NOTICE
Risk of improper power supply connection. Can cause equipment damage and loss of warranty coverage.
Prior to connecting any equipment to a main or alternate power source (for example: backup generator
systems) for startup, commissioning, testing, or normal operation, ensure that these sources are correctly
adjusted to the nameplate voltage and frequency of all equipment to be connected. In general, power source
voltages should be stabilized and regulated to within ±10% of the load nameplate nominal voltage. Also, ensure
that no three phase sources are single phased at any time.
See transformer label for primary tap connections. Installer will need to change transformer primary taps if
applied unit voltage is other than pre-wired tap voltage.
NOTE: Seal openings around piping and electrical connection to prevent air leakage. Failure to do so could reduce the
unit’s cooling performance.
Three phase electrical service is required for all models. Electrical service must conform to national and local electrical
codes. Refer to equipment nameplate regarding wire size and circuit protection requirements. Refer the appropriate
submittal drawing, listed in Table 5.1 below, for electrical service entrances into unit
•
Liebert® DSE voltage should be verified with available power supply before installation. Refer to the unit’s
electrical schematic and serial tag for specific electrical requirements. Line voltage electrical service is also
required for all condensers at the location of the condenser.
•
For the most reliable operation of the system, the indoor unit and the Liebert® MCV condenser should be on the
same power source. The Liebert® DSE system offers an option for a power feed from the active source on the
indoor unit to the outdoor condenser. This configuration provides the greatest reliability and fastest recovery
during power loss or source change.
•
When powering the outdoor condenser from the indoor unit, there is a breaker/fuse on the indoor unit.
•
A unit disconnect is standard on the Liebert® MCV skid. However, a site disconnect may be required per local
code to isolate the unit for maintenance. Refer to the unit’s serial tag for specific condenser electrical
requirements.
•
Route the supply power to the site disconnect switch and then to a factory provided high voltage enclosure
located on the MCV heat rejection skid.
•
A manual electrical disconnect switch should be installed in accordance with local codes and distribution
system. Consult local codes for external disconnect requirements.
The electrical and unit to unit connections are described in the submittal documents included in the Submittal Drawings.
The following table lists the relevant documents by number and title.
Document Number
Title
DPN004797
Liebert® DSE Electrical Field Connections DA250, DA265 Downflow Models
DPN003886
Liebert® Heat Rejection Skid CANbus and Interlock Connections Liebert® MCV and Liebert® MCV
EconoPhase and Base Assembly
Unit to Unit Networking
DPN004351
Liebert® iCOM™ Unit to Unit Network Connections (Liebert® CW, Liebert® CWA, Liebert® DS, Liebert® DSE,
Liebert® PDX, Liebert® PCW
Table 5.1 Electrical Field Connection Drawings
Vertiv | Liebert® DSE Thermal Management System Installer/User Guide
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