Emerson Liebert OpenComms SL-19534 - Manual (Page 3)

Installation
1
1.0 I
NSTALLATION
The optional Dual Unit Control is designed to control two InteleCool or two InteleCool2® units in a
lead/lag fashion. The control contains an electronic timer for switching the operating sequence of two
units at intervals of one, two, four or eight days.
It also contains a two-stage heat/two-stage cool electronic thermostat with individual heat and cool
setpoints. Light emitting diodes (LEDs) indicate Lead Unit 1 or 2 and power to Unit 1 or Unit 2. If
required for service, thelead/lag unit may be selected manually with the P2 jumper on the Dual Unit
Control board.
1.1 Connecting the Dual Unit Controller to an Electronic Thermostat
The instructions below refer to Liebert’s original InteleCool and newer InteleCool2.
1.1.1 Connecting the Dual Unit Controller to an InteleCool2
1. Install and level the Dual Unit Control. Leveling is not critical because the electronic thermostat
does not contain mercury-filled limit switches.
2. Wire the InteleCool2 Units to the Dual Unit Control using industry standard thermostat cable.
Each IntlelCool2 will need at least 4 conductor, 20 gauge copper, Class 2 wire for distances up to
50 feet (15.2m). Use 18 gauge copper, Class 2 wire for distances between 50 and 75 feet
(15.2 - 22.9m).
3. Wire the Dual Unit Control per the diagram on the inside cover of the Dual Unit Control. The
InteleCool2 to Dual Unit Control low voltage control wiring connections are:
4. Each InteleCool2 MUST have a jumper wire installed between terminals "G" and "Y". This
ensures that the fan will energize on a call for cooling.
For continuous operation of InteleCool2 unit evaporator fans, the “G” and “R” terminals may be
connected. In this mode the jumper between the “G” and “Y” terminals should be removed, and
the lead/lag function will control only the condenser fans, compressors, and heaters.
5. Tighten and check all connections for correct installation.
6. Refer to the thermostat user manual for setup and operation of the electronic thermostat.
InteleCool2 Terminals Dual Unit Control Terminals
R - 24 VAC R
1 - 24 VAC RTN 1/2
W - Heating W
G - Evaporator Fan See Step 4 below
Y - Cooling Y