Author Topic: BD Compressor Draws Current but Does Not Compress  (Read 7180 times)

mayball

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BD Compressor Draws Current but Does Not Compress
« on: February 23, 2014, 10:46:49 am »
Good Morning,

I am helping a friend with his Adler-Barbour BD-35 boat refrigerator. He had recently tried to patch a hole in his thin plate evaporator with epoxy and I was going to help him start it up. I found the unit turned off, with 85 psig on the suction tap (no discharge tap available). When the breaker was turned on, the fan runs for one minute drawing 0.6 amps. Concurrently, the compressor draws 4 amps at 12.8 volts, but does not run (the suction pressure does not diminish). Then, at the end of the one minute interval, the fans stops briefly. Then the compressor draws an instantaneous 15-20 amps, the fan starts up, and the compressor draws 4 amps again for a minute. This cycle continues while the compressor gets warmer, but the suction pressure never comes down. Thinking the rotor might be stuck, I gave the compressor a series of sharp blows with the heel of my hand, but no change. There is no LED installed.

Any ideas?

Don May
Don

Richard

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #1 on: February 23, 2014, 12:31:11 pm »
As far as I know AB has never use the BD35 compressor. A small cap tube system’s static pressure will not read 85 psi unless ambient temperature is above 90 degrees F. Instant rise of amperage above 10 amps is prevented by module and circuit breaker is to be 15 amp.. Compressor will not draw 4 amps unless it is running. A locked rotor would mean compressor did not reach module’s minimum speed quick enough stopping compressor. Suction pressure not reducing below 80 psi and drawing 4 amps indicates gauge error or incorrectly installed.

If this is the older BD3 fixed speed model 4 amps with a warm evaporator is not enough should be 5 amps an a 70 to 80 degree day.

If you remove blue hose from compressor will gauge pressure drop to zero? If not hose is type that meets EPA new standard and my not open compressor inlet valve.

If evaporator was patched how was patch tested to determine flow past it was still good?
Was air and moisture dehydrated before adding refrigerant?



mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #2 on: February 23, 2014, 01:10:12 pm »
The original, possibly BD3, compressor, had been replaced with a BD35. The ambient temperature could well have been above 90 degrees F. We are in Puerto Vallarta, Mexico. I will however check that pressure. The owner said he patched the evaporator without doing anything with the refrigerant charge. So maybe he did not have a leak where he patched it since one would think it would blow through the epoxy before it set.
Don

Richard

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #3 on: February 24, 2014, 03:55:40 pm »

The information you first reported is normal operation for both a BD3 and BD35, When power is turned Adler Barbour unit will start fan then a few seconds later when compressor starts fan will stop till compressor reaches 1900 rpm. The difference between a BD 3 and BD 35 is in the preset compressor control speed. The BD3 was fixed speed of 2500 rpm and amperage will be 5 to 5.5 amps when properly charged with refrigerant. Because the BD35 is a variable speed compressor and running amperage will vary from 3 to 6 amps depending on what size speed resistor is installed in thermostats wiring.

With the high suction pressures you reported and low amperage of compressor  running  may not have enough refrigerant to generate liquid in high pressure line. I would then assume your gauge set is at fault with 80 psi of pressure indicated.

My experience with these aluminum roll bond evaporators is once they leak they can not be patched. Internal or external corrosion will cause in the beginning micro small holes allowing refrigerant to leak out. In the beginning with just one very small hole it might take 6 weeks the first time and before long refrigerant needs to be added. It will not take long before more small holes will open up and leak rate will increase. Leak rate is much slower if evaporator is kept cold, leak rate will double if system is turned off,

mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #4 on: February 27, 2014, 02:12:33 pm »
I checked the operation and accuracy of my gages and they are accurate. I zeroed the digital gage and the valve depressor in the hose connection did depress the valve core. The voltage this time was 12.47 and the amperage was 4.25 on the unit and 0.70 on the fan. The pressure on the suction again was 85 psig, and did not diminish, nor did the compressor feel like it was running, although it did heat up over time. The discharge line running to the condenser did not seem to heat up, and there was no cooling at the plate. There is no resistor in the thermostat wiring.

If I were to install an LED, do you think it might flash a count? Could the rotor be stuck and still draw the 4 amps, but shut down because it did not reach minimum speed, or any speed at all?

