AC Compressor Mounting Question

[Pasha Saleh]

So I traced my leaking refrigerant issue to the compressor after pressurizing the system and hearing a loud hissing in that area. It was not coming from either of the lines going in and out of the compressor but from the front area so assuming a bad front seal.

As the compressor was new I wonder if this could be caused by the fact that it is mounted upside down? It’s a Sanden SD7B10 (Vintage Air). I think that’s the kind they called the “peanut” compressor and the only way I could get it to fit was by hanging it with the lines facing the bottom. It still turns in the correct direction, but I wonder if this could cause an lubrication issue? Anyone successfully running their compressors in this orientation?

 

[Michael]

That’s how I have my compressor mounted, I don’t think it has any bearing on functionality or sealing.

 

[Randy V]

I don’t believe there is a top or bottom to those compressors as they don’t (to my knowledge) have a sump. The oil is mixed in with the refrigerant and is circulated.
It might be that the seal was improperly installed to begin with.

 

[Bill Kearley]

Was your compressor a real Sanden or one of the many Chineeeeez junk nock offs. I deliberately avoided the junk !!

 

[Morten]

Service / Installation manual

 

[Chris Kouba]

View attachment 139860
Service / Installation manual

Yeah but... the only way it fit in my RCR was as Pasha found- ports pointed down. I asked the same question of the collective and found others in the same situation. I would be willing to bet it's a bum compressor or seal. I've wrung mine out and had no issues with it. I am inclined to agree with Randy based on the empirical data from the forum.

I don’t believe there is a top or bottom to those compressors as they don’t (to my knowledge) have a sump. The oil is mixed in with the refrigerant and is circulated.
It might be that the seal was improperly installed to begin with.

 

[Bill Kearley]

The Sandon site states that the compressor must be mounted with the oil fill plug at the top.
( above 9 o'clock and 3 o'clock ) article 6.5 in there manual. click on post #6 info above.

 

[Pasha Saleh]

Was your compressor a real Sanden or one of the many Chineeeeez junk nock offs. I deliberately avoided the junk !!

Bought directly from Vintage Air. Says "Made in Japan"

 

[Morten]

Look at the Southern GT bracket for the AC compressor. I’m sure you can make it fit with pipework to fit an RCR enginebay

 

[Brian Kissel]

Morten, would you happen to have a picture of that bracket please.

Regards Brian

 

[Randy V]

View attachment 139860
Service / Installation manual

That’s quite interesting…. Thanks for this post!
I went on an excursion down the WWW Rabbit Hole and found a good source of information here;

https://www.sanden.com/objects/AC_compressor_guide_USA_20210730.pdf

Starting on page 9 it shows many of the SD prefix compressors having a sump. These are older designs and many of the newer / smaller compressors don’t show any reservoirs in them.. Some even suitable for use at high RPM (8k+)
Good reading !!

 

[Pasha Saleh]

Hi Randy,

What is the implication of the sump/no sump distinction? My compressor came with paperwork saying the “oil filler port” must be placed no further down than horizontal or it would lead to compressor failure yet I can find no such hold on this model. That paper was marked “SD508” but mine is the mini SD7B10. I really don’t want to spend forever trying to shoehorn this thing in somehow so it is not upside down, especially as other members here have reported no issues running the same compressor inverted.

 

[Morten]

So keep it inverted, and if that works its no need to touch it. If it fails after a season or two, swap for a new

 

[Bill Kearley]

Show us a picture of your situation, front and side views with engine installed, You cant be the only RCR with AC !!!

 

[Randy V]

Hi Randy,

What is the implication of the sump/no sump distinction? My compressor came with paperwork saying the “oil filler port” must be placed no further down than horizontal or it would lead to compressor failure yet I can find no such hold on this model. That paper was marked “SD508” but mine is the mini SD7B10. I really don’t want to spend forever trying to shoehorn this thing in somehow so it is not upside down, especially as other members here have reported no issues running the same compressor inverted.

Here’s the service information that covers your compressor -

https://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf

—
Sump vs Crankcase
A sump is typically where a volume of oil would be stored for an oil pump to pick up and circulate.
A crankcase is merely the housing where the compressor’s pistons / crank (if applicable) / Wobble Plate, move within…
I did not find any drawings of your particular compressor that indicated a sump - but then it just may not have been called out.
All of Sanden’s documentation seem to indicate that the fill / drain plug be mounted within the 9 to 3 O’clock range. Frankly, I’ve not seen this before and have always mounted the compressor where it was convenient and out of the way.
Still - if you have the option, I would mount it per Sanden’s documentation.
The oil, in these compressors, travels with the refrigerant through the entire circuit.

 

[Pasha Saleh]

Got it. I'm going to follow Morten's advice and mount it the way it is (all the lines are cut to length, it barely fits this way and no other way I can imagine) and run it that way until it blows up! And hopefully it doesn't!