Evaporator orientation question AB Cold Machine

[Capt ScubaDave]

I have a used AB Cold Machine, fairly recent since it has a BD35 compressor, but I'm having problems and wondering if the Evap(Freezer) unit orientation might affect it.

I had table tested the whole system before bringing it to the boat this week. With a good battery with a charger on it, as well, I set up the system on the work table complete. First there was a problem because the T'stat used a two-pole flat connector, while the compressor was set for an RJ-11 telephone connector. I modified the Cold Machine connector, since the phone connector was corroded beyond use. I've seen since, I could have just connected direct to terminals C & T on the control module and may do that eventually.

The Evap(Freezer) box I got with the setup has a door on it and fastens to the ice box with standoffs through the large side of the evap unit with the door swinging up. I set the unit flat on the table at the time, and connected as directed to the Cold Machine. Pretty quickly I felt a decided coolness passing through the tubing near the evap unit, but it never got really cold throughout. But, it was 90+ degrees where I was working. Undeterred, I decided to put the box in a cooler chest, to see if it did better. It did! I left it overnight with some ice trays in the box and I got ice. Not complete, but the lid couldn't close all the way, so I told myself "success" and left it at that.

After disassembly, I took the unit to my boat, over 500 miles from home, and started the install. I don't have room for orienting the box flat against the top of the ice box, there wasn't enough depth for the unit to fit under the edge, so it left the door too close to the other side to open. So, instead, I mounted it sideways against the largest wall, as high as I could put it. The ice trays fit on the new 'side' with no problem. The unit is mounted with the required standoffs and the T'stat sensing tube is attached properly with the plastic holding it from direct contact with the evap metal.

Then, I powered it and hoped for cold soda! But, I found I had a wiring issue and had to fix that first. Finally, the compressor started, the fan soon kicked in and it seemed I was going to be really happy - NOT! No joy in the NOT cold evap department. The unit struggled away; I could, at first, feel some cold coming to the tubing near the evap and I could hear fluid running, like the sound of running water.

It went like that through last night until this AM. Then, inexplicably, it stopped completely. Well, I couldn't see the idiot light AB put on the unit below a PCB quick mount as I looked down at it from above; I had to crawl into the locker to get that view. Then, I saw the low battery blink. So, I switched banks and the unit returned to its cycling that drained my first batt bank. It comes on for about a minute, shuts down for 5 secs, then, restarts again for another min before shutting down and going through the process again - and again - and again!

I may have several problems, but I wondered if the orientation of the evap, sideway to its normal orientation would affect it?? I'm going to try to put a picture here to show what I have in place to help with further details for brave souls who may come to my rescue.

Looks like I'll have to find a host for my pics, so I'll end here and post them when able. The evap box is not ID'd as docs I've seen show, but I believe it would be called a LFH-1, but the only label says, "WAECO Adler/Barbour 38906".

I'm at the boat for the rest of the week and I'm hoping someone can help ASAP. But, don't let lateness stop you. It's unlikely my knight in armor will ride in today or even soon, so please try to help no matter when you see this.

Regards,

Capt. ScubaDave
'83 Allmand 31 Hull 31187

Salty Dog 2
Chocowinity, NC (Though I'm with it in New Rochelle, NY until I bring it down south in August - with Reefer working?)

[Frankly]

Even a tiny amount of moisture can bring one of those capillary tube machines to a halt. Should be able to hear the freon expanding into the evaporator plate and should have frost over some part of evaporator.

I worked on one years back and had to run the vacuum pump 7 or 8 hours to get all the moisture out.


Frankly

[Capt ScubaDave]

Frankly,

Thanks! I see that orientation really doesn't matter, but now I'm worried about moisture. What does moisture in it sound like versus R134a running through the Evap? Is there a distinct sound difference. Right now, I have no frost on anything but the tubing leading to the capillary joint (I think that's what it is).

Thanks again,

Capt ScubaDave

[Frankly]

My experience was that the moisture froze and blocked the flow of freon. The capillary tube interior is very small. The dead giveaway was complete silence when you presses your ear to the evaporator.

Turn the unit off for a couple of hours and let the evaporator warm up. Fire it off, you should hear the freon flowing (not loud but audible with your head in the box). Then after a few hours if you can still hear the flow, moisture probably not the issue. If the flow noise has disappeared, might go looking for a vacuum pump and freon.


Frankly

[Capt ScubaDave]

Frankly,

Thanks again! I think that's what I inadvertently did. It drained the batts in the one bank and I didn't realize for a few hours what went wrong. I finally turned it back on after it was cool by switching banks and now it seems to be cooling better than earlier. I can hear the coolant movement in the Evap and it cooled a lot further than before. I have the lid on the box now to see if it can get to the frost point. Hopefully, that will work, once the cycle is established properly. Meanwhile, I'm on to setting up the AutoHelm system, I hope. I'll check on Reefer later and report success or failure.

Thanks

Capt ScubaDave

[Richard Kollmann]

If your AB unit has a BD35 compressor it was built prior to year 1998, With out knowing complete history the refrigerant could be contaminated with solid items or moisture restricting causing off and on ice or even congealed oil.

