All Sensible Capacity
Air On
Cooling
Coil
Temperature of Air on Condenser
95
°
F
105
°
F
115
°
F
Total
Cap.,
MBH
Power
Input,
KW
Sensible Capacity, MBH
Total
Cap.,
MBH
Power
Input,
KW
Sensible Capacity, MBH
Total
Cap.,
MBH
Power
Input,
KW
Sensible Capacity, MBH
CFM
WB
°
F
Entering Dry Bulb,
°
F
Entering Dry Bulb,
°
F
Entering Dry Bulb,
°
F
86
80
74
68
86
80
74
68
86
80
74
68
H1CE150/K1EU180
6250
72
163
13.7
135
99
63
-
156
15.1
132
96
60
-
149
16.8
129
94
58
-
67
157
13.5
157
130
94
57
151
15.0
151
127
91
55
145
16.7
145
124
89
52
62
157
13.5
157
147
125
89
151
15.0
151
141
122
87
144
16.7
144
135
119
84
57
156
13.5
156
147
137
119
150
15.0
150
141
132
116
144
16.7
144
135
126
113
5000
72
160
13.6
12.
90
60
-
153
15.0
118
88
57
-
145
16.7
115
85
55
-
67
150
13.3
144
117
87
56
144
14.8
141
114
84
53
138
16.5
138
111
81
51
62
149
13.3
149
139
113
83
143
14.8
143
134
110
80
137
16.5
137
129
107
77
57
148
13.3
148
139
131
108
143
14.8
143
134
125
105
137
16.5
137
129
120
102
3750
72
155
13.4
104
81
57
-
148
14.9
102
79
54
-
141
16.6
100
76
52
-
67
143
13.2
125
102
79
54
137
14.6
122
99
76
52
131
16.3
119
97
73
49
62
137
13.0
137
122
99
76
132
14.5
132
119
96
73
127
16.2
127
116
93
70
57
137
13.0
137
129
118
96
132
14.5
132
124
115
93
127
16.2
127
119
111
90
NOTE: These capacities are gross ratings. For net capacities, determine the KW requirement of the supply air blower motor per the published BLOWER PERFORMANCE data. Convert
KW to MBH per the following equation and deduct this equivalent heat from the gross cooling ratings.
The KW input ratings listed above include the compressor and condenser fan motor(s).
UNIT OPERATION - 7-1/2, 10 & 12-1/2 TON
When the external control calls for cooling at terminal Y1:
1. The system controller (SC) is energized. The system con-
troller starts the tandem compressors and enables the
condenser fans by energizing contactor 1M (and 2M on
the 10 and 12-1/2 ton, 208/230 volt models).
The single condenser fan is energized with the compres-
sors on the 7-1/2 ton models.
Condenser fan motor #1 is energized with the compres-
sors on the 10 and 12-1/2 ton models while fan #2 is en-
abled with compressor operation. Fan motor #2 operation
is controlled through the Ambient Temperature Switch
(ATS) which will de-energize the motor when the ambient
temperature falls below 70
°
F.
2. Safety Lockout: The system controller (SC) has a lockout
circuit to prevent compressor short-cycling on a safety
control with automatic reset. If the high or low refrigerant
pressure switches (HP or LP) open, the SC will enter
lockout mode.
SC provides a 90 second bypass of the low pressure switch
LP to prevent nuisance lockouts during unit start-up.
A malfunction light (24V, 2 A max. resistive load) can be en-
ergized through SC, by connecting the light between termi-
nals X and B on TB1.
NOTE: To reset the unit after a lockout:
A. Turn the system switch on the thermostat to the ‘‘OFF’’
position and back to the ‘‘COOL’’ position.
OR
B. Increase the set point of the room thermostat above the
temperature in the conditioned space and returning it to its
original setting.
If the unit continues to be shut down by one of its safety controls,
a service man should be called to determine the cause of the
problem. Repeated resetting of the lockout circuit may damage
the unit.
SYSTEM COOLING CAPACITIES AND POWER REQUIREMENTS
SEQUENCE OF OPERATION
550.23-TG1Y
Unitary Products Group
5
