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shills33
26-06-2009, 09:31 PM
I was wondering if someone could help , what is the best way to check my super heat on a diary cabinet? were would be the best places to put my temp probes T1 and T2 to check to c if the superheat is ok on the system and would around 6 C be ok for the difference in the 2 probes for superheat with R 404a. Cheers

jdunc2301
26-06-2009, 09:40 PM
Gauges: attach to suction, note the Saturation temperature.

Temp probe: ideally attach 'tightly' to suction as close to the TEV phial as poss, note the temperature.

Difference between saturation temp and actual pipe
temp is your superheat, ideally 6C

You could attach your temp probe further away from TEV phial if its more convenient but the results won't be as accurate.

Eeram
27-06-2009, 05:37 PM
Allow the system to operate for 20 - 30 minutes to stabilize. Connect gauges that is accurate to suction side of system. Read pressure and convert to temperature, reading a PT chart. Connect a good thermometer to the suction line near the sensing bulb of the TXV valve. Record the suction line temperature.

Subtract the saturated temperature from the actual suction line temperature. Result is the operating superheat.

Example: Suction line temp. = 55F
Suction pressure = 68.5 psig
68.5 psig = 40F
55 - 40F = 15 F Superheat.

Hope this helps

nike123
27-06-2009, 05:51 PM
That depend on what superheat you want to measure.



If you want to measure evaporator superheat, best place is around TXV phial, if it is TXV metering device and at around 20-30 cm after evaporator if it is capillary/orifice metering device.
If you want to measure total superheat, best is around 20-30 cm before compressor.
If you want to measure discharge superheat than best is 20-30 cm after compressor.

Peter_1
28-06-2009, 08:08 AM
I was wondering if someone could help , what is the best way to check my super heat on a diary cabinet? were would be the best places to put my temp probes T1 and T2 to check to c if the superheat is ok on the system and would around 6 C be ok for the difference in the 2 probes for superheat with R 404a. Cheers

T1 firmly attached on the 1st bend of your evaporator (=evaporating temperature) and T2 at the outlet of the evaporator T2-T1 = SH

taz24
29-06-2009, 01:24 AM
T1 firmly attached on the 1st bend of your evaporator (=evaporating temperature) and T2 at the outlet of the evaporator T2-T1 = SH


I agree Peter.

To check superheat you need to use gauges as other have posted but Shills33 asked how it was done with a thermomiter and you gave him a better answer than I could have done :)

Cheers taz.

.

shills33
21-07-2009, 01:06 PM
cheers for the help