User manual

Maintenance
Liebert
®
DS
™
148
13.11.2Digital Compressor Unloading Solenoid(s)
Models 028, 035 and 042
When replacing a digital scroll compressor, digital solenoid valve and coil must be replaced.
Compressor and valve kit are shipped separately. Valve kit must be field-brazed to top of compressor
in proper orientation and supported with original factory bracket.
Models 053, 070 and 077
When replacing a digital scroll compressor, digital solenoid coil must be replaced. Compressor and coil
kit are shipped separately.
13.11.3Compressor Replacement Procedure
1. Disconnect power and follow all warnings at front of this manual.
2. Attach suction and discharge gauges to access fittings.
3. Front-seat service valves to isolate the compressor. Reclaim charge from compressor.
4. Remove marked pressure transducer and discharge pressure switch. Disconnect all electrical
connections.
5. Detach service valves from compressor.
6. Remove failed compressor.
7. If required, follow compressor manufacturer’s suggested clean-out procedures.
8. Install replacement compressor and make all connections. Replace gaskets or seals on service
valves. Replace unloading solenoid.
9. Evacuate, charge and operate per 9.3 - Dehydration/Leak Test and Charging Procedures
for R-407C.
10. Semi-hermetic only: see 5.3 - Semi-Hermetic Compressor Spring Isolation System for
compressor spring adjustment.
NOTICE
Risk of improper component reinstallation. Can cause equipment damage.
Identify and mark location of suction pressure transducer and discharge pressure switch.
These devices look similar and they must be reinstalled in their original location.
13.12 Facility Fluid and Piping Maintenance
Facility water and glycol quality remain a requirement throughout the life of the piping system. Fluid
and piping system maintenance schedules must be established and performed. A local fluid
maintenance program must be established that will evaluate fluid chemistry and apply necessary
treatment. A periodic leak inspection of facility and unit fluid piping is recommended. Refer to 9.1.4 -
Requirements of Systems Using Water or Glycol.
13.13 Paradenser—Water-Cooled Condenser
During normal Paradenser operation, deposits will collect on inside wall of condenser tubes. It must
be cleaned periodically to ensure proper operation. Frequency of cleaning must be locally established
because it varies according to Paradenser usage and local fluid quality. See 13.12 - Facility Fluid
and Piping Maintenance.