Troubleshooting 12/24 volt Danfoss BD compressors.
If compressor runs continuously with less than desirable or no cooling
there is a refrigerant flow problem or loss of refrigerant or poor
condenser cooling. If at least 90% of evaporator’s surface area is
covered with a layer of frost no matter how thin refrigerant quality
and volume are correct. To confirm compressor runs continuously remove
thermostat wires from control module and place jumper wire across C
and T control module terminals.
If Danfoss compressor fails to run continuously this is caused 98% of
the time by an electrical problem.
There are two different series of Danfoss BD 12 volt compressors the
older fixed speed and the newer variable speed . If the refrigeration
unit is over 10 years old and has a Danfoss BD 2 or BD2.5 or BD3
compressor then it has the older fixed speed discontinued electronic 4
pin module. Troubleshooting Danfoss compressors with 4 pin modules
consists of the following steps:

1. All of these compressors have a 4 pin module connector and their
modules contain a replaceable fuse. If this fuse is blown there are
two reasons why either power wires to module are reversed or module
has an internal failure.

2. Check to see that there is actually power at the refrigerator
control module.

3. Place jumper wire across thermostat terminals on electronic module,
Compressor still does not run go to next step.

4. Disconnect black fan wire from electronic module, Compressor runs,
replace fan. Compressor still does not run after fan ground wire is
disconnected, go to next step.

5. Run correct size and correct polarity jumper wires direct from a
fully charged battery in order to bypass all boat’s wiring. Volt meter
readings are of no value when looking for voltage spikes. Compressor
still does not run electronic module needs to be removed and tested on
another unit. If there are no other units available to test your
module on I will test all 12 volt Danfoss control modules free except
for BD80 compressor modules. Email me for shipping address and
details.

Small 12/24 volt boat refrigeration units using Danfoss BD compressors
manufactured after 1996 will have a BD 35 or BD 50 variable speed
compressor with a troubleshooting computer chip built into control
module. This circuit makes them easier to find troubled area if
compressor fails to run. If this unit does not have this $2 LED
install one. Without the LED on these new units troubleshooting will
be the same as earlier 4 pin Danfoss BD compressors.

Trouble shooting LED will only flash if electronic module sees a
compressor problem. In each case problems of compressor’s failures to
run are identified by counting number of flashes of LED:
• No LED flashes would indicate either thermostat is open or no power
to module.
• One LED flash and a 4 second pause indicates a non Danfoss wiring
electrical resistance problem or low batteries. Because of module’s
sensitiveity to milliseconds of a voltage spike they cannot be
detected by a voltmeter. Solution is to bypass power wiring till
resistance problem is located.
• Two LED flashes indicates fan over current cutout. If fan circuit on
these variable speed compressors exceeds ½ amp compressor start up
will be aborted. This condition can be confirmed by disconnecting
Black fan wire at module, if compressor runs replace fan.
• Three LED flashes indicate excessive torque is required to start
compressor. This is commonly caused by turning compressor off and back
on too quickly or too much refrigerant or poor condenser cooling. Most
people jump to the conclusion that there is a mechanical rotor lock up
inside compressor and this is a mistake on Danfoss BD compressors.
• Four LED flashes indicate compressor motor not reaching sustained
controlling speed above 1,850 rpm quick enough.

If someone has tampered with refrigerant by connecting gauges to a
system letting air in or adding too much refrigerant can cause either
a Three or Four LED flashing signal. On water cooled Danfoss condenser
systems three and four LED signals are common when seawater gets into
refrigerant circuit.

"Richard Kollmann" wrote in message
...
Troubleshooting 12/24 volt Danfoss BD compressors.
(snipped)

Hi, Richard, and thanks for the note.

I've been all through the Danfoss literature, and many sources of what you
posted.

At this point, I'm reasonably sure that I have a leak in the "yellow" line
at the connection point, as the brass (copper?) part has what appears to be
some oil on it. The compressor runs, but no cooling happens - the lines to
and from the keel cooler as well as the compressor temperature are ambient.

I have a friend with a vacuum pump and the necessary adapter (he sez) to
attach a 134a can to my gauge set. However, I'm killing myself/going blind
trying to figure out which of the connection points (as they're not labeled
as such in the Danfoss literature, nearly everything related to a Bd50F and
101N0210 controller of which I believe I've read or looked at for
diagrammatic help) to which to connect my gauges/supply line.

Early on, we had a slight overcharge condition, likely due to the diligence
of the installation (SALT, my vendor, told me that the systems/lines were
slightly overcharged in production on the presumption that some would be
lost during connection make-ups). SALT suggested I open the top to the line
which is T'd into that yellow line, and cautiously vent a very little at a
time until my line from the freezer no longer had ice on it.

