Liebert Universal Monitor - Manual (Page 27)

Installation - Optional Expansion Board
19
3.4 Input Power Connections - Optional Expansion Board
The optional Expansion Board requires 24VAC for proper operation. Liebert recommends using the
optional Transformer Module manufactured by Liebert or another UL-approved Class 2 power unit to
obtain proper voltage. If the power unit is not a Class 2 circuit, it must be protected with an IEC
5 x 20mm time lag 2A fuse. For information, consult your local dealer, Liebert representative or the
Liebert Worldwide Support Group.
To connect electrical power:
1. Run 24VAC electrical power from the TB2 (or TB1) connector of the Transformer Module, as
shown in Figure 10, or another 24V source to the Expansion Board in accordance with local
electrical codes.
2. Use copper wires only; proper wiring to use for power is 18-22 AWG stranded and shielded
(18 AWG is recommended—see Table 9). Strip wires 1/2".
Figure 10 Electrical connections to panel
3. Secure the incoming electrical service wires to the Expansion Board’s 24VAC input by sliding the
wires into AC1 and AC2, the 24VAC input connectors, as shown in Figure 10. There is no
polarity requirement when connecting to these connectors.
NOTE: The ground wire connection to the 0V connector is pre-wired at the factory.
!
CAUTION
The Expansion Board is designed for use on properly grounded (earthed) 24VAC Class 2
power, 50Hz or 60Hz. The ground wire for the power lead must be wired to the earth ground
terminal (stud located next to the 24VAC terminal block). This equipment is intended to be
installed by a qualified and certified electrician who must review and approve customer-
supplied wiring and circuit breakers, verify correct input and grounded (earthed) connections
to ensure compliance with technical standards and national and local electrical codes.
!
WARNING
“RISK OF ELECTRIC SHOCK” - More than one disconnect switch may be required to
de-energize the equipment before servicing.
!
WARNING
Hazardous voltage may be present.
S4
EIA485 + (to UM-)
0V
EIA485 - (to UM+)
POWER INPUT
TRANSFORMER MODULE
(TM115 shown)
24VAC output (TB2 shown;
use either TB1 or TB2)
24VAC wiring
(red & white)
24VAC input
connectors
(AC1 & AC2)
Ground wire
(pre-wired)
OPTIONAL EXPANSION BOARD
Ground wire
connector
(0V)