common refrigerants, we no longer call them freon but the name persists, there are actually maybe a hundred or more different refrigerants for diffearent applications

Refrigerant - Types, Properties, Designation, Examples

Fluids suitable for refrigeration purposes can be classified into primary and secondary refrigerants. Primary refrigerants are those fluids, which are used

learnmech.com

 

[JamesG161]

we no longer call them freon but the name persists

Guess what happened.

Freon®

is back.

After years of Ozone study, the original model failed to be proved correct.

There are satellites monitoring this since the early 80's. No Ozone depletion, in fact increases with Solar Activity.
Jim...