kollmann-marine.com

[JTucker]

Hello Spam hope all is well with you.
I moved back aboard and my 12V system ran for a week before failing to start. I'm fairly sure it is a BD 2.5 or BD 3 with the newer style module.
I have done the following tests and the compressor still won't start:
1. Took pos. and neg. leads directly from the battery.
2. Jumped out the thermostat.
3. Removed the pos. lead to the fan.
4. Tapped the compressor housing with a rubber mallet when it was trying to start.
5. Had 2 modules checked by Miller Marine and they report both work.
6. Tested resistance between terminals on the compressor with these results. 1-2 3.0 Ohms, 4-3 .5 Ohms, 2-3 2.8 Ohms. They appeart to be close to what you indicate other than the 1-2 which you indicate should be .2 Ohms.
7. I get a voltage drop of about .5V when the unit tries to start. This appears true when either it is getting aprox 13V or over 14V with the engine alternator running. The unit appears to be drawing about 5 amps at startup but I don't have a super sensitive amp meter.

The fan doesn't start, but I seem to remember it is on a delay. It does run when powered directly.
What do you think?
John
P.S. The engine drive system is working well, I am just getting tired of listening to the engine for 30-60 minutes per day.

[kollmann]

I am not sure who Spam is but OK. Without knowing the component design configuration or who built your system I am not sure I can help. Based on your comments there seems to be a boat wiring problem. Are you sure you followed my instructions in bypassing all refrigeration wiring in the boat by running large jumper wires direct from a fully charged battery direct to Danfoss electronic module?

Tests you should have done to eliminate no start problem cause on older BD2.5 or BD3 compressors:
1. Disconnected wires from module terminals C and D.
2. Placed a jumper across thermostat module terminals T and C.
3. Do not try to use voltmeter to look for voltage drop spikes unless you have superman’s eyes. Bypass all boat wiring for refrigerator.

If the above tests do no get compressor to run by itself and Miller confirmed Module was good the last thing to do is polish the electrical pins on compressor.

The only Danfoss BD compressors that I have ever confirmed as failures were either removed from water cooled condensing units or from systems with incorrectly designed holding plate coils.

[JTucker]

I typed in your first name, but when I submitted the post it appeared as Spam?

The system is an Adler Barbour 12 V R12 compressor, with an engine drive Sanko (?) compressor going to separate coils in a holding plate, built by you in about '97.

I have run jumpers from the battery to module using 10 gauge wire 10' in length. Should I try heavier gauge wire, it's a fairly short run?

I've jumped out the thermostat.

I'll try to polish the pins on the compressor, but have already cleaned them with contact cleaner.

[kollmann]

John I remember your system.
Your jumper wire size was OK. But recheck thermostat and both fan wires should be removed during test.

If problem is not electrical bring condensing unit to me. Be sure to cap lines when you remove unit.