I did so, and all was well for some years, until just lately. New O-rings
are on the way from them, but I've discovered a small plastic bag which I
thought I'd remembered being attached to the compressor; it has three of
what I presume are the same O-rings in it. Therefore, one way or the other,
once I buy a can/dispenser setup, I think I should be ready to proceed to
replace that O-ring, evacuate, and recharge.

So, as I look at a keel-cooled Bd50F, 101n0210 controller with SSC attached,
setup, with the factory controller on the left, there's a heat-shrunk seal
on the top of the only other fitting I can see (there may be another in the
rear; I've not taken off my protective box - plywood with umpteen holes in
the top, and along the bottom sides, with the front, not likely to have any
contact with anything, open - in the engine room, yet) on the left top.

There's what I presume to be a capillary tube on the rear, which I also
presume will have a connection to a line, but I can't see it, as above (if
needed, I'll excavate the engine room to remove the box). It may have a
connection point, too.

So, can you tell me where to connect the high and low pressure lines, and
where to connect the supply (new 134a), to check it, as well as where to
connect the vacuum line before recharging? As well, should I be concerned
about the few drops of apparent oil loss? Their info strongly cautions
against charging with anything other than unadulterated 134a...

Also, my SSC has a trouble icon. Does this function as the LED for
blink-code information, would you know?

Thanks for checking in!

L8R

Skip

--
Morgan 461 #2
SV Flying Pig KI4MPC
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didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain

This started in the Shifting Sands thread; I've cc'd this to the
refrigeration discussion, as it's a bit afield from sanding :{))

Hi, and thanks to Wayne and Vic for enlightening me on stand-alone taps. I
can buy them at anywhere from 6 to 20 bux.

I do still have a problem about feeding the gauge set with it, as I have
only 3 hoses with my set; indeed, connecting to the second end of the center
line was my challenge. (The center has two males, one down, one out.)

The connections for the high and low pressure lines have a common air hose
connector - pull to allow/release ring - and a valve on them as well as on
the gauges, a curiosity to me as to why that rather than a direct hose
connection - but have the male open end on the hose-connect assembly/handle.
All three hoses are open on one end, and valve depressor on the other.

It was my recollection (it's been a while since I had to use one) that the
refill kits one buys have a made-up fitting at the can end, not a screw-off,
so I didn't twig to the possibility of a tap with just a male fitting coming
out.

I may have to buy a 4th hose (?) to make it work, or an adapter such as
Neal's picture showed, however, without extra hardware left somewhere...

As to the gas, it takes all of 6 ounces to fully charge our system, so
hunting for bargains on cans isn't a high priority :{)) When we bought our
car here and the AC failed after some work on other stuff, the mechanic who
screwed it up claimed he'd put gauges on it and found no pressure (instead,
the failure of the AC to run was his neglect of not putting on the high-temp
alarm connection back on when he did some other work); I bought a can with a
trigger and gauge; it read 150# (and was able to return it immediately from
outside AutoZone where I'd tested it), so I knew he was full of ****. As to
the WalMart can lead Neal provided, it has oil, and Danfoss is adamant about
putting in nothing other than straight gas, so I'd get the one without, if I
went that route for charging (still have the challenge of attaching the
pop-on end, of course; perhaps I'd have to buy an adapter such as his boat
pic showed for the other end of the ell-connection on the gauges - anyone
have a name for that fitting? It would be one which screws onto a 134a tap,
not a standard R12 [or, at least, the gauges suggest it's only for 134a, so
I presume there's a difference]).

Thanks again to all respondents. Tackling the handle seating in the freezer
lid today - once again, it broke out, as there isn't enough wood at the lip
to support the stress it endures, and the screws have stripped out more than
once, the latest before the current having been resolved by using 5-minute
double-tube syringe-type epoxy and shaping it with a chisel as it started to
set. I'm thinking of using our fairing compound this time (epoxy 2-part
mixup), as it will start setting at 4 hours, and be permanent in a day. When
it's green, it works easily, but is rock hard in the end; I'd drill and tap,
instead of using wood screws as in the priors. The 5-minute stuff wasn't
rock hard when I went to remove the broken bits...

Thanks for all the chime-ins. Even in this relatively limited forum (which
I vastly prefer as it's NNTP based rather than web interface), I get what I
come for!

L8R

Skip and crew

--
Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
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"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain

On Tue, 2 Aug 2011 08:11:16 -0400, "Flying Pig"
wrote:

I'm thinking of using our fairing compound this time (epoxy 2-part
mixup), as it will start setting at 4 hours, and be permanent in a day. When
it's green, it works easily, but is rock hard in the end; I'd drill and tap,
instead of using wood screws as in the priors. The 5-minute stuff wasn't
rock hard when I went to remove the broken bits...

Fairing compound is not strong enough for that application. I've had
good luck using J-B Weld which is a filled and thickened epoxy, very
tough stuff, almost as strong as metal. It's easy to use and cures
relatively quickly.

