The total refrigerant charge is calculated using the following equations:
Total refrigerant charge (kg) = Base refrigerant charge (kg) + Refrigerant charge per meter of each size of liquid pipe
(kg/m) × ((Total length of liquid pipe (m) - 10 (m))
Total refrigerant charge (lb) = Base refrigerant charge (lb) + Refrigerant charge per meter of each size of liquid pipe (lb/ft)
× ((Total length of liquid pipe (ft) - 32.8 (ft))
Model
Base Refrigerant Charge without Low Ambient
Kit kg (lb)
Base Refrigerant Charge with Low Ambient Kit
kg (lb)
CRD25
10 (20.9)
25 (55.1)
CRD35
13.5 (29.8)
28.5 (62.8)
Table 7.3 Base Refrigerant Charge
Liquid Pipe Diameter mm(in.)
Refrigerant Charge Per Meter of Liquid Pipe kg/m (lb/ft)
16 (5/8)
0.174 (0.117)
18 (3/4)
0.245 (0.165)
22 (7/8)
0.321 (0.216)
Table 7.4 Refrigerant Charge Per Meter of Each Size of Liquid Pipe
The extra lubricating oil charge is calculated using the following equations:
Extra lubricating oil charge (ml) = Base lubricating oil charge (ml) + Refrigerant charge per meter of each size of liquid
pipe (kg/m) × [ (Total length of liquid pipe (m) - 30 (m) ] × 1000 x 12%
Extra lubricating oil charge (oz) = Base lubricating oil charge (oz) + Refrigerant charge per meter of each size of liquid pipe
(lb/ft) × [ (Total length of liquid pipe (ft) – 98.4 (ft) ] × 1.84
Model
Base Lubricating Oil Charge without Low
Ambient Kit ml (oz)
Base Lubricating Oil Charge with Low Ambient
Kit ml (oz)
CRD25
0
3650 (123.4)
CRD35
0
3650 (123.4)
Table 7.5 Base Lubricating Oil Charge
7.1.2 Evacuating the Unit
NOTE: Before evacuating the unit, switch off the circuit breakers of the compressor, indoor fans, outdoor fans, electric
heater, and humidifier.
To evacuate the unit:
1.
Switch on the circuit breaker of the transformer.
2.
On the HMI display, choose Maintenance > Manual Mode, and select On for Vacuumize Pipeline. EEV and
solenoid valve will be opened.
3.
Manually open all the ball valves.
4. Connect a manifold gauge to the vacuum pump. Connect the manifold gauge to the Schrader valves 3, 11 and
14, as shown in
a. Pull an initial deep vacuum of 65 Pa(a) or 500 microns on the system with a suitable pump.
7 Start-up
51
Vertiv™ Liebert® CRV CRD25 and CRD35 Row-Based Cooling System User Manual
