September 2015 Tech Challenge
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A rooftop[ utilizing R-410A with a TXV feed device has a customer complaint of insufficient cooling. The symptoms confirm inadequate cooling, and the compressor appears to be short cycling. What are the “possible causes” (not there is only one problem intended) with the following measured conditions on this field service check sheet?
Field Service Check Sheet
| Compressor Discharge Temp. | 240 deg. F. |
| Condensing Press./Temp. | 444 psig / 125 deg. F. |
| Condensing Outlet Temp. | 90 deg. F. |
| Condenser Sub cooling | 35 deg. F. |
| Condenser Split | 37 deg. F. |
| Entering Feed Device Temp. | 89 deg. F. |
| Evaporator Press./Temp. | 157 psig / 55 deg. F. |
| Evaporator Outlet Temp. | 68 deg. F. |
| Evaporator Superheat | 13 deg. F. |
| Compressor Inlet Temp. | 73 deg. F. |
| Total S. H. | 18 Deg. F. |
| Ambient Temp. | 88 deg. F. |
| Room/Box Temp. | 78 deg. F |
| Compressor Volts | 240 V. |
| Compressor Amp. Draw | High |
Looking for the answer? Check back on October 30, 2015.
Posted In: ACCA Now, Tech Challenge
