Electrical Connections
57
Liebert
®
CRV
™
9.0
E
LECTRICAL
C
ONNECTIONS
9.1
Electrical Field Connections Descriptions
9.1.1 Standard Electrical Connections—600mm (24") models
(Source: DPN001884, Rev. 5, Page 1)
1.
High Voltage Connection Through the Bottom of the Electric Panel
—1-3/8" (34.9mm),
1-3/4" (44.5mm) 2-1/2" (64mm) diameter concentric knockout.
2.
Low Voltage Connection Through the Bottom of the Electric Panel
—Quantity (2) 7/8"
(22mm) diameter knockouts.
3.
High Voltage Connection Through the Top of the Unit
—1-3/8" (34.9mm), 1-3/4" (44.5mm)
and 2-1/2" (64mm) diameter concentric knockout.
4.
Low Voltage Connection Through the Top of the Unit
—Quantity (4) 7/8" (22mm) diameter
knockouts.
5.
Three-Phase Electrical Service
—Connect to terminals on disconnect switch. Three-phase
service not by Liebert (see
NOTICE on page 58
).
6. Factory-Installed locking Disconnect Switch
7.
Earth Ground
—Terminal for field-supplied earth grounding wire.
8.
Remote Unit Shutdown
—Replace existing jumper between Terminals 37 and 38 with
field-supplied normally closed switch having a minimum 75VA, 24VAC rating. Use field-supplied
Class 1 wiring.
9.
Customer Alarm Inputs
—Terminals for field supplied, normally closed contacts, having a
minimum 75VA, 24VAC rating, between Terminals 3 and 50, 2 and 51, 5 and 55 or between 3 and
56. Use Class 1, field-supplied wiring. Terminals 3 and 56 are used for humidifier alarm when a
humidifier is installed. The remaining terminals are available for customer alarm inputs, such as
smoke sensors and building fire alarms.
10.
Common Alarm
—On any alarm, normally open dry contact is closed across Terminals 75 and 76
for remote indication. 1A, 24VAC maximum load. Use field-supplied Class 1 wiring.
11.
Heat Rejection Interlock
—On any call for compressor operation, normally open dry contact is
closed across Terminals 70 and 71 to heat rejection equipment. 1A, 24VAC maximum load. Use
field-supplied Class 1 wiring.
12.
CANbus Connector
—Terminal block with terminals 49-1 (CAN-H) and 49-3 (CAN-L) + SH
(shield connection). The terminals are used to connect the CANbus communication cable
(provided by others) from the indoor unit to the Liebert MC (Premium Model).
The CANbus cable, provided by others and used to connect to the outdoor condenser, must have
the following specifications:
a. Conductors—22-18AWG stranded tinned copper
b. Twisted pair (minimum eight twists per foot [305mm])
c. Braided shield or foil shield with drain wire
d. Low Capacitance—15pf/ft or less
e. UL approved temperature rated to 167°F (75°C)
f. UL approved voltage rated to 300V
g. UV- and moisture-resistant if not provided in conduit.
h. Plenum rated—NEC type CMP (if required by national or local codes.)