PDA

View Full Version : Semi Hermetic Compressor Maintainance



jbomba
07-05-2009, 11:24 AM
Hi there i have struck a wierd question in my studys about semi hermetic compressor maintainance the question asks the checks manufacturers recomend on doing after a certain ammount of hours of use.

Question: Briefly describe the inspections that are required at the following time periods

1. After 5000 hours or 1 year

2.after 10 000 hours

3. After 20 000 hours

i mainly deal with aircon so dont really strip down and rebuild compressors at all. Be great to get some insight from you guys. ive posted this in technical aswell but i think this would be the correct forum for this question

thanks in advance

D.D.KORANNE
07-05-2009, 11:43 AM
For semi-hermetic compressors
a)connecting rod bearing clearance
b) center & main bearings
c) valve reed leak back check
d) oil pump gear clearance check
e) winding resistance;compare with original values
f) piston rings clearance
these are some of the important checks would give you a clue about the components . For efficiancy loss valve reed leak back is of imortance.

jbomba
07-05-2009, 12:12 PM
For semi-hermetic compressors
a)connecting rod bearing clearance
b) center & main bearings
c) valve reed leak back check
d) oil pump gear clearance check
e) winding resistance;compare with original values
f) piston rings clearance
these are some of the important checks would give you a clue about the components . For efficiancy loss valve reed leak back is of imortance.

thanks for your help any idea which hour category these would each go under?

jbomba
10-05-2009, 10:30 AM
can anybody place these in the timeline for me?

taz24
10-05-2009, 11:12 PM
Hi there i have struck a wierd question in my studys about semi hermetic compressor maintainance the question asks the checks manufacturers recomend on doing after a certain ammount of hours of use.

Question: Briefly describe the inspections that are required at the following time periods

1. After 5000 hours or 1 year

2.after 10 000 hours

3. After 20 000 hours

i mainly deal with aircon so dont really strip down and rebuild compressors at all. Be great to get some insight from you guys. ive posted this in technical aswell but i think this would be the correct forum for this question

thanks in advance


I don't know about NZ but Semi hermetics in the UK are alowed to run into the ground. They are relatively small compressors compaired to open drives.
They don't tend to be much bigger than 50 HP and are designed to run reletively maintanence free.

Twice a year the electrics can be checked for overheating or damage and the compressor run amps can be taken and compared to the data plate or commisioning documents.
The condenser needs to be cleaned and oil pressure tested.
Once a year the oil is dropeded and the oil filter is cleaned, then new oil added.
You can do a valve pump test yearly also.
Leak checks done twice yearly.
But apart from that if it aint broke don't fix it.
Semi hermetics by nature are designed to run with little maintenance.
You would not be expected to test big end or little end bearings.
You must remember that gaskets get damaged when you remove access plates and cylinder heads.
So apart from the oil or if they develop a fault then they are left to do their own thing.


Cheers

taz.

.

Magoo
11-05-2009, 02:30 AM
I agree with Taz, oil changes annually, top end checks annually, electrics etc.., condenser cleans. Filter driers once a year.
Any semi over tens years if fails replace, cheaper than re-build.
Fizz and replace, system balance and performance checks are critical every quarter will dictate compressor reliability. Do not forget evaporator condition and efficiency performance, if gone out of whack can destroy compressors.
magoo