Don May
Don

Richard

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #5 on: February 27, 2014, 04:12:28 pm »
Are you telling Me if you remove center yellow hose from gauge set and open Blue gauge valve refrigerant will come out center port?

If you see 0.70 amps yes compressor will not be allowed to run. That circuit is limited to .50 amps. The BD3 fan circuit was a one amp circuit while the BD35 circuit is limited to 1/2 amp. Remove Black Fan wire from Module terminal F. Now if compressor runs replace fan.

If LED is installed it will tell you the area where problem is located.

mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #6 on: February 27, 2014, 05:36:52 pm »
Yes, gas will, and did, come out the center port, so my blue hose was communicating with unit. I think you nailed it on the fan amperage. I saw in the specs that the diagnostic would give 2 flashes if the fan circuit was over 1 amp, but I did not know that it would not run at fan current over 0.5 amps. I think that is cutting it close since some common 4 inch fans draw 4.5 amps. It looks like I will need a relay on this unit.

Thanks Richard
Don

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #7 on: February 27, 2014, 10:23:09 pm »
Disconnect the F terminal Black wire and see if compressor will run...

mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #8 on: March 04, 2014, 03:59:33 pm »
Hi,
I finally got back on the boat and disconnected the F terminal black wire. The conditions remained the same. except the fan was not running therefore the power amperage was 3.5 amps. The compressor still does not run (suction pressure does not diminish) although it does draw the 3.5 amps at the power terminals of the module.  BTW, I had a typo in my last post: where I said 4.5 amps for a common fan, it should have been 0.45 amps.

I am going to start another thread on another boat in the same marina with a similar but different problem.
Don May
Don

Richard

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #9 on: March 05, 2014, 07:51:17 pm »
Three plus amps tells you compressor is running. Does compressor get warm if left on for 15 minutes?

I do not know what to tell you with the strange amperages and pressures you are getting. Try the tests I gave you on the Frigoboat unit and let static high pressure down to 60 psi.

mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #10 on: March 06, 2014, 06:04:53 am »
Richard,

Yes, the compressor does heat up after 15 minutes time at the 3.5 amp draw, but the line entering the condenser is not hot. I will try the tests you suggested for the Frigoboat and report back.

Thanks,
Don May
Don

Richard

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #11 on: March 06, 2014, 08:55:13 am »
Compressor gets warm, very good. With system turned off static refrigerant pressure should be in that warm climate 60 psi or higher. It is sometimes difficult to hear compressor or feel vibration when compressor is running by not having enough refrigerant to build a high side pressure.

The older fixed speed BD compressors had two field coils and rotation was achieved by reversing polarity 2500 times a minute to cause armature to rotate. This variable speed BD35 has three field coils so it runs on three phase pulses produced by the electronic module. I did experience one BD50 that performed like this because of an interrupted signal to a field coil. Final fix was a poor ground connection this is why I always recommend using correct polarity jumper wires direct from a fully charged battery direct to module eliminating all boat wiring.

mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #12 on: March 09, 2014, 03:12:50 pm »
This unit seems to have a different problem than the Frigoboat in the concurrent thread. When I closed the breaker with only the power wires connected and the jumper across the T and C terminals, the compressor also will not run. However, unlike the Frigoboat, the unit draws 3.4 amps, even with the thermostat terminals open. Also the heat fins on the module warm up and the compressor warms up over time. The resistance in all three windings was 2.6 ohms.
Don

Richard

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #13 on: March 10, 2014, 07:27:36 pm »

If you followed the instructions about eliminating all of boat's electrical wiring by powering module direct from a fully charged battery with nothing else attached but bypass at module thermostat terminals and still compressor is not turning it is time to try another module. Two weeks ago with the same indications trouble found was a bad battery ground that somehow stopped rotor inside compressor with pulses of less than three phase.

mayball

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Re: BD Compressor Draws Current but Does Not Compress
« Reply #14 on: April 12, 2014, 07:14:12 am »
I finally found another electronic module and installed it on the compressor. The unit now seems to be running although it needs more refrigerant. I still cannot understand how the old module would allow the unit to draw 4 amperes, but would not compress. Perhaps there was an unbalance in the three phase voltage provided to the compressor by the electronic module.
Don