Maintenance & Troubleshooting
Vertiv | Liebert CRD10 | User Manual
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Chapter 7: Maintenance & Troubleshooting
This chapter deals with the system operation and maintenance of the Liebert CRD10 range of air
conditioners. In this chapter, the following points or items will be discussed to help users get to grips with
the routine inspections and checks from a end-user-perspective. It includes the maintenance of electrical
parts and connections, refrigerant system maintenance guidelines, routine monthly and semi-annual
checklists, and drainage system maintenance among others. It also discusses the basic troubleshooting
which can be understood from a user perspective.
WARNING! Arc flash and electric shock hazard. Open all local and remote electric power-supply
disconnect switches, verify with a voltmeter that power is Off and wear appropriate, OSHA-approved
personal protective equipment (PPE) per NFPA 70E before working within the electric control
enclosure. Failure to comply can cause serious injury or death. Customer must provide earth ground
to unit, per NEC, CEC and local codes, as applicable. Before proceeding with installation, read all
instructions, verify that all the parts are included and check the nameplate to be sure the voltage
matches available utility power. The Liebert® controller does not isolate power from the unit, even in
the “Unit Off” mode. Some
internal components require and receive power ev
en during the “Unit Off”
mode of the controller. The only way to ensure that there is NO voltage inside the unit is to install and
open a remote disconnect switch. Refer to unit electrical schematic. Follow all local codes.
WARNING! Risk of contact with high-speed rotating fan blades. Can cause serious injury or death.
Open all local and remote electric power-supply disconnect switches, verify with a voltmeter that
power is off, and verify that all fan blades have stopped rotating before working in the unit cabinet or
on the fan assembly. If control voltage is applied, the fan motor can restart without warning after a
power failure.
WARNING! Risk of contact with extremely hot and/or cold surfaces. Can cause injury. Verify that all
components have reached a temperature that is safe for human contact or wear appropriate, OSHA-
approved PPE before working within the electric connection enclosures or unit cabinet. Perform
maintenance only when the system is de-energized and component temperatures have become safe
for human contact.
WARNING! Risk of hair, clothing and jewelry entanglement with high speed rotating fan blades. Can
cause equipment damage, serious injury or death. Keep hair, jewelry and loose clothing secured and
away from rotating fan blades during unit operation.
CAUTION: Risk of excessive refrigerant line pressure. Can cause tubing and component rupture
resulting in equipment damage and personal injury. Do not close off the refrigerant-line isolation
valve for repairs unless a pressure-relief valve is field- installed in the line between the isolation valve
and the check valve. The pressure-relief valve must be rated 5% to 10% higher than the system-design
pressure. An increase in ambient temperature can cause the pressure of the isolated refrigerant to
rise and exceed the system-design pressure rating (marked on the unit nameplate).
