Heat Controller DMC09SB-0 - Page 49

Service Manual 49
Troubleshooting Guide
Additional gas charging
(Gas leakage)
• When refrigerant is insufficient by leakage, recharge the unit with the refrigerant up to normal oper-
ating suction pressure.
• Use the graph or the equation below to get operating suction pressure according to indoor and out-
door temperature.
Suction pressure was measured at 3-way valve service port after operating the unit for 10 minutes.
The method of using graph
- Find outdoor temperature.
- Find indoor temperature onto the curve of outdoor temperature.
- Read suction pressure at the axis of ordinates.
The method of using equation
-. Calculate suction pressure after putting indoor and outdoor temperature into the equation.
184.9
(At operating the Unit for 10 minutes)
Suction Pressure
(PSI)
Outdoor Temp.
(˚F)
Indoor Temp. (˚F)
170.7
156.5
142.2
128
113.8
99.5
85
71.1
41 50 59 68 77 86 95 104
122˚F
104˚F
86˚F
68˚F
50˚F
0˚F
Operating Suction Pressure (For R410A)
(According to Indoor & Outdoor Temperature)