Cruisers Forum
 


Join CruisersForum Today

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 15-12-2016, 18:49   #1
Registered User

Join Date: Dec 2012
Location: Grenada
Boat: Albin Vega 27'
Posts: 9
Bypassing Danfoss Controller 3-pin compressor

Hi everyone,

I hope someone with expertise or experience can help answer this question instead of just getting a bunch of stabs in the dark.

The controller for my Danfoss 35/50 compressor is out. It should be possible, in theory, to directly connect power source to compressor via 3-pins on compressor and wire in an external thermostat to +. The compressor would run at full RPM (not variable as it would with the controller) when on, but other than that, I don't see why this wouldn't be possible. I just have to figure out which pin on the compressor in what...

Anyone ever try this?
__________________

Jon Phillips is offline   Reply With Quote
Old 15-12-2016, 19:16   #2
Senior Cruiser
 
sneuman's Avatar

Cruisers Forum Supporter

Join Date: May 2003
Location: Jamaica
Boat: Tayana 37 Cutter
Posts: 3,169
Images: 37
Re: Bypassing Danfoss Controller 3-pin compressor

Good question. I am in precisely the same situation.
__________________

__________________
Voyage of Symbiosis: http://svsymbiosis.blogspot.com/
sneuman is offline   Reply With Quote
Old 15-12-2016, 19:17   #3
Registered User

Join Date: Jul 2012
Boat: Tayana 58 DS
Posts: 727
Re: Bypassing Danfoss Controller 3-pin compressor

I believe the Danfoss uses a brushless Dc motor. If so, it will require both a wire and a motor controller. The controller does some signal processing, usually Kalman filtering, to rotate the field in the compressor's motor. For almost everyone, it is impractical to try to design your own. If you like to tinker you could make a project out of it, but I'd rather go sailing.
,

Sent from my SM-G930V using Cruisers Sailing Forum mobile app
accomplice is offline   Reply With Quote
Old 15-12-2016, 19:24   #4
Registered User

Join Date: Jan 2014
Location: Panama City FL
Boat: Island Packet 32 Keel/CB
Posts: 423
Re: Bypassing Danfoss Controller 3-pin compressor

Afraid you are SOL. The motor is 3 phase AC and one of the functions of the motor controller is to convert DC to 3 phase AC. Richard K was offering a repair service once if my memory is correct (often it aint). RPARTS if they are still around also had the controllers.

If you are running the compressor on maximum speed a small blower is suggested to keep the controller from over heating.
Frankly is offline   Reply With Quote
Old 15-12-2016, 19:51   #5
Registered User

Join Date: Dec 2012
Location: Grenada
Boat: Albin Vega 27'
Posts: 9
Re: Bypassing Danfoss Controller 3-pin compressor

Thanks Guys,

Already ordered the controller and will put it in. Was more of a thought experiment as I couldn't find the electrical info for the compressor online. Without claiming any expertise with these compressor myself, I'm actually suprised to hear the motor runs 3 phase AC. If you look at the self-contained dometic/waeco units on Amazon they often sell with AC to DC converters... In these applications then, AC is being converted to DC just to be converted back again. Anywho, thanks for the info =)

Cheers,
Jon
Jon Phillips is offline   Reply With Quote
Old 15-12-2016, 20:45   #6
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 6,679
Re: Bypassing Danfoss Controller 3-pin compressor

What comes out of the controller is actually 3 phases of pulsed DC.
Each pulse is 120 degrees out of phase from the next one.
The motor acts as if it's AC.
__________________
One should try to "Die Young" as old as possible.
senormechanico is offline   Reply With Quote
Old 15-12-2016, 20:58   #7
Registered User

Join Date: Dec 2012
Location: Grenada
Boat: Albin Vega 27'
Posts: 9
Re: Bypassing Danfoss Controller 3-pin compressor

Thanks again,

Out of curiosity, what would be the protocol to bypass the thermostat to troubleshoot? I have a hunch that the thermostat may be suspect too
Jon Phillips is offline   Reply With Quote
Old 15-12-2016, 21:30   #8
Registered User

