When pumping down a refrigeration system it is recommended to leave _______ residual pressure in the system to prevent air being drawn in through minor leaks or compressor shaft seals.
a. 7 to 15 kPa abs
b. 5 to 15 kPa abs
c. 4 to 14 kPa abs
d. 7 to 14 kPa abs
e. 10 to 20 kPa abs
Answer: D