Liebert DS User Manual

This manual contains important safety instructions that should be followed during the installation 

and maintenance of the Liebert DS

™

. Read this manual thoroughly before attempting to install or 

operate this unit.
Only qualified personnel should move, install or service this equipment. 
Adhere to all warnings, cautions and installation, operating and safety instructions on the unit and in 

this manual. Follow all operating and user instructions.

Risk of electric shock. Can cause injury or death.
Disconnect local and remote power supplies before working within.
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 iCOM microprocessor does not isolate power from the unit, even in the “unit off” mode. 

Some internal components require and receive power even during the “unit off” mode of iCOM 

control.
The factory-supplied optional disconnect switch is inside the unit. The line side of this switch 

contains live high-voltage.
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.

Risk of explosive discharge from high-pressure refrigerant. Can cause injury or death.
This unit contains fluids and gases under high pressure. Relieve pressure before working with 

piping.

Risk of refrigerant system rupture or explosion from overpressurization. Can cause 

equipment damage, injury or death.
If a pressure relief device is not provided with the condenser unit, the system installer must 

provide and install a discharge pressure relief valve rated for a maximum of 500 psig (34bar) 

in the high side refrigerant circuit. Do not install a shutoff valve between the compressor and 

the field installed relief valve.
One or more additional pressure relief valves are required downstream of any and all field-

installed isolation valves as shown in Figures 57 and 58. Do not isolate any refrigerant 

circuits from overpressurization protection.
For systems requiring EU CE compliance (50Hz), the pressure relief valve must be CE 

certified to the EU Pressure Equipment Directive by an EU “Notified Body.”

NOTE
A pressure relief valve is provided with Liebert Lee-Temp