Carrier PC211 specifications Calculate Minimum Load

Calculate Minimum Load

To calculate minimum load conditions, estimate the temperature difference that the cooler will have at 10% load, then estimate what the suction and condensing temperatures will be at this point. Use the proper saturated pressure and temperature for the particular refrigerant used.

Suction Temperature:

43 F (6.1 C) = 73 psig (503 kPa) saturated refrigerant pressure (HCFC-22) Condensing Temperature:

70 F (21.1 C) = 121 psig (834 kPa) saturated refrigerant pressure (HCFC-22) Minimum Load ΔT1:

45.5– 44 = 1.5° F (7.5 – 6.7 = 0.8° C) Minimum Load ΔP1:

121 – 73 = 45 psid (834 – 503 = 331 kPad)

Again, to avoid unnecessary surge prevention, add 10 psid (70 kPad) at ΔP1 from these conditions:

ΔT1 = 1.5 F (0.8 C)

ΔP1 = 60 psid (410 kPad)