Page 12
Table 5
Normal Operating Pressures
80
°
F db / 87
°
F wb RETURN AIR
Air Temperature Entering Outdoor Coil (
°
F)
Model
Pressure
65
°
70
°
75
°
80
°
82
°
85
°
90
°
95
°
100
°
105
°
110
°
115
°
10GCS−024
72
75
79
81
82
83
85
87
88
89
91
92
10GCS−030
67
70
73
75
77
78
81
83
84
84
85
85
10GCS−036
Suction
72
75
77
80
81
82
84
86
88
89
91
92
10GCS−042
Suction
72
75
78
82
83
84
86
88
89
90
92
93
10GCS−048
75
79
80
81
83
84
85
86
87
88
89
90
10GCS−060
79
79
80
81
81
82
83
84
85
86
87
88
10GCS−024
171
185
199
213
219
229
244
260
267
275
301
327
10GCS−030
186
192
198
215
221
231
247
263
282
300
312
323
10GCS−036
Liquid
175
191
207
224
230
239
255
271
288
305
320
335
10GCS−042
Liquid
181
197
213
229
235
245
261
277
294
310
328
345
10GCS−048
172
184
197
212
220
235
251
262
279
297
321
335
10GCS−060
192
205
222
236
249
263
277
293
313
331
348
360
12GCS−024
75
77
80
82
83
84
87
88
90
90
91
92
12GCS−030
67
70
73
76
80
78
82
85
86
86
87
88
12GCS−036
Suction
73
75
78
80
82
82
85
87
88
89
91
92
12GCS−042
Suction
77
78
80
81
81
82
84
85
87
88
89
90
12GCS−048
71
74
75
79
81
81
84
88
87
87
88
89
12GCS−060
74
77
80
81
82
84
85
88
96
96
87
88
12GCS−024
149
164
178
193
195
208
222
237
254
271
289
306
12GCS−030
145
161
178
192
195
207
223
238
254
270
288
305
12GCS−036
Liquid
156
172
187
203
207
219
234
260
267
284
303
322
12GCS−042
Liquid
159
175
190
208
209
222
237
253
270
298
306
326
12GCS−048
152
168
185
198
209
215
230
246
254
281
298
316
12GCS−060
155
190
205
211
215
230
244
269
276
293
311
332
Used carefully, this table could serve as a useful service
guide. Data is based on 80
°
F dry bulb / 87
°
F wet bulb return
air. Allow unit operation to stabilize before taking pressure
readings.
Heating System − Sequence of Operation
When thermostat is calling for heat the draft motor is
energized by the 24 volt relay in the blower ignition control
which closes the 240V contact to the draft motor. When the
speed of the draft motor reaches the proper rpm the
pressure switch closes to power the ignition control.
When PSW on blower/ignition control is energized, a
pre−purge time is initiated (30 seconds nominal). When
pre−purge has expired the main gas valve is energized for
direct ignition. The blower/ignition control will energize the
main gas valve and spark electrode/flame sensor for a
period of 10 seconds. The blower/ignition control will spark
for the full 10 seconds regardless of establishing flame and
then look for a signal from the electrode/flame sensor that a
flame has been established. Forty−five (45) seconds
nominal after the initial trial for ignition, the circulating air
blower will start. If the electrode/flame sensor does not
sense that a flame has been established in the 10 second
interval, then the blower/ignition control will open the 24
volt contacts to the main gas valve. The blower/ignition
control is designed to repeat this trial for ignition a total of
three times. If, at the end of the third trial, a flame still has
not been established, then the blower/ignition control will
try to light again one hour later. The one hour retry is
indefinite. The blower/ignition control can be reset by
interrupting the unit power or the thermostat circuit. When
the thermostat is satisfied the draft motor gas valve is
de−energized. The blower motor will continue to run for 120
seconds after the furnace is shut down.
Condenser Fan Clearances
Figure 10 illustrates the critical measurements of the out
door fan system. This dimension should be checked and
fan adjusted accordingly anytime servicing of the outdoor
fan system is required.
Condenser Fan Clearances
Figure 10
A
Unit Model No.
A
−024
−030,−036,−042,−048,−060
3−1/2 in.
3 in.
Downloaded from
