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Danfoss BD50F 1220 Charging

16K views 31 replies 6 participants last post by  aeventyr60 
#1 ·

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#2 ·
is the silver part a cap or female fitting? if a cap then the charge hose should fit on the male fitting and it would have a schrader valve in the male fitting to keep the charge in when the hose is removed. you need a threaded hose like the one in the link not the automotive push on type
 
#4 · (Edited)
Some concerns here.
After about 2009 many Danfoss BD compressors used 404 refrigerant, not 134a.

Before about 2009 the 134a was applied/filled by weight of refrigerant, not pressure (gages); and used ONLY about 5-6 ounces (weight) of 134a. So, if you are refilling and if 134a is appropriate for your unit, depressurize the unit, then attach the 134a and 'pigtail' to the LOW pressure side connection (should have a MALE connector with "schrader valve" in the center of the connector). If you have a digital 'postal scale' put the can of 134a onto the postal scale and deliver only 5-6 oz. (weight).
If you don't have an electronic digital postal scale ... fully depressurize, attach the pig-tale and SLOWLY add the 134a, ... until you 'feel' the side of the (12oz.) can to be 'half empty' - you will 'feel' that the zone of 'cold' on the side of the can will be noticeable from the zone of 'not cold' at about half way up the side of the VERTICAL can of 134a.
If the unit was originally filled with 134a, the low pressure connection will be the standard MALE 'automotive' type connector.

Other - if your Danfoss originally had a cover/containment to direct air flow through the 'coil', that cover/containment must be in place when you refill (with the unit operating). You should use 'cardboard and tape' to close any 'holes' in the 'containment' in the cardboard .... so that the air flow properly flows through the 'coil'.
 

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#5 ·
Rich 404? 404A? news to me! 404A is usually found in ice makers (low temp)

Dev, connectors on the hose ends are actually1/4 and 3/8 flare with a shrader valve depressing insert. The othe,r that you find on automotive is a quick connect type something like on air hose but not really the same.

DON'T mess with it! but it looks like someone already has (most don't have a service port from the factory. )
 
#6 · (Edited)
Rich 404? 404A? news to me! 404A is usually found in ice makers (low temp)

Dev, connectors on the hose ends are actually1/4 and 3/8 flare with a shrader valve depressing insert. The othe,r that you find on automotive is a quick connect type something like on air hose but not really the same.

DON'T mess with it! but it looks like someone already has (most don't have a service port from the factory. )
Looks like his BD is 'missing' the Suction Gage Port that one finds on most Danfoss units used in marine applications ??????? see my attachment.
Ive seen two with 404a (!!!??) Seafrost BDxpx used for freezer only applications (http://www.seafrost.com/BD.html) ... but usually the suction port is tagged. Most common 134a units are usually (or should be) tagged with the ID of the correct refrigerant.
 
#7 ·
It is tagged : 134A on the picture.

http://files.danfoss.com/TechnicalI...d50f_r134a_12-24vdc_06-2011_dehced100e602.pdf

The electronic unit : 101N0230.
I look a bit online and the symptoms really looks like low on refrigerant. I am just starting to look into it, and wanted to order the parts before going back to the boat this week end.
Someone in a thread said you could find adapters to those schrader valves in automative stores as well.
 
#11 ·
Here are the notes I found online that might help me:
Does that sound relevant ?

Recharge Your Refrigerator - Sail Magazine
Kollmann Marine

Things to remember before connecting gauges and servicing:
1. Purge refrigerant through gauge set to remove air and moisture.
2. Stop compressor before connecting gauges, as it may be running in a vacuum.
3. Everything in the system including the ice box needs to be 70˚ F. or above.
After the compressor is started the suction pressure will drop and stabilize this may take 10 minutes. Then warm the box, A setting of 6 to 8 psi would be the correct charge for 134a refrigerant. If at 10 to 20 minutes this pressure is low, add a small amount of refrigerant. Yes small amount, and then wait till it seeks a new stabilized pressure before adding more. If the system wad over charged, and yours is not, the pressure would be higher than 10 psi. The exception to these pressures would be if you have AB's large 15 inch evaporator then the pressures should be 2 psi higher. A small overcharge of ½ ounce or more (15 Grams)of refrigerant will cause an increase of daily amp-hrs used.
If you are unable to adjust the refrigerant level in the first 20 minutes, stop and let the evaporator warm back up to 70˚F. After 20 minutes, the suction pressure will automatically adjust down to lower temperatures and lower flows as the plate and box cools. Use pressures for servicing only in a time window between 10 and 20 minutes with a warm box. Fine tuning later is done by setting frost line (upper heat), confining it to evaporator.
After removing the gauge set be sure to replace the sealing cap with its seal still inside on the service fitting. Common slow refrigerant leaks are caused by poor sealing of these caps.

