Isotherm 5801 Cycling?? Anyone have an Isotherm?

[ssullivan]

My boat has an Isotherm 5801. That's the dual Danfoss compressor unit. The unit cools down a freezer holding plate in the freezer and there is a spill over refrigerator.

The PO ditched the ASU module because they kept blowing up on him. [Nice, guy, but he seemed to have that problem with a lot of electrical things on the boat. ]

Instead of the electronic control module, he has the old standard temperature switch, which was incorrectly measuring the freezer temp. I moved it to the refrigerator compartment to bring the unit down to proper temps.

The refrigerator keeps stuff at the appropriate temp in both the freezer and the refrigerator.

Works fine, usually.


EXCEPT... on occasion, the unit will run for about 1 minute, then switch off for 2-3 seconds, then run for one minute, then switch off for 2-3 seconds, over and over again.

I'm trying to figure out why this is happening. The refer and water circulation pump (water cooled) both shut off during that 2-3 seconds. It seems highly inefficent for that to be happening and probably a bit of a wear/tear issue as well.

So far, my theory is that the refer is trying to go into some automatic mode it no longer has...

Any ideas? Anyone with an Isotherm ever experience this?

I tried going to the Isotherm site for support, but it's not loading well...

[irwinsailor]

I can not help , other than to say that I bought a Isotherm last year and I spent a lot of time on the phone with them. I will say that I was happy with the support. I think that you will need to talk to Ron.

[ssullivan]

Thanks, Gunner. Is Ron in the USA, or Italy?

Also, adding to the thread, I was just down in the engine room and noticed that this is happening right now when only one of the two Danfosses is running, and the compressor *does not* stop. Only the saltwater pump is cycling. That's a bit of a relief, but still... would be good to know what's going on.

[irwinsailor]

Ron is in Florida, I think Fort Lauderdale. I have his phone number on the boat so I can not give it to you.

[irwinsailor]

I would check the water intake and make sure that it is not plugged. Also check the discharge

[GordMay]

Indel Webasto Marine USA
3400 Gateway Drive, Unit # 107,
Pompano Beach (just N. of Ft Lauderdale), FL - 33069
Phone: (954) 98-48448
Fax: (954) 979-2533
E-mail: info@indelwebastomarineusa.com
Web: www.indelwebastomarineusa.com

[windtraveler]

Ssullivan, did you ever figure out what the problem was with your unit? Mine just started having a similar issue... here's what mine does...

The compressor turns on, immediately starting the seawater pump, then the compressor shuts off after 2 seconds while the seawater pump remains on for about 70 seconds total before turning off. Then all is quiet for only 2-3 seconds before this cycle repeats. So, again... Compressor on for a split second before pump on, compressor off (after 2 seconds), pump stays on (70 seconds), pump off, 2-3 seconds quiet, repeat.

Other info: My voltage is currently at 12.38v. I cleaned out the seawater in-line filter. Discharge water is coming out over the side. Unit is a "Isotherm Compact Magnum". Danfoss BD50F compressor.

Please help!... We're in Nassau, Bahamas and the Exumas are calling... after this front passes in a few days that is.

Scott

[Richard Kollmann]

windtraveler, When compressor stops after 2 seconds it is not do to poor or no water cooling as condenser would not be warm enough to cause control module to see high amperage. Your BD50 troubleshooting LED would also be signaling three flashes if water cooling was the problem. You probably have a boat wiring problem if LED flashes one time every four seconds.

After 1995 only Danfoss BD 35 and BD50 energy efficient compressors were produced. One feature on all these new BD compressors is their ability to electronically advise an operator of the location of a problem. A troubleshooting micro processor similar to an automobile’s computer warning light can be installed that will flash a code indicating location of problem. On automobiles an expensive test meter is required to read troubleshooting information, but on BD compressors a simple LED connected to the Danfoss control unit flashes a code. By counting the number of troubleshooting LED code flashes, repeated every four seconds, the item causing the problem will be defined.

There are five different LED signals. They are listed below:

1.One flash, Boat wiring or battery voltage low,
2. Two flashes fan drawing more than ½ amp.
3. Three flashes, Units amperage too high, someone has tampered with refrigerant.
4. Four flashes, compressor under heavy starting load and can not reach 1850 rpm control speed in time.
5. Five flashes, compressor running under heavy load and module overheating.

Unfortunately trouble shooting LEDs are not installed on most units. I offer a kit that can be easily installed on the module.
There are installation instruction information at Danfoss and my web site as well as in my 12/24 volt refrigeration manual on Troubleshooting LEDs. If you would like the kit and step by step instructions with pictures, send $8 plus $4 shipping to me and I will mail you a complete kit. Or I will loan you a kit and return the $8 after you test it on your unit. This simple device can save you refrigeration down time and hopefully large repair costs. If you understand LED applications and do not need the kit I still provide free refrigeration help on my forum or by email. I can also help with free 3 and 4 pin Control module testing.

[witzgall]

Ssullivan has not been a member here for a few years....