5.Subtract the outdoor ambient temperature from the liquid line temperture to determine the approach temperature.
° Liquid Line Temperature °F
_
° Outdoor Ambient Temperature °F
=° Approach Temperature °F
6.Compare the approach value with those shown in Table
8.If the values do not agree with those provided in Table 8, add refrigerant to lower the approach temperature or recover refrigerant from the system to increase the approach temperature.
Approach Values for TXV Systems
Approach value is the liquid line temperature minus the outdoor ambient temperature (±1°F).
Note: For best results, use the same digital thermometer to check both outdoor ambient and liquid temperatures.
Table 8
Check Charge Using Normal Operating Pressures
Use Table 7 to perform maintenance checks. Table 7 is not a procedure for charging the system. Minor variations in these pressures may be due to differences in installations. Significant deviations could mean that the system is not properly charged or that a problem exists with some component in the system.
Issue 1004 | Page 16 |
