I'm working on a Sanyo BC-1206, replacing the evaporator. This thing is the size of an undercounter fridge, and uses a compressor about the size of one of those dorm fridges (compressor is labeled C-QN61L2A as if that will help). Does anyone have a guess for how much oil should be injected to replace the oil lost in the evap? I'm assuming that it's POE, but what viscosity is common in these things? Perhaps the quantity lost is too little to worry about? Comparable Matsushita compressors seem to use about 195cc of oil.

Also, I should probably find an R134a compatible liquid line dryer, but most of these websites insist on a Make/Model lookup, and NONE of them carry Sanyo parts. I think a generic dryer with 1/4 inch ports would work just fine, so I can add the high-side port along side of the cap tube. Any suggestions?

Thanks,
-Steve

Can you pour out the oil in the coil and then measure it? If it's a small amount, don't worry about it. In the event that you have to add some oil, besure to get refrigeration POE oil, not the stuff used in planes. I'm assuming you're replacing the evap coil because of a leak? Look for a data tag on the box; it should tell you the type and quantity of refrigerant the box uses. Go to www.supco.com and look at filter driers. We call them bullet driers because of their shape. Now you need to know some things. First, put on the smallest filter-drier available. Look at how the existing filter-drier is oriented. What I usually see is the FD is at a downward angle from the condensor coil with the cap tube coming out the bottom. Be sure to replicate that. Before you button the system up, blow thru the cap tube backwards. When you do your evacuation/dehydration you want to get down to 500 microns and then do a one hour blank off test. If you don't have a micron guage, buy one or forget the repair. When you go to recharge, put in exactly the amount of refrigerant the nameplate calls for. You'll need a digital scale to weigh in the charge. After you let the box run for 24 hours, you can make miniature adjustments of the charge if needed. On small cap tube systems there is no wiggle room like there is on commercial systems. Every aspect of the repair has to just right or the repair will fail.

Thanks for the reply, very useful information. Yep, punctured evaporator is the reason for repair.

I was curious why you suggested using the "smallest" filter/dryer available, I hadn't heard that one before. It's clear that using a larger FD will affect the specified charge, is that the reason?

I've considered putting part of a can of "oil charge" (2 oz.) as available at the local auto parts store, but the stated viscosity is "100 ISO". If my guess is correct, the total oil charge is about 5 oz., so I could drain some of the existing oil out so the whole can would be used. However, I wouldn't be surprised to find out that 100 is too viscous for small refrigeration use. I've seen a "68" grade oil available, is that the usual usage for these little boxes?

Also, do you adjust the charge in these using superheat? I've read that you want the superheat to be between 10F and 20F, just as the cooling cycle is ending.

Thanks again,
-Steve

Hi Steve:

Smallest drier because, if you go too big, now you've added a receiver which cap tube systems won't function with. If you get a good evacuation/dehydration then what you really want is the filter aspect of the FD rather than the drier aspect. The evac will dry ithe system out.

I really don't think the oil will be an issue unless you get a lot out of the evap. "68" would be he right grade.

Yes, you owuld want to check the superheat after the box has run and is close to cycling off. However, I've had the best results with weighing in the charge and using superheat as a verification check [I use a clamp type temperature probe for accuracy. Charging by superheat is more of a resi a/c split system procedure. When you're done you don't want the SH so low that the suction line sweats much or you'll get a water on the floor complaint.

Thanks for the reply, again. The evap is ordered, and it looks like URI has both the POE and a dryer, looks like I'd go with the Supco SUD109. I've got to see how this evap kit arrives, I'd guess that the aluminum-to-copper connections are already done, and all I have to do is copper-to-copper. I'll probably have a few bends to do, but that isn't too bad. I can sil-phos it together, although Silva-Brite would probably also work, since it's R134a and the pressures aren't that high. I'll use silver-solder on the steel-to-copper joint at the dryer.

It has been completely impossible to get technical service information from Sanyo on this one. It's at least a little frustrating.

Thanks again,
-Steve