1

IMPORTANT SAFETY INSTRUCTIONS

SAVE THESE INSTRUCTIONS
This manual contains important instructions that should be followed during the installation and
maintenance of the Liebert Static Transfer Switch2 Power Distribution Unit (STS2/PDU).
Read this manual thoroughly, paying special attention to the sections that apply to your installation,
before working with the Static Transfer Switch 2 Power Distribution Unit. Retain this manual for use
by installing personnel.
Refer to 1.2.1 - Handling Considerations before attempting to move the unit.
Liebert Corporation neither recommends nor knowingly sells this product for use with life support or
other FDA-designated ��critical” devices.
The Static Transfer Switch 2 Power Distribution Unit is suitable for indoor use only. Protect the unit
from excessive moisture and install the unit in an area free from flammable liquids, gases and corro-
sive substances.
The unit is designed to operate from solidly grounded AC power sources only. Provide input over-cur-
rent protection in accordance with the unit ratings. Wire and ground the unit according to national
and local electrical safety codes. All wiring should be installed by a qualified electrician.
!WARNING
The unit is supplied by more than one power source. The unit contains hazardous voltages if
any of the input sources are on, even when the unit is in bypass. To isolate the unit, turn off
and lock out all input power sources.
Verify that all input power sources are de-energized and locked out before making connections
inside unit.
Lethal voltages exist inside the unit during normal operation. Only qualified service
personnel should perform maintenance on the STS2/PDU.
NOTE
Read the entire manual before installing or operating the system. Adhere to all operating
instructions and warnings on the unit and in this manual.
!WARNING
Under typical operation and with all STS2/PDU doors closed, only normal safety precautions
are necessary. The area around the STS2/PDU should be kept free of puddles of water, excess
moisture and debris.
ONLY qualified service personnel should perform maintenance on the Static Transfer
Switch 2 Power Distribution Unit. When performing maintenance on any part of the
equipment under power, service personnel and test equipment should be located on rubber
mats. The service personnel should wear insulating shoes for isolation from direct contact
with the floor.
One person should never work alone, even if all power is removed from the equipment. A
second person should be standing by to assist and summon help in case an accident should
occur.
!WARNING
The input sources to the STS2/PDU must be grounded-wye sources. Input sources other than
solidly grounded-wye sources may cause damage to the switch.