Lennox Merit CBX25UH Series Installation Instructions Manual page 11

BLOWER RELAY
NOTE — Refer to wiring diagram located on the unit access panel (or figure 13 above) and blower performance (table 2).
S
All air data measured external to unit with 1 inch non-pleated air filter in place.
S
All factory settings are medium speed except the -48 which is set to low speed from the factory.
S
All data given while air handler is operating with a dry DX coil.
Table 2. CBX25UH Blower Performance (3-Speed PSC) - 240V (CFM @ ESP. - in. W. C.)
Air Handler
Blower Speed
Model
Low (Red)
Med (Blue)
18
High (Black)
Low (Red)
Med (Blue)
24
High (Black)
Low (Red)
30 Med (Blue)
High (Black)
Low (Red)
36 Med (Blue)
High (Black)
Low (Red)
42 Med (Blue)
High (Black)
Low (Red)
Med (Blue)
48
High (Black)
Low (Red)
Med (Blue)
60
High (Black)
S
Blower Performance (CFM vs. ESP inches H2O)
S
Cooling speeds should not be reduced below factory setting.
S
Units with electric heat approved at 0.5" maximum and medium blower speed minimum.
CHANGING BLOWER SPEED
5
BLOWER RELAY
HARNESS
BLUE (MED)
2
4-PIN
BLOWER CONNECTOR
Figure 13. Changing Blower Speed
.10" WC .20" WC
510 495
670 650
905 865
630 625
885 875
1130 1100
900 865
1075 1060
1240 1210
1160 1140
1500 1445
1660 1575
1325 1315
1490 1465
1820 1770
1775 1710
1995 1895
2070 1970
1675 1630
1965 1925
2140 2085
Page 11
PLASTIC CAPS
RED (L0)
BLACK (HI)
YELLOW (COM)
.30" WC .40" WC
475
630
820
615
850
1070 1010
830
1030
1170 1135
1115 1085
1385 1300
1495 1405
1300 1275
1440 1395
1690 1600
1645 1565
1800 1685
1850 1719
1580 1520
1875 1800
2000 1895
.50" WC
420 325
595 505
770 705
610 580
820 780
950
780 740
985 940
1085
990
1200
1390
1225
1315
1500
1470
1560
1595
1450
1695
1795
CBX25UH SERIES