Join Date: Apr 2011
Posts: 425
Re: Bypassing Danfoss Controller 3-pin compressor

On mine I followed the wires from the thermostat and just connect those two posts with a short piece of wire. That duplicates the thermostat calling for cooling. (turns it on) . You might want to google Kollman Refrigeration. He has retired ( more than once) and has put up trouble shooting guides on his web site.
maine50 is offline   Reply With Quote
Old 16-12-2016, 04:23   #9
Registered User

Join Date: Aug 2015
Posts: 460
Re: Bypassing Danfoss Controller 3-pin compressor

Thermostat bypass: join C to T.
Note that this also bypasses any speed control (compressor runs at slowest speed).

http://files.danfoss.com/TechnicalIn...aWvWD3nL7YNM5A
boatbod is offline   Reply With Quote
Old 16-12-2016, 08:55   #10
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 7,792
Re: Bypassing Danfoss Controller 3-pin compressor

Quote:
Originally Posted by Frankly View Post
RPARTS if they are still around also had the controllers.
They were as of August 2016. Great folks, quick shipping & delivery. Had exactly what I needed to replace my 29 year old module. Been working fine ever since.

Adler Barbour Replacement Electronic Modules

If you're indeed in Grenada, this may still help. If your module is truly fried, like mine was, bypasses will only prove that for you. You still need a long term solution.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 16-12-2016, 09:06   #11
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 26,328
Re: Bypassing Danfoss Controller 3-pin compressor

Quote:
Originally Posted by senormechanico View Post
What comes out of the controller is actually 3 phases of pulsed DC.
Each pulse is 120 degrees out of phase from the next one.
The motor acts as if it's AC.

I believe this to be correct, motor may in fact be three phase AC, but pulsed DC emulates AC

Quote:
Originally Posted by boatbod View Post
Thermostat bypass: join C to T.
Note that this also bypasses any speed control (compressor runs at slowest speed).

http://files.danfoss.com/TechnicalIn...aWvWD3nL7YNM5A
This is also correct, I have done it myself to get around a hard start situation
a64pilot is offline   Reply With Quote
Old 16-12-2016, 09:22   #12
Registered User
 
Dougtiff's Avatar

Join Date: Jul 2015
Location: San Rafael, Ca.
Boat: Gaff rigged Ketch[Spray]37' on deck
Posts: 349
Re: Bypassing Danfoss Controller 3-pin compressor

The question is why did the module fail, they are expensive and replacing the blown one, could do the same to the replacement, i don't have a answer the it, i do know the older modules would fail due to the hard start over time, unlike the newer design that has a soft start and is not being slammed with full voltage.
Dougtiff is offline   Reply With Quote
Old 16-12-2016, 10:00   #13
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 11,173
Re: Bypassing Danfoss Controller 3-pin compressor

Quote:
Originally Posted by maine50 View Post
On mine I followed the wires from the thermostat and just connect those two posts with a short piece of wire. That duplicates the thermostat calling for cooling. (turns it on) . You might want to google Kollman Refrigeration. He has retired ( more than once) and has put up trouble shooting guides on his web site.
Richard also sells a very good book on his web site too.

There usred to also be lots of good troubleshooting info on the Danfoss sight too. Not sure if its still there after the change in ownership.
belizesailor is offline   Reply With Quote
Old 16-12-2016, 10:02   #14
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 11,173
Re: Bypassing Danfoss Controller 3-pin compressor

Quote:
Originally Posted by senormechanico View Post
What comes out of the controller is actually 3 phases of pulsed DC.
Each pulse is 120 degrees out of phase from the next one.
The motor acts as if it's AC.
Interesting. Ive often wondered about that, but found no tech detail. Pulsed/phased DC makes more sense to me than inverting.

Have any reference for this?
belizesailor is offline   Reply With Quote
Old 16-12-2016, 10:21   #15
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 11,173
Re: Bypassing Danfoss Controller 3-pin compressor

Quote:
Originally Posted by Dougtiff View Post
The question is why did the module fail, they are expensive and replacing the blown one, could do the same to the replacement, i don't have a answer the it, i do know the older modules would fail due to the hard start over time, unlike the newer design that has a soft start and is not being slammed with full voltage.
The electronics module, or thermostat, are the most common failures...the compressors are pretty bullet proof. Heat, moisture, vibration all take their toll.
__________________

belizesailor is offline   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 22:33
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 17:31
Wanted: Danfoss compressor controller sorino99 Classifieds Archive 4 27-10-2008 09:03



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.