Quote:
Originally Posted by Richard Kollmann
Pete like you I recognize incorrect advise posted on the web and the lack of after market technical support in this boat refrigeration industry. Danfoss especially has held proprietary technical internal circuits of their electronic modules secret. Most job shops that market refrigeration units with Danfoss Secop BD compressors offer trouble correction charts like the one you follow. Unfortunately these charts do not cover the numerous design configuration used in pleasure boats today. When troubleshooting each different design the basic test must be altered too include that manufacturers design and their options.
The major problem with electronically controlled brushless 12/24 volt compressors is dirty electrical power from boat's on board electrical power grid.
Pete, the point I tried to make is refrigeration installed in a boat is exposed to trenchant voltage spikes that control module can interrupt preventing compressor from running while voltmeter can not. For a technician to rely on a voltmeter or ohm resistance to justify opening or condemning compressor is a mistake. Because 30 to 40% of system fail to boot up and run is caused by non related boat’s electrical wiring grid I recommend in my customized trouble chart a test powering complete refrigerator from another fully charged battery independent of all boat wiring. As far as the variable speed BD compressors I add a check to see if compressor gets warm after power is on for 20 minutes If compressor does get warm with LED code or not I again would bypass all boat’s power grid as a test before tampering with refrigerant or connecting a servicing hose. Replacing module will not correct pulse phase interruption do to a bad boat ground or a defective circuit board on Adler Barbour CU 100 or CU200 units.
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Richard, LOW VOLTAGE is by far the most common reason a 12VDC refrigeration system, that has worked fine for years, suddenly will not run. Easily identified using a Multi-meter as I described in point one. Now you can again divert away from the facts as much as you like but in reality it is as simple as that, very rarely transient voltage spikes, dirty power or ingrown toenails, just plain old low voltage.
Here is an explanation as to what happens... and why the suggested steps
work.. (This expands on our step one in post 9)
These Electronic
Motor Drivers (EMD) operate within a set voltage range. This operating 'window' has an upper parameter usually 17VDC and an adjustable low voltage parameter best set at approx 11.5VDC. Now while the voltage presented stays within these values the EMD remains in 'On mode' and will run the compressor on and off upon demand from the thermostat. But should the voltage drift outside these parameters (usually low voltage) the EMD will go into 'Off mode' .
To reboot into 'On mode the EMD has to 'see' a voltage approx one volt higher than the low voltage cut-out value so say 12.5VDC.
The most common cause of low voltage and therefore tripping the EMD into Off mode, is a failing battery system, poor cable, connection or device in the power supply chain. If it is a failing battery supply it is common for the EMD to drop into Off mode then stay off as the defective or flat battery can't present sufficient voltage to trip the EMD into On mode. On occasions when a partly defective supply is able to trip the EMD back into On mode the compressor may start but quickly the voltage dies and the Off mode occurs. This is a sure sign of a poor power supply again. Check as described in my post #9 using a MULTI-METER!
Now you also condemned my step 4 where we suggest checking the
motor winding resistance with a multi-meter to eliminate the rare possibility of a faulty compressor motor. Please explain how else someone with little more than a multi-meter at hand can confirm or otherwise if the compressor itself is ok.
Regards transient voltages (These are high voltage spikes that can travel along your DC power wires and may damage the EMD and erode compressor motor winding
insulation.)
As I reported on this forum earlier this year, it is a good idea to fit a Transient Voltage Arrestor, (AKA Voltage Clamp, Zorb, Transient voltage suppressor)
Transient Voltage Arrestors are fitted standard to Ozerfridge systems and I would highly recommend everyone fitting one to not only protect their fridge but other electronic items as well, after all they cost very little!! One device usually protects all electronic items connected to the same circuit but do not locate near the battery or any flammables.
And Richard, as I suggested to you in a post earlier this year, if you wish to continue disputing posts from industry people like ourselves, you might like to do so via PM or
email.. your call, I'm easy and enjoy the entertainment!
Cheers, OzePete
www.ozefridge.com.au