Emerson Liebert OpenComms SL-19534 - Manual (Page 5)

Control Startup
3
2.0 C
ONTROL
S
TARTUP
2.1 Start the Dual Unit Control
1. Turn the thermostat Off.
2. Turn on power to both InteleCool2 units.
3. Turn on circuit breakers in each InteleCool2. Both green “POWER ON” LED’s and 1 of the green
“LEAD UNIT” LED’s of the Dual Unit Control will be lit if the unit has been properly connected.
4. Turn the thermostat switch to the “Auto” setting.
One or both of the InteleCool2 units should start if the thermostat is in a call for heating or cool-
ing.
2.2 Check for Operation
1. Raise the thermostat setpoint to force a call for heating.
2. Then lower the thermostat setpoint to force a call for cooling.
The InteleCool2 unit’s fans should run when there is a call for either heating or cooling.
2.3 Lead Unit Schedule & Selection
After verifying the connections and startup, the lead unit may be selected and the lead/lag schedule
may be set.
2.3.1 Designating the Lead InteleCool2 Unit
The position of the P4 jumper on the Dual Unit Control board determines which InteleCool2 unit is
the lead unit: the P4 jumper will be on pins 3 and 4, or “NORMAL.”
Designation as the lead unit may be determined externally by checking a unit’s LEAD UNIT LEDs on
the front panel of the DUC . The InteleCool2 unit whose LEAD UNIT LED is lit is the lead unit. If the
designation is satisfactory, no changes are necessary.
To change which InteleCool2 unit is the lead unit, place the P4 jumper on pins 1 and 2 or “REVERSE”
on the Dual Unit Control in the InteleCool2 unit chosen to serve as the lead unit.
2.3.2 Schedule
The Dual Unit Control lead/lag schedule may be set with jumpers on the printed circuit board. By
using the P2 and P3 jumpers and Table 1, the jumpers may be placed for the desired number of days
between switchover. The P2 jumper is on the lower right hand corner of the board (see Figure 1). The
P3 jumper is on the lower mid section of the board (see Figure 1).
Table 1
Switch/jumper settings
# Days for Lead/ Lag
Switchover Cycle P2 P3
8 Pins 8/4DAY Pins 1 & 2 (SLOW)
4 Pins 4/2DAY Pins 1 & 2 (SLOW)
2 Pins 4/2DAY Pins 3 & 4 (FAST)
1 Pins 2/1 DAY Pins 3 & 4 (FAST)
NOTE
If the lead/lag schedule is changed while the unit is running, the schedule change may not
take effect until the original schedule is completed. Also, the unit will retain the lead/lag order
of the units, even if power is removed, for two to five days, depending on the setting of the P2
and P3 jumpers.