524581-YIM-I-0512
Johnson Controls Unitary Products
49
Operation
Cooling Sequence Of Operation
For the Predator® series of units, the thermostat makes a
circuit between "R" and "Y1" for the first stage of cooling.
The call is passed to the
Unit Control Board (UCB),
which
then determines whether the requested operation is available
and, if so, which components to energize.
For gas heating, the UCB monitors the "W1" call but does not
handle the operation of the gas furnace. An ignition control
board controls the gas heater operation. For electric heat units,
the UCB passes the call to the electric heater. In both cases,
when the "W1" call is sensed, the indoor air blower is energized
following a specified heating delay.
If at any time a call for both heating and cooling are present, the
heating operation will be performed. If operating, the cooling
system is halted as with a completion of a call for cooling.
Heating always takes priority.
Continuous Blower
By setting the room thermostat fan switch to "ON," the supply
air blower will operate continuously.
Intermittent Blower
With the room thermostat fan switch set to "AUTO" and the
system switch set to either the "AUTO" or "HEAT" settings, the
blower is energized whenever a cooling or heating operation is
requested. The blower is energized after any specified delay
associated with the operation.
When energized, the indoor blower has a minimum run time of
30 seconds. Additionally, the indoor blower has a delay of 10
seconds between operations.
Optional VAV Start-up and Control
Table 21: Additional Static Resistance
Size
(Tons)
Model
CFM
Cooling Only
1
1. Add these values to the available static resistance in the respective Blower Performance Tables.
Economizer
2
,
3
2. Deduct these values from the available external static pressure shown in the respective Blower Performance Tables.
3. The pressure drop through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return air duct is
less than 0.25 IWG, the unit will deliver less CFM during full economizer operation.
4” Filter
2
Electric Heat kW
2
9
18
24
36
54
078 (6.5)
090 (7.5)
102 (8.5)
120 (10)
150 (12.5)
ZJ
1900
0.06
0.02
0.12
0.05
0.06
0.07
0.08
0.10
2100
0.07
0.02
0.13
0.06
0.07
0.08
0.09
0.11
2300
0.08
0.04
0.14
0.07
0.08
0.09
0.10
0.13
2500
0.09
0.11
0.16
0.08
0.09
0.10
0.11
0.14
2700
0.11
0.18
0.17
0.09
0.10
0.12
0.13
0.16
2900
0.12
0.25
0.19
0.10
0.11
0.13
0.14
0.18
3100
0.14
0.31
0.20
0.12
0.13
0.15
0.16
0.20
3300
0.16
0.37
0.22
0.13
0.14
0.17
0.18
0.22
3500
0.18
0.43
0.26
0.15
0.16
0.19
0.20
0.24
3700
0.20
0.49
0.27
0.17
0.18
0.21
0.22
0.26
3900
0.23
0.54
0.29
0.19
0.20
0.23
0.24
0.28
4100
0.25
0.58
0.32
0.21
0.22
0.25
0.26
0.31
4300
0.28
0.65
0.35
0.23
0.24
0.28
0.29
0.34
4500
0.30
0.69
0.38
0.25
0.26
0.30
0.31
0.37
4700
0.33
0.74
0.41
0.28
0.29
0.33
0.34
0.40
4900
0.36
0.78
0.44
0.30
0.31
0.35
0.37
0.43
5100
0.39
0.82
0.47
0.33
0.34
0.38
0.40
0.46
5300
0.42
0.86
0.51
0.35
0.37
0.41
0.43
0.49
5500
0.45
0.89
0.55
0.38
0.40
0.44
0.46
0.53
5700
0.48
0.93
0.58
0.41
0.43
0.47
0.49
0.56
5900
0.52
0.96
0.62
0.44
0.46
0.50
0.53
0.59
6100
0.56
0.98
0.67
0.47
0.49
0.53
0.56
0.62
6300
0.60
1.01
0.71
0.50
0.53
0.56
0.59
0.65
If the unit is operated with the optional manual bypass
switch in the LINE (BYPASS) position and there are
VAV boxes present in the duct system, then boxes must
be driven to the full-open position using a customer-
supplied power source to prevent over-pressurizing and
possible damage to the ductwork.