Answer: am assuming, if you are adding 134a refrigerant, that your compressor is either a
BD3 or BD50 and not a BD2.5. Turn compressor off first. Purge air from
hoses then connect refrigerant hose to suction port. With bottle upright, to
add gas not liquid, allow only 2 ounces of refrigerant to enter system, then
shut off bottle and start compressor. The quickest way to charge system
correctly is to use an ammeter in power wire and very very very slowly add
refrigerant until amperage reaches 5 amps. As evaporator cools amperage
will be less than 5 but never above 5.5 amps. Then from this point on ignore
amperage and run unit for 2 hours checking frost on surface area of
evaporator. Your unit will be charged correctly when the evaporator's surface
area has frost covering 90 to 100% of its surface and no frost on return
line toward compressor. If frost area is less than 90% add refrigerant. Your
unit will hold from 3 to 5 ounces of refrigerant. With 1/2 ounce too much
refrigerant system will deliver poor performance. If you do not have my
12/24 volt refrigeration manual see if one of the other boaters has one you
can use. The above method of adding refrigerant will not harm your unit and the box will get cold.
 
#12 ·
Rich Kollmann is 'the' guru for marine refrigeration .... follow what applies to your system exactly.

The link that you provided indicates in that data that YOUR system probably needs 10 to 12 oz. (weight) installed. Use the technique that I posted (postal scale or feeling the side of the freon container, etc.) No where in that data sheet is there a 'suction port' !!!??? ... so you may have to ask the mfg. exactly where this version Danfoss is filled (with ease).
 
#13 ·
Dev what is the make /model of the unit ? not the compressor.
How old is it?
What are the "symptoms"???
What tools do you have? Guessing you don't have HVAC tools
40+ years HVAC here I should be able to help you IF; You provide info.

Pics of your unit and the name plate is a start
 
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#14 ·
Symptoms : not cooling.
Turns fine, warm up, I put the gauge and while the compressor is running I have 0 PSI pressure.
looks like this is exactly this one : https://www.waveinn.com/nautical-fi...3LecK9UKWsGkCgYUZHlwkBoCcjnw_wcB&gclsrc=aw.ds

Don't know how old it is, came with the boat, never worked, never tried to get it to work in 2 years, but it seems clean and almost new as far as I can tell.
I found the adapter in Auto store.

I did not try yet to charge it.
 

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#15 ·
Btw, Pictures are on the first post.

I like this method:


Turn the thermostat knob to its middle position, about "3" or "4". The

fan should come on and a few seconds later the compressor should

start. When the compressor starts, the suction pressure gauge (blue)

reading will go down.

When the gauge reading approaches zero, open the service manifold

valve briefly to allow more refrigerant vapor to enter the system.

Keep regulating the valve to try to maintain about 10 psig on the

gauge. Add refrigerant slowly (a few seconds at a time) and allow

the pressure to stabilize before adding more. Only add refrigerant when

the pressure is below 10 psig.

At some point, frost will begin to form and slowly

spread around the evaporator

Keep adding refrigerant slowly until about 1/4 of the evaporator is

frosted. The low-pressure reading should be about 8 to 10 psig when

the evaporator is 1/4 frosted.

Allow the system to run until the thermostat turns it off. The

evaporator should be fully frosted, and the suction pressure reading

should be around 4 to 6 psig.
 
#16 · (Edited)
There is air in the manifold and hose, it needs to be purged from the hose or it will be drawn into the low side. A 14oz can is about 2-3 times more then is needed. 134 systems need to run much longer to stabilize. If you don't weigh it in don't dump in the contents.

like you posted add very little, watch wait and feel the frost line as it starts to chill the whole evaporator,

don't add so much the the compressor and line get cold, if you get it right, when the box is cold the low pressure should be 3-8 lbs. It does vary and will be much higher with a "warm" box
 
#18 ·
Yes that works. Also look for leaks where the tubes bend around corners or go through holes cut in bulkhead. If those tubes touch anything they will chafe trough and spring a leak. If you have the white coated aluminum tubes then look for breaks in the white coating. You might get away patching said leaks with some kind of liguid metal. Otherwise a new evaporator will be in your future.
 
#19 ·
More often then not the cap and Schrader leak.

Also just removing the charging hose on small units can get right back to a low refrigerant charge.

It's a very rare occurrence, but the electric pin connectors on the compressor can leak.
 
#20 ·
Mixed results so far.
I managed to maintain the pressure to 8-10 PSI and get 1/3" of the plate frozen.
As a test I disconnected everything, let the box warm and tried again.
It seems the pressure was back to be very low.

How long does that takes for the pressure to be back to 'running' state ? It seems that 10 minutes is a good start.
Stupid question. When trying to get the plate frozen and play to keep the pressure between 8-10psi , should I keep the ice box opened or closed ?
 
#23 · (Edited)
Nope, go about it this way.

let it run an hour or more. box open or closed. then check the plate.

DON'T PLAY with the low pressure! You cannot charge such a small system by gauge pressure, every time you add 134, it has to run long enough to let the compressor do it's job by pulling from the coil.

If the charge is close, in an hour or so the plate will slowly get cold. If over charged the compressor may even get cold. (not good)

if the capillary's are blocked the plate will never get fully cold and the low pressure will be low or even in a vacuum.

If you did not use a vac pump, there can be moisture blocking the coil. No.. can't blow it out. the capillary circuits are very very restrictive.

How a system behaves..

when off.. the pressures are equal in capillary systems. when comp starts, ambient evaporator pressures (high like 17-20) will slowly come down as the tiny compressor starts pulling from the low side. the low pressure and plate temp will come down less then 10. this takes time! Again. every time you to give it a shot.. it has to try all over again.

Air conditioning systems respond fast. The smaller a refrigeration system is, the longer it takes to get down to operating pressures that should not be be constantly checked.
 
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#27 ·
If moisture has been introduced into the circuit, that has to be eliminated before going further. Not sure how to determine, if that was the case, other than the partially frozen evaporator symptom.

Denise would be more helpful, but I believe you need to purge and refill the system with nitrogen and install a special desiccant filter and let it run for hours and hours, maybe even doing it twice. Then the drier tube must also be replaced. I've never done it, but I've needed it done.
 
#28 ·
If moisture has been introduced into the circuit, that has to be eliminated before going further. Not sure how to determine, if that was the case, other than the partially frozen evaporator symptom.

Denise would be more helpful, but I believe you need to purge and refill the system with nitrogen and install a special desiccant filter and let it run for hours and hours, maybe even doing it twice. Then the drier tube must also be replaced. I've never done it, but I've needed it done.
All very hit & miss, without a charging manifold , taking the hose off after pulling a deep vac, air can get back in, if the charging hose is not also the vac hose. I'd not suggest cutting into the unit without everything needed to work tubing, dryers nitrogen. A good vac run 12-24 hrs should be enough.

Most people just wing it! Charge it like a car ac unit lol
 
#30 ·
Actually, I might have been impatient. I managed to 90% of the plate frozen with the thermostat at half. 40 degrees. and I can hold 50 degrees with the thermostat at 1/4, with maybe 1/4' of the plate frozen.
I just had to wait more time. I suspect there might some moisture in it, it might be a bit slow. But, at this point, this is good enough for me :)
 

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#32 ·
Actually, I might have been impatient. I managed to 90% of the plate frozen with the thermostat at half. 40 degrees. and I can hold 50 degrees with the thermostat at 1/4, with maybe 1/4' of the plate frozen.
I just had to wait more time. I suspect there might some moisture in it, it might be a bit slow. But, at this point, this is good enough for me :)[/QUOTE

It will take some time for the entire box to cool down and for your system to work efficiently..load it up with pre cooled or frozen items and see how the it works. I'd suggest a few cases of Hinano..
 
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