I'm having a difficult time visualizing your issue with the hose and
gauge set. A typical gauge set comes with three hoses: blue, red and
yellow. Blue is for the low pressure side, red for high, and yellow
is in the middle and goes to your can tap adapter or vacuum pump. The
blue and red hoses may be terminated with either quick connects or
female screw-on connectors. It sounds like your compressor is set up
for quick connects but I can't be sure from your description. You
need to get hoses which match the connectors on your compressor.

You probably already know this but it's important to purge the air out
of the hoses before filling your system.

Hi, Wayne,

In case I've not said so before, I'm very appreciative of your (and others')
thoughtful input...


"Wayne B" wrote in message
...
On Tue, 2 Aug 2011 08:11:16 -0400, "Flying Pig"
wrote:

I'm thinking of using our fairing compound this time (epoxy 2-part
mixup), as it will start setting at 4 hours, and be permanent in a day.
When
it's green, it works easily, but is rock hard in the end; I'd drill and
tap,
instead of using wood screws as in the priors. The 5-minute stuff wasn't
rock hard when I went to remove the broken bits...

Fairing compound is not strong enough for that application. I've had
good luck using J-B Weld which is a filled and thickened epoxy, very
tough stuff, almost as strong as metal. It's easy to use and cures
relatively quickly.

Another (the one with the vacuum pump and adapters I'll borrow, the same guy
who's been here for 10 years in the interview thread) cruiser said the same,
but recommended Cabosil. I think I like JB just for its simplicity. He
also suggested a receiver for a machine screw bedded into it, which might
lessen the likelihood of a recurrence. As I'll be adding some gasketing, and
it's a top-load, without the "usual" lever-arm reefer latch (prevents a flat
surface which we need on the countertop), it will take even more effort than
it does currently to close. We have to set it, with the latch already
depressed in the receiver lip, and give it a forceful whack with both fists
to make it seat. The current failure was a matter of having something in
the freezer preventing the latch from engaging the lip; whacking it put all
the force on the tongue, forcing the lift which broke my earlier repair...


I'm having a difficult time visualizing your issue with the hose and
gauge set. A typical gauge set comes with three hoses: blue, red and
yellow. Blue is for the low pressure side, red for high, and yellow
is in the middle and goes to your can tap adapter or vacuum pump. The
blue and red hoses may be terminated with either quick connects or
female screw-on connectors. It sounds like your compressor is set up
for quick connects but I can't be sure from your description. You
need to get hoses which match the connectors on your compressor.

I have those three; they are double-ended females, the open end goes on the
gauge set and the schrader-depressor end on the compressor.

My problem is getting the can connected to the yellow hose ell...


You probably already know this but it's important to purge the air out
of the hoses before filling your system.

Yup - a brief squirt through them should accomplish that. My buddy's coming
by today, so I should have the charging (or, if not, identified it as some
other problem) done today...

Thanks again.

L8R

Skip, with the new metal going on the bow roller cage today...


--
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SV Flying Pig KI4MPC
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"Believe me, my young friend, there is *nothing*-absolutely nothing-half so
much worth doing as simply messing, messing-about-in-boats; messing about in
boats-or *with* boats.

In or out of 'em, it doesn't matter. Nothing seems really to matter, that's
the charm of it.

Whether you get away, or whether you don't; whether you arrive at your
destination or whether you reach somewhere else, or whether you never get
anywhere at all, you're always busy, and you never do anything in
particular; and when you've done it there's always something else to do, and
you can do it if you like, but you'd much better not."

Skip, Unfortunately all manufacturers of boat icebox conversion units
have some items in their designs that cause unwanted problems. Pre-
charged refrigerant lines have always come with O rings to prevent
refrigerant loss during assembly. Ounce torque down a metal seal
permanently prevents line connector leakage but Frigoboat relies on O
ring seals only to retain refrigerant. There are many applications
where O rings are used to prevent leaks. Now you are finding out why
spare O rings come with new Frigoboat units and also why at boat shows
they demonstrate how to change Orings. What you must find out for
yourself is the difficulty in re-commissioning systems after replacing
a refrigerant line O ring. When reliability and safety is demanded
from O rings shelf life of new rings is limited to one year. I read on
another forum where there was a discussion about replacing these
Frigoboat O rings every five years. My guess is that only one out of
ten refrigeration service technicians could add the correct amount of
refrigerant to your system.

Frigoboat’s refrigerant flow lines on keel cooler systems are simple.
There are three lines connected to compressor two on dome top and one
coming out of side. Line coming out of compressor’s side below welded
dome goes to keel cooler. Line out of other side of keel cooler runs
to evaporator. Return line from evaporator connects to one of the
lines coming out of compressor dome. Other line out of compressor dome
is short with the only refrigerant servicing connection on this system
There are three line connectors with O rings and no high pressure
servicing connection on a standard Frigoboat unit. Some installations
have optional line extensions that add more line connectors.

