5326602-XIM-B-1019
Johnson Controls Ducted Systems
45
Sequence Of Operation
Cooling Sequence Of Operation
NOTE:
For more in-depth sequence of operation of the Smart
Equipment™ control please refer to LIT-12011950 on
www.upgnet.com under Product Center \ Equipment
Catalog \ Commercial Products \ Zoning Systems and
Controls.
For ZF units, a "Y1" call for the first stage of cooling is passed to
the Unit Control Board (UCB) which then determines whether
the requested operation is available and if so, which
components to energize. With a "Y1" call for first stage cooling
the UCB will determine if a first stage cooling output is valid as
long as all safeties and time-delays allow a C1 output for
cooling. The C1 relay on the UCB will close and send 24 volts
to the M1 relay starting the first stage compressor and also
energizing M4 relay starting the associated condenser fans.
During any call for fan or cooling the FAN output on the UCB
will energize the M3 relay starting the supply fan.
If a Y2 call is present it is passed to the Unit Control Board
(UCB) which then determines whether the requested operation
is available and if so, which components to energize. With a
"Y2" call for first stage cooling the UCB will determine if a
second stage cooling output is valid as long as all safeties and
time-delays allow a C2 output for cooling. The C2 relay on the
UCB will close and send 24v to the M2 relay starting the second
stage compressor. During any call for fan or cooling the FAN
output on the UCB will energize the M3 relay starting the supply
fan.
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.
No Outdoor Air Options
When the thermostat calls for the first stage of cooling, the low-
voltage control circuit from “R” to “Y1” and “G” is completed.
Table 28: Additional Static Resistance ZF120/150 Cabinet (Metric)
M
3
S
Cooling Only
1
1. Add these resistance values to the available static resistance in the respective Blower Performance Tables.
Economizer
2
3
2. Deduct these resistance values from the available external static pressure shown in the respective Blower Perfor-
mance Table.
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 system is less than 62.1 Pa, the unit will deliver less M3S during full economizer operation.
Electric Heat kW
2
18
24
36
54
1.08
19.9
5.0
19.9
22.4
24.8
32.3
1.18
22.4
5.0
22.4
24.8
27.3
34.8
1.27
27.3
7.5
24.8
29.8
32.3
39.7
1.36
29.8
7.5
27.3
32.3
34.8
44.7
1.46
34.8
7.5
32.3
37.3
39.7
49.7
1.55
39.7
7.5
34.8
42.2
44.7
54.6
1.65
44.7
9.9
39.7
47.2
49.7
59.6
1.74
49.7
9.9
44.7
52.2
49.7
64.6
1.83
57.1
9.9
49.7
57.1
59.6
69.5
1.93
62.1
9.9
54.6
62.1
64.6
77.0
1.02
69.5
12.4
59.6
69.5
72.0
84.4
2.12
74.5
12.4
64.6
74.5
77.0
91.9
2.21
82.0
12.4
72.0
82.0
84.4
99.3
2.30
89.4
12.4
77.0
86.9
91.9
106.8
2.40
96.9
14.9
84.4
94.4
99.3
114.2
2.49
104.3
14.9
91.9
101.8
106.8
121.7
2.59
111.8
14.9
99.3
109.3
114.2
131.6
2.68
119.2
14.9
106.8
116.7
121.7
139.1
2.77
129.1
17.4
114.2
124.2
131.6
146.5
2.87
139.1
17.4
121.7
131.6
139.1
154.0
2.96
149.0
17.4
131.6
139.1
146.5
161.4
