Vertiv Liebert MC - Page 20

16
Liebert
®
MC - UM - 10019237MAN_ENG - 31.03.2022
Sealing • When leading the cable through the joint, you are recommended to use the sealant for waterproof
disposal.
• If you do not follow the recommended cable sizes and mode to connect the cables, water leakage may
occur at the waterproof joint.
Hot surfaces • The cables cannot contact with hot objects, such as the copper pipe and water pipe without thermal
insulation pipe, lest the insulation layers should be damaged.
Disconnecting
switch and
protection
• A manual electrical disconnect switch should be installed in accordance with local codes.
• Select and install the line side electrical supply wire and over current protection device(s) according
to the specications on the unit nameplate(s), per the instructions in this manual and according to the
applicable national, state, and local code requirements.
8.6.2 Connection to the Power Supply
Specications for MC equipped with EC fans
Use WYE power supply connection NOTICE
The Liebert
®
MC Condenser equipped with EC
Fan Models is designed to operate with Wye-
connected power.
It will not operate properly with Delta connected
power.
The neutral is for illustration purpose only and is not necessary
for the condenser to function properly.
A eld-supplied isolation transformer or other power solutions
will be needed to for proper condenser function.
The electronically commutated motors included in the Liebert
®
MC are suitable for connection to power supplies with a solidly
grounded neutral.
Acceptable Power Supplies - 380V to 460V Nominal Units - 380V wye with solidly grounded neutral and 220V line-
to-ground
- 460V wye with solidly grounded neutral and 277V line-
to-ground
Unacceptable Power Supplies - 380V to 460V Nominal
Units
- Wye with high-resistance (or impedance) ground
- Delta without ground or with oating ground
- Delta with corner ground
- Delta with grounded center tap
Wiring Instructions
1. Route the power supply cable to
the site disconnect switch and
then to the unit.
2. Route the conduit to the
knockout provided in the bottom
right end of the electrical control
enclosure.
3. Connect the earth ground wire
lead to the marked earth ground
connection terminal provided
near the factory-installed
disconnect switch.
4. Connect the three-phase
cable to the factory-installed
disconnect switch.