BD35 compressor not making frost on plate .

[ColdEH]

Thats Good , I was enjoying the analogy.

Thanks Rich , Got the crimp off and the tubes are open. just two holes . Tell me more .

Ponies are ready to go .

Regards

[Richard Kollmann]

No a64 pilot you have not got it. After refrigerant charge is confirmed to be low or too much by nondestructive means it can be adjusted by frost covered areas…..
Bad advice is one way for a boater with a problem to be doomed as you say….
Knowing the correct volume of refrigerant by weight is not easy to find on many manufactured icebox conversion units, so pressure amperage and frost cover are all that is available in mobile refrigeration applications…..
When a Thermally controlled Expansion Valve is used to maintain correct super heat a receiver tank to store excess refrigerant is required when valve reduces refrigerant flow to achieve lower evaporator temperatures…..
The accumulator you refer to is normally built into the evaporator’s design for these small units to collects liquid oil and refrigerants remaining as a solid. By slowly metering liquids held in accumulator back to compressor liquid slugging damage to compressor is averted.

[ColdEH]

Ok so this is what I have so far

32 X11 evaporator plate , 24 feet of passages on it .

Bd35 danfoss compressor ,

Danfoss TN2 , txv with 00 orifice .

Parker 886p1309 receiver drier with sight glass.

Pacific sea breeze condenser, 3r8h.

May work ? Fun project

Did I miss any thing ?

Regards


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[ColdEH]

First change , going with the 0X orifice .
More research .

Regards


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[ramblinrod]

Originally Posted by Richard Kollmann

If the gurgling sound never stops during an extended run and suction pressure stays near 7.5 psi indicates refrigerant contaminated or refrigerant is some what restricted. Lowering static pressure to less than 300 micron for a duration of four hours while keeping system warmed to near 100 degrees F is necessary on systems lubricated with POE oils. This process will remove all vapor gas and dehydrate moisture from system.

Whenever an evaporator is replaced it must be vacuumed clear of test gases Many evaporators are shipped with nitrogen inside as it is not legal to ship them with refrigerant inside. Your system report matches a $2000 experience one other boater had with what was believed to be nitrogen mixed with refrigerant after installing new evaporator.

If this system's oil was contaminated with other additives or unapproved oils you may as well replace complete system.

Nova Kool Ships pre-charged equipment all the time.

[Richard Kollmann]

Rod, It appears Typhoon has decided his problem is refrigerant flow control and not contaminated refrigerant or contaminated oil without actual test confirmation.

[a64pilot]

I think he's playing, and having a good time, if he gets it working then he can sit back with not a little pride when he is enjoying a cold one at the anchorage, knowing he knocked it together himself.
If it doesn't, well he learned something. Homebuilding can be fun, and educational.

[ColdEH]

Originally Posted by a64pilot

I think he's playing, and having a good time, if he gets it working then he can sit back with not a little pride when he is enjoying a cold one at the anchorage, knowing he knocked it together himself.
If it doesn't, well he learned something. Homebuilding can be fun, and educational.

Thanks Pilot, you are right I enjoy the learning process , I didn't build my boat but you can be sure I want to understand and be able to fix just about anything that goes wrong with it

Richard , I did confirm a blockage in the capillary tube , after i got it off I blew compressed air through it backward with a fine strainer tapped on the end . There was a small piece of black rubber in there, looks like it may have come from the resealable connectors . That would have caused my lack of frost on the evaporator.

Just waiting for new parts now , the orifice has proven to be a challenge , the smallest one I could get is ten times the BTU rating that the BD35 is capable of ,

The learning continues

Thanks to this forum and it's members

Regards

[ColdEH]

Just a thought , with the increase in refrigerant , should I be thinking of enlarging the condenser ? Seems like it would be a good idea in the warmer climates , more surface area would be good .

Regards


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[ColdEH]

Originally Posted by typhoon

First change , going with the 0X orifice .
More research .

Regards


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Still fiddling with this thing , keeping my mind busy for sure !

I found an even smaller TXV /TEV , a Honeywell TLK with the smallest orifice of .3 . The TN2 danfoss was a .68 Kw valve with the OX orifice , the Honeywell TLK is .36 Kw . I think this will make it easer to balance the system . It is also available as a MOP valve .

Cant wait to put the pieces together and see if it will work

Regards

[ColdEH]

Just an update .

Got the system all soldered up last week and was very excited to evacuate and charge it up . I was happy to see a good vacuum down to around 450 microns . I heated the entire system in the spray both to 140 degrees to make sure of no moisture . Charged it very slowly , all went well.
Okey here comes the bad part , no laughing ! I wasn't getting any flow at all through the the TXV . I thought I had a blockage ? But I was very careful with my assembly. Oh no ! I had the TXV on backward. !!! LOL . No wonder . Daaaa! O well this is my first condensing unit. So I will evac and unsolder, turn it around and fill it up again , what fun . 😳



Regards


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[SV THIRD DAY]

looks great..
How much refrigerant did you put in as your initial charge starting point?

[ColdEH]

Hey Rich

Initial charge 20oz , then I noticed the pressure rising . Turned off the compressor and the pressure still stayed high . At room temperature the TXV should be wide open , if anything , I should have trouble making that high pressure . The I realized my mistake .
I have two sight glasses in the system, one on the receiver drier and a really big one just before the TXV . Never saw any flow in either one of them . LOL , it's solder time .

What fun . What am I going to do when I get all these things done ?

Regards


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[SV THIRD DAY]

20oz sounds like a good starting point.
Our standard charge is 24oz and based on your photos, I bet your final number will be close to that.

great project!

[ColdEH]

Finally got it working . I evacuated the system and turned around the TXV .
Could not balance the system , this valve has no superheat adjustment but it was designed for small systems so I thought impulse give it a go , no luck . It was to big , just flooded the system and did not make enough of a pressure drop to to get going , I even put the bulb in ice, but still no luck . Evac the system again and put on the Danfoss tn2 with the OX orifice . Finally. ! Got it working . Had to adjust the superheat a bit , but it did the job . Pressures are just under 100 psi high side and 5 psi on the low side , and the plate is out of the box and in the open air , drawing just 2.4 amps at 2000rpm . I'm sure I will have to make a few adjustments when I get it in the box . I am getting loads of sub cooling with this condenser and a slow running 10 inch fan . I'm very happy with the setup , now to build another one for the freezer .

Regards


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