Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 01-09-2020, 23:32   #1
Registered User

Join Date: Jun 2018
Location: Greece
Boat: Bavaria 46 (2007)
Posts: 131
Issues with Danfoss Compressor

Hi guys,

I have read a number of the Danfoss Troubleshooting posts and I think I know what to do but wanted some advice before I did it.

I have an issue where the compressor (BD35F) is failing to run in the night. You hear it try to start and it shuts down and continues this start/stop loop. There is voltage in the batteries (12.5, 12.6), the batteries are brand new and my freezer which also uses a similar compressor runs fine.

This only happens at night as when my solar panels are charging the batteries, there are no issues with it.

I suspect that I need to change the cable wiring as when the voltage is lower at night, the losses are too great to run the compressor.

Is there anything else I should be looking at or considering?

Thanks.
lawrence_craig is offline   Reply With Quote
Old 02-09-2020, 00:55   #2
Registered User

Join Date: Jun 2018
Location: Greece
Boat: Bavaria 46 (2007)
Posts: 131
Re: Issues with Danfoss Compressor

Quote:
Originally Posted by lawrence_craig View Post
Hi guys,

I have read a number of the Danfoss Troubleshooting posts and I think I know what to do but wanted some advice before I did it.

I have an issue where the compressor (BD35F) is failing to run in the night. You hear it try to start and it shuts down and continues this start/stop loop. There is voltage in the batteries (12.5, 12.6), the batteries are brand new and my freezer which also uses a similar compressor runs fine.

This only happens at night as when my solar panels are charging the batteries, there are no issues with it.

I suspect that I need to change the cable wiring as when the voltage is lower at night, the losses are too great to run the compressor.

Is there anything else I should be looking at or considering?

Thanks.
Unable to edit the above. I am having issues with it during the day now. I currently have 12.7V on the battery yet the compressor is definitely going off on low voltage (<10.7V) when it ties to run.

What I don't understand, which someone might be able to help me with, is that I didn't previously have this issue so what causes the degradation? Thanks in advanced.
lawrence_craig is offline   Reply With Quote
Old 02-09-2020, 02:42   #3
Moderator
 
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 14,085
Images: 14
Re: Issues with Danfoss Compressor

There is comparatively high start up load when the compressor tries to start. So guessing that either the connections have some corrosion or the wiring is too small for the wire run resulting in a voltage drop.

Had a similar problem on a previous boat, so when I wired up our conversion kit from cool box to fridge on the yacht, I used 4.5mm wire for both the pos and neg cables. This has worked well for the past 14 years.

Trace the wires from the fridge back to the switches and on to the bus bars or batteries to make sure they are substantial enough for all the loads that are being used, not just the fridge.

There is a calculator half way down this page which might be useful.

https://www.12voltplanet.co.uk/cable...selection.html
Pete7 is offline   Reply With Quote
Old 02-09-2020, 03:25   #4
Registered User

Join Date: May 2020
Posts: 6
Re: Issues with Danfoss Compressor

If you say "definitely going off on low voltage" - did you connect the troubleshooting LED to + and D/I or what makes you so sure?


To be sure I would connect the LED and also measure voltage at the compressor. Also measure current if you can.


A quick measure to reduce current is to reduce the RPMs by removing the resistor between the terminals C and T (see the documentation at https://assets.danfoss.com/documents/DOC147286416541/DOC147286416541.pdf )
barnab is offline   Reply With Quote
Old 02-09-2020, 08:44   #5
Registered User

Join Date: Apr 2012
Location: Currently in Spain
Boat: Island Packet 420
Posts: 344
Re: Issues with Danfoss Compressor

Is it possible that your batteries are losing some of their capacity? I had this happen to me, the voltage was plenty high, but as soon as there was a load, the voltage drops and won't run something like a fridge.
sailing_gal is offline   Reply With Quote
Old 02-09-2020, 08:57   #6
Registered User

Join Date: Sep 2017
Location: Langley, WA
Boat: Nordic 44
Posts: 1,344
Re: Issues with Danfoss Compressor

Measure the voltage at the controller as it tries to start up. That is the test that will prove if it is the wiring.. If it is getting progressively worse it is probably a corroded connection somewhere. Just removing and re-attaching the wiring may be a temporary solution.
stormalong is offline   Reply With Quote
Old 02-09-2020, 09:06   #7
Registered User

Join Date: Sep 2018
Posts: 45
Re: Issues with Danfoss Compressor

I had issues with one of these units and on two occasions is turned out to be the “black box” controller, which is attached to the compressor via a multi-pin connector. If possible, find a refrigeration techie who has a used / spare one on the shelf, and you can swap it out for a test.

myageofsail.com
psp2psp2 is offline   Reply With Quote
Old 02-09-2020, 09:21   #8
Registered User

Join Date: Jul 2011
Location: Montreal/Fort Lauderdale
Boat: Carver Voyager 5300
Posts: 1
Re: Issues with Danfoss Compressor

I had that problem on my Beneteau. So to test the connection, I simply connected the compressor directly to the battery bank with an on-line fuse. It solved the problem, and I kept it that way for many years after. I used the thermostat to shut it down.
cpasquin is offline   Reply With Quote
Old 02-09-2020, 09:38   #9
Registered User

Join Date: Jan 2017
Location: San Diego
Boat: Kelly Peterson 46
Posts: 86
Re: Issues with Danfoss Compressor

I have been doing lots of monitoring of our compressors as part of some electronics projects. You shouldn’t see a spike over 6 amps and run between 2 and 5 amps. That shouldn’t drain even very aged batteries. I would start by putting a voltmeter on the compressor and measure the startup voltage. Better multimeters can capture spikes. The led is also a great idea if you have one laying around.
All your symptoms would lead me to believe you have a corrosion issue.
bradfordharley is offline   Reply With Quote
Old 02-09-2020, 13:46   #10
Registered User

Join Date: Jun 2018
Location: Greece
Boat: Bavaria 46 (2007)
Posts: 131
Re: Issues with Danfoss Compressor

Thanks for your replies so far.

Reading the voltage at the compressor, before start up it reads the same voltage as at the battery (12.6V). Then when the compressor tries to start, it dips below the 10.7V level before the compressor gets up to speed which I believe is the auto shut off.
lawrence_craig is offline   Reply With Quote
Old 02-09-2020, 14:03   #11
running down a dream

Join Date: Mar 2006
Location: somewhere in the deep south
Boat: CD30 MKII
Posts: 2,192
Images: 6
Send a message via Yahoo to gonesail
Re: Issues with Danfoss Compressor

one of the problems I had was as simple as cutting an inch off the end of the 12v power wire and exposing fresh wire .. then securing back into the unit.
__________________
some of the best times of my life were spent on a boat. it just took a long time to realize it

gonesail is offline   Reply With Quote
Old 02-09-2020, 14:32   #12
Registered User
 
CarinaPDX's Avatar

Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 2,611
Re: Issues with Danfoss Compressor

Drawing 6A from your battery shouldn't cause a 2V drop - if that is the case at the battery terminals your battery is toast. More likely there is resistance in the wiring from corrosion causing the voltage drop. Check connections first.

Greg
CarinaPDX is offline   Reply With Quote
Old 02-09-2020, 15:30   #13
Registered User
 
hzcruiser's Avatar

Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 647
Re: Issues with Danfoss Compressor

As mentioned, your best bet is to check the wiring and connectors first.
__________________
Fair winds,
heinz
hzcruiser is offline   Reply With Quote
Old 02-09-2020, 22:47   #14
Registered User

Join Date: Aug 2007
Location: Adelaide, South Australia, sailing in the Med.
Boat: Beneteau, Oceanis 50
Posts: 837
Re: Issues with Danfoss Compressor

Quote:
Originally Posted by lawrence_craig View Post
Unable to edit the above. I am having issues with it during the day now. I currently have 12.7V on the battery yet the compressor is definitely going off on low voltage (<10.7V) when it ties to run.

What I don't understand, which someone might be able to help me with, is that I didn't previously have this issue so what causes the degradation? Thanks in advanced.
Unless the compressor is developing a fault, then it is voltage to the compressor. With the high in-rush current at start up, the voltage is dropping too low, and it gives up. Put a meter across the terminals right at the compressor (on the compressor terminals, not the connectors to the terminals) and you will know if this the problem or not. Not running, you should see 12.7V or so, then look at what happens when the compressor cuts in (or try's to). That will tell you the problem. Then look for connection issues - could be right where the wiring goes to the compressor - could be right back at the distribution.

Or - it could be your batteries starting to fail, and not handling the in-rush current (but then I would have thought you would notice this elsewhere, such as your fridge).

I hope that helps.

David
David B is offline   Reply With Quote
Old 02-09-2020, 23:18   #15
Registered User
 
Uncle Bob's Avatar

Join Date: May 2010
Location: Sydney Australia
Boat: Fisher pilothouse sloop 32'
Posts: 1,945
Re: Issues with Danfoss Compressor

I am surprised that our galloping guru hasn't jumped in to offer words of wisdom, but my guess would be in the power supply camp, check all connections and cable condition/size.
__________________
Rob aka Uncle Bob Sydney Australia.

Life is 10% the cards you are dealt, 90% how you play em
Uncle Bob is online now   Reply With Quote
Reply

Tags
compressor

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Danfoss Compressor 'Bumps' but then Doesn't Run SV Liberty Plumbing Systems and Fixtures 24 22-12-2015 23:33
240vac Danfoss Compressor to 12vdc Danfoss cat man do Plumbing Systems and Fixtures 15 30-05-2013 13:13
Question Regarding Danfoss Compressor cburger Construction, Maintenance & Refit 4 02-05-2011 05:57
For Sale: Portable Fridge/ Freezer, Danfoss Compressor Boatguy30 Classifieds Archive 3 13-12-2010 18:31
Wanted: Danfoss compressor controller sorino99 Classifieds Archive 4 27-10-2008 09:03

Advertise Here


All times are GMT -7. The time now is 17:23.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.