Step 7 - Adjust Indoor-Fan Speed; Belt-Drive Motors - Carrier 50HJQ004-007 Installation, Start-Up And Service Instructions Manual

Step 7 — Adjust Indