IGC/SHI HC-8E compressor shuts down due to 200° F thermal switch opening. Water temp and flow are good to compressor. Suspect water & oil heat exchanger have scale on water side, reducing efficiency. Has anyone used a chemical cleaner to dissolve & clean scale ? Some have suggested to reverse water flow thru unit. Any thoughts or suggestions ?
It is always worth the try --we commonly have to do it to the old Infinion RESCON power supply unit in the bottom of the gradient cabinets and with good success.
That being said -- you have nothing to lose -- try it and see if you get improvement -- otherwise it is not the cooling flow and is truly the unit working too hard and overheating due to some other portion failing -- when was last absorber changed? and is HE gas charged to proepr level -- sometimes MORE is NOT better in the case of HE gas pressure.
Hey Bill, good success with what ? Reverse flow or chemical flush ? The absorber is at least 2 years old but the cold head is working great. Magnet log show no change in over a year. Gas pressure is right in the window.
There are several reasons for a compressor to run too hot, including high compression ratio, high return gas temperatures, and lack of external cooling. the water line on an HC8 is very basic. it wraps around the outside of the compressor. I don't think even your He gas pressure would make a difference other than what it would do to your cold head efficiency. you should check your He gas pressures none the less including the static pressure. On the HC8 you should be around 260-300mB if i recall. watch the gauge and see if it twitches back and forth..
The thermal switch you speak of (I don't have prints anymore) is that the one on the copper water line? if so I think that is on the H20 input side if I remember correctly.
I would really doubt that you have a clogged water line unless you have Arizona water and even CLR would fix that calcium!. If you think so... put a flow gauge on the output side of the H20 Line. That thermal switch can be faulty and they are cheap. Look for air in your water lines. How soon does the unit shout off? approx. 30 sec.?? if it has been over heating you most likely have blown oil into the absorber and it may need to have some oil added.. If it does shut off at 30 sec. put a 2x4 under the left side and see if it runs then. I would want to see the actual flow/temp. The temp requirements are different based on the flow rate of the water. heck you can feel the input and output and they should feel very different. Also when any HVAC type compressor
The switch shutting it down is the one on top of the capsule, under the plastic cover. The top of the compressor module reads about 195F using an IR thermometer. It shuts off maybe once or twice a day for about 10 minutes each time. Not enough to effect boil off yet, but it will only get worse if not addressed. I don't think the water line is actually clogged. I think there may be enough of a deposit layer to reduce the thermal transfer efficiency.
Jim Foros
HC-8E compressor overheats
April 12, 2018 04:36
IGC/SHI HC-8E compressor shuts down due to 200° F thermal switch opening. Water temp and flow are good to compressor. Suspect water & oil heat exchanger have scale on water side, reducing efficiency. Has anyone used a chemical cleaner to dissolve & clean scale ? Some have suggested to reverse water flow thru unit. Any thoughts or suggestions ?
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William Dixon
re: HC-8E compressor overheats
April 13, 2018 09:55
It is always worth the try --we commonly have to do it to the old Infinion RESCON power supply unit in the bottom of the gradient cabinets and with good success.
That being said -- you have nothing to lose -- try it and see if you get improvement -- otherwise it is not the cooling flow and is truly the unit working too hard and overheating due to some other portion failing -- when was last absorber changed? and is HE gas charged to proepr level -- sometimes MORE is NOT better in the case of HE gas pressure.
to rate and post a comment
Jim Foros
re: re: HC-8E compressor overheats
April 13, 2018 05:23
Hey Bill, good success with what ? Reverse flow or chemical flush ? The absorber is at least 2 years old but the cold head is working great. Magnet log show no change in over a year. Gas pressure is right in the window.
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Milner A. Flecha
re: HC-8E compressor overheats
April 13, 2018 10:03
What model of MRI?
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Jim Foros
re: re: HC-8E compressor overheats
April 13, 2018 05:23
Philips Achieva, 2011 DOM
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Milner A. Flecha
re: re: re: HC-8E compressor overheats
April 17, 2018 09:41
Maybe you have to add oil to the compressor.
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Snoclimber
re: re: HC-8E compressor overheats
April 13, 2018 05:23
There are several reasons for a compressor to run too hot, including high compression ratio, high return gas temperatures, and lack of external cooling. the water line on an HC8 is very basic. it wraps around the outside of the compressor. I don't think even your He gas pressure would make a difference other than what it would do to your cold head efficiency. you should check your He gas pressures none the less including the static pressure. On the HC8 you should be around 260-300mB if i recall. watch the gauge and see if it twitches back and forth..
The thermal switch you speak of (I don't have prints anymore) is that the one on the copper water line? if so I think that is on the H20 input side if I remember correctly.
I would really doubt that you have a clogged water line unless you have Arizona water and even CLR would fix that calcium!. If you think so... put a flow gauge on the output side of the H20 Line. That thermal switch can be faulty and they are cheap. Look for air in your water lines. How soon does the unit shout off? approx. 30 sec.?? if it has been over heating you most likely have blown oil into the absorber and it may need to have some oil added.. If it does shut off at 30 sec. put a 2x4 under the left side and see if it runs then. I would want to see the actual flow/temp. The temp requirements are different based on the flow rate of the water. heck you can feel the input and output and they should feel very different. Also when any HVAC type compressor
to rate and post a comment
Jim Foros
re: re: re: HC-8E compressor overheats
April 17, 2018 09:42
The switch shutting it down is the one on top of the capsule, under the plastic cover. The top of the compressor module reads about 195F using an IR thermometer. It shuts off maybe once or twice a day for about 10 minutes each time. Not enough to effect boil off yet, but it will only get worse if not addressed. I don't think the water line is actually clogged. I think there may be enough of a deposit layer to reduce the thermal transfer efficiency.
to rate and post a comment