Tech Challenge – January 2019
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A medium temperature cooler utilizing R-134a with a TXV metering device with receiver, has a customer complaint of “warm product.” The symptoms confirm warm product and the condensing unit is cycling frequently on the LPC (low pressure control). With only one problem intended, what are the “possible causes” with the following measured conditions on this field service check sheet?
Field Service Check Sheet
| Compressor Discharge Temp. | 190 deg. F |
| Condensing Press./Temp. | 105 psig / 90 deg. F. |
| Condensing Outlet | 77 deg. F. |
| Condenser Sub cooling | 13 deg. F. |
| Condenser Split | 15 deg. F. |
| Entering Feed Device Temp. | 41 deg. F. |
| Evaporator Press./Temp. | 3 psig / -7 deg. F. |
| Evaporator Outlet Temp. | 37 deg. F. |
| Evaporator Superheat | 30 deg. F. |
| Compressor Inlet Temp. | 68 deg. F. |
| Total S. H. | 61 deg. F. |
| Ambient Temp. | 75 deg. F. |
| Room/Box Temp. | 52 deg. F |
| Compressor Volts | 240 V. |
| Compressor Amp. Draw | Low |
Looking for the Answer: Check hvac-blog.acca.org on February 28, 2019, for the answer to this issue’s Tech Challenge.
Posted In: ACCA Now, Tech Challenge