Yes there is a trouble shooting LED on the Smart Speed Control and it
will only flash when electronic control module senses an electrical
problem. Low cooling do to refrigerant loss will NOT trigger a signal
from troubleshooting LED.

Hi, Richard,

Thanks for the erudition and education!

So, if I read your stuff (clipped for brevity) correctly, the left side
nipple on the top of the dome is where I'd put new gas after evacuation. Is
that also where I'd evacuate it?

The one out of the side under the dome connects to the point which leaks,
and has a T'd connection point on it. That's the one I was instructed early
on to vent the slight overcharge from.

I (think I) understand from your tutorial that there is no real means of the
typical testing setup on my unit - no place to connect to high and low
side - just for evacuation and gassinng?

Thanks again for your assistance.

L8R

Skip

--
Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.yahoo.com/group/TheFlyingPigLog
and/or http://groups.google.com/group/flyingpiglog

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain

On Tue, 2 Aug 2011 08:11:16 -0400, "Flying Pig"
wrote:



As to the gas, it takes all of 6 ounces to fully charge our system, so
hunting for bargains on cans isn't a high priority :{)) When we bought our
car here and the AC failed after some work on other stuff, the mechanic who
screwed it up claimed he'd put gauges on it and found no pressure (instead,
the failure of the AC to run was his neglect of not putting on the high-temp
alarm connection back on when he did some other work); I bought a can with a
trigger and gauge; it read 150# (and was able to return it immediately from
outside AutoZone where I'd tested it), so I knew he was full of ****. As to
the WalMart can lead Neal provided, it has oil, and Danfoss is adamant about
putting in nothing other than straight gas, so I'd get the one without, if I
went that route for charging (still have the challenge of attaching the
pop-on end, of course; perhaps I'd have to buy an adapter such as his boat
pic showed for the other end of the ell-connection on the gauges - anyone
have a name for that fitting? It would be one which screws onto a 134a tap,
not a standard R12 [or, at least, the gauges suggest it's only for 134a, so
I presume there's a difference]).


I can't venture anything more because I've only done automobile AC.
As I recall from having a R12 to 134A conversion done they use
different connectors.
My gauge manifold sets are post-R12.
Good you take only 6 ounces.
Most auto systems I've worked on take close to 3 lbs.
When one goes bad with a slow leak you end up losing a few cans before
all is said and done.
I like to have about 6 cans available.
Besides that I inject dye and oil separately as needed, and don't want
any "stop leak" products in the system.
One time an auto store I went into had only adulterated 134A.

--Vic

"Gogarty" wrote in message
...
How come Wilbur has not weighed in on this thread?

So far as I know the Danfoss compressors for marine fridges have only one
service port on the low side. When new it is sealed with a cap and black
gloop. Remove the gloop and the cap and you find an R34a-specific snap
coupling which mates to your vacuuum pump or charging manifold. I managed
to
set things up without a manifold or guages using a fitting that allows me
to
inject refrigerant directly into the low side port. You can vent excess
there
too with an Allen wrench pushing on the valve. Mine has been running
flawlessly (knock, knock) since I evacuated it and carefully injected
refrigerant using the frost line as a guide.




Wilbur has weighed in a time or two. . . Even posted a link to a photograph
of the r134a adapter for car A/C cans.

My Danfoss compressor has two service ports. One to connect the high
pressure gauge and one to connect the low pressure gauge. The port on top is
the suction or low pressure. This is where I add refrigerant. The port below
is the high pressure or compressed gas port. But, I don't bother with the
high pressure reading since there is no way to adjust it independently of
the low pressure side. Mine works great with seven to eight psi on the low
side. I haven't a clue what that amounts to on the high side. If I try to
add more than ten psi on the low side the thing won't keep running. It
cycles off and on as there is some safety circuit that turns it off so it
doesn't become damaged. It also draws too much amperage above 8psi. I like
to see it draw between 3-4 amps. It runs smoothly and quietly then. I like
to see the frost line inside the ice box as anything being cooled outside
the box is wasted effort and energy.

The electrical tape repair is still going strong. No leaks to date.


Wilbur Hubbard

On 8/1/2011 7:27 AM, Richard Kollmann wrote:
Troubleshooting 12/24 volt Danfoss BD compressors.
If compressor runs continuously with less than desirable or no cooling
there is a refrigerant flow problem or loss of refrigerant or poor
condenser cooling. If at least 90% of evaporator’s surface area is


Lots of erudition, and I didn't read all, but did anyone mention the size of
whatever hole supplies cooling air to the refrigerator? I had same problem as
you when we got our trawler. Looked and the hole to the outside was 4 sq.
inches. Enlarged that and the problem went away.

gm