Standard AB evaporators can be mounted in any position because the refrigerant flow before leaving evaporator passes through liquid control accumulator areas.

Sounds from evaporators only indicate pulsations of flow because compressor is running you are only wasting time with old ideas like this.

Testing for moisture blocking capillary tube is simple because it only blocks refrigerant flow for a short time then melts and freezes again. True indication of moisture in cap tube is this freezing and thawing will keep evaporator temperature at just above freezing producing cold moisture on exterior of plate and no frost cover.

Dirt or other solids restricting cap tube opening are generally permanent. Many cap tube systems have a screen that can fill with deposits only restricting some flow. Sludge thicking or overheated oil restricting flow will sometimes be identified by difficulty in compressor starting.

[Capt ScubaDave]

Richard

Thank you for the sage description of what is happening. I can see/understand what you are indicating to me. It made me think of something else in my installation that I wonder about the effect of: because of the hole to the sail lock in which I have the compressor and its relation to the ice box position I have the Evap paced, I had to have the entire white painted part ot the tubing somewhat wrapped around the Evap comiing from the back, up over the (side)top of the unit and down the other side and then sort of back and up to he hole. A very convoluted path. the coiling of the capillary tubing is all in the ice box chamber and mainly at the lowest point of the route before it heads up too the exit hole from the ice box to the locker. That area that wraps around the tubing is the coldest area first, but eventually goes warm as the unit stops, either from running down the batteries or maybe, from freezing there and stopping the cold from reaching into the Evap any longer? Should I reroute the tubing so it either keeps this section of capillary transition high, or even outside the box more directly - even if this means having some of that white section out of the box?

Or , am I all wet with my speculation? Contorting into the box on this vessel is not easy, to say the least, but its no good to me not working, and I need a solution, not my speculation. Ideas? I'll make my old body do what's needed if you have a solution I need to try.

Regards

Capt. ScubaDave

[Capt ScubaDave]

Hopefully, these pics show my config adequately for spotting any problems. Does the white tubing have to be in or out of the ice box? Does it matter how it runs? Does it need to not touch the Evap except where it attaches?


Thanks

Capt. ScubaDave

[Capt ScubaDave]

If Pics don't show again, they are in 'members galleries' with my name Capt ScubaDave

Just learning how to deal with pics on the Forum.

Capt. ScubaDave

[Capt ScubaDave]

[IMG][/IMG]

[Coolerking]

Where did you get the system from?
Any past history?
You obviously had to reconnect the fittings at ther condenser, did they look ok?
It sounds like you need to first be 100% on the 12vdc feed to it.
Make absolutely sure you have good clean wiring and a solid 12vdc constant at the unit.
Then.
Jumper the C and T terminals for an hour or so while you watch to be sure the compressor runs 100% of the time.
The fan can also fail and cause the compressor to stop.
Report back.

[Richard Kollmann]

If you did not kink the tubing inside box or increase the manufacturers number of capillary tubing sub cooling turns around copper return line the evaporator and tubing looks OK.

Performance depends on correct volume of refrigerant, what method did you use to determine correct volume?

The correct amp draw of that unit is 3 to 6 amps depending on preset compressor speed. After 20 minutes running what is amp draw of unit?

[Coolerking]

I would definitely listen to Richard's suggestions, he has a huge amount of experience with marine refrigeration systems.
Keep us posted.
You have no idea how nice it is to help troubleshoot this stuff without having to perform what I call, "Boat Yoga".
The stories...

[Capt ScubaDave]

Riichard

I didn't modify the tubing, at all, so that first question should be fine. No kinks, so it should be fine.

I have no idea how much coolant i have in the system. I was told it was charged and ready, but have no way to check it right now. Suggestions to approach that need? I've got Auto stores here I could try for a gage set up, but I thought I saw this unit has a different size fill valve (smaller) and I don't know where the other larger valve is located on the unit. The unit does use R-134a Fluid, and I have some on hand, just no way to do anything with it. Also, I saw in other answers on the Forum, that you don't think it's wise to charge it like we do car systems. In fact, you recommend discharging a small amount of fluid to help the system, if I recall correctly.

As for the current draw, I'll have to see if my meter can handle the AMPs since this is a DC system and I can't use a Clip-On Ammeter, right?

I'l try to see what I can do in the AM. Both banks are currently down. Apparently, I knocked the charger switch off as its right behind my back when I'm in the locker working tubing and compressor items.

I'll post tomorrow on progress. It's cooler now, but marina is fussy about noise after dinner hour.

Thank you for getting back to me. I almost went ahead and removed the Evap unit to rerun that tubing.

Regards

Capt ScubaDave

[Capt ScubaDave]

My meter says it has a 10 Amp setting next to the rest of the DCA reading settings. Most in the DCA section are micro and milliamp readings. But, it doesn't say DC near the 10 AMP setting, so I'm just hoping.

Let all know what goes on in the AM.

Thanks again.

Capt ScubaDave