5052617-UIM-E-1116
34
Johnson Controls Unitary Products
NOTES:
1. Airflow expressed in standard cubic feet per minute (SCFM).
2. Motor voltage at 115 V.
SECTION X: SAFETY CONTROLS
CONTROL CIRCUIT FUSE
A 3-amp fuse is provided on the control circuit board to protect the 24-
volt transformer from overload caused by control circuit wiring errors.
This is an ATO 3, automotive type fuse and is located on the control
board.
BLOWER DOOR SAFETY SWITCH
This unit is equipped with an electrical interlock switch mounted in the
burner compartment. This switch interrupts all power at the unit when
the panel covering the blower compartment is removed.
Electrical supply to this unit is dependent upon the panel that covers the
blower compartment being in place and properly positioned.
ROLLOUT SWITCH CONTROLS
These controls are mounted on the burner assembly. If the temperature
in the area surrounding burner exceeds its set point, the gas valve is
de-energized. The operation of this control indicates a malfunction in
the combustion air blower, heat exchanger or a blocked vent pipe con-
nection. Corrective action is required. These are manual reset controls
that must be reset before operation can continue.
PRESSURE SWITCHES
This furnace is supplied with three pressure switches, which monitor the
flow through the combustion air/vent piping and condensate drain sys-
tem. These switches de-energize the gas valve if any of the following
conditions are present. Refer to "CONDENSATE PIPING AND FUR-
NACE VENTING CONFIGURATION" for tubing connections.
1.
Blockage of combustion air piping or terminals.
2.
Blockage of condensate drain piping.
3.
Blockage of vent piping or terminal.
4.
Failure of combustion air blower motor.
Table 19:
Blower Performance CFM - Any Position (without filter)
Models
Speed
Bottom Airflow Data
(SCFM)
Ext. Static Pressure (in. H
2
O)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
40A
High 1290
1260
1220
1160
1100
1040
960
840
750
660
Medium High
1170
1140
1110
1070
1040
990
930
820
730
650
Medium
990
980
940
900
860
830
790
730
680
630
Medium Low
900
880
850
810
770
730
670
630
600
560
Low 730
710
690
650
620
590
540
510
480
450
60B
High 1402
1374
1354
1328
1299
1262
1222
1167
1107
1036
Medium High
1252
1233
1203
1182
1150
1125
1095
1064
1031
980
Medium
1076
1059
1029
1007
973
946
908
883
843
800
Medium Low
988
967
936
903
875
838
806
765
737
685
Low 798
769
727
695
650
619
574
517
485
443
80B
High 1445
1423
1397
1365
1339
1311
1283
1250
1204
1140
Medium High
1282
1266
1232
1211
1182
1157
1128
1097
1069
1013
Medium
1098
1084
1059
1027
998
967
939
910
879
822
Medium Low
1012
993
953
930
894
851
828
773
752
692
Low 865
810
763
730
689
628
594
520
496
448
80C
High 1713
1682
1643
1600
1558
1519
1480
1436
1385
1333
Medium High
1554
1519
1485
1439
1404
1368
1327
1280
1176
1130
Medium
1380
1351
1302
1263
1224
1171
1128
1085
1030
943
Medium Low
1177
1142
1083
1050
988
922
890
819
798
687
Low 951
841
650
588
457
418
355
227
203
N / A
100C
High 1734
1694
1650
1611
1570
1536
1485
1438
1392
1335
Medium High
1568
1537
1492
1453
1414
1373
1327
1279
1230
1118
Medium
1420
1380
1332
1294
1249
1196
1152
1100
981
938
Medium 1218
1169
1124
1067
1015
965
894
845
754
679
Low 979
846
647
580
464
427
345
220
195
N / A
100C
High 2143
2102
2065
2028
1989
1944
1892
1825
1733
1625
Medium High
1788
1749
1718
1672
1629
1587
1541
1500
1447
1355
Medium
1575
1539
1500
1456
1410
1363
1305
1246
1095
1030
Medium Low
1372
1325
1276
1225
1170
1111
1044
972
884
812
Low 1031
921
810
728
660
615
518
474
391
355
120D
High 2214
2173
2132
2086
2036
1994
1952
1907
1849
1777
Medium High
1841
1799
1749
1699
1659
1611
1567
1520
1471
1372
Medium
1605
1562
1514
1470
1416
1361
1310
1180
1119
1045
Medium Low
1405
1362
1303
1244
1189
1125
1054
986
876
826
Low 1135
1020
844
758
671
557
511
464
387
N / A
Main power to the unit must still be interrupted at the main power dis-
connect switch before any service or repair work is to be done to the
unit. Do not rely upon the interlock switch as a main power discon-
nect.
Blower and burner must never be operated without the blower panel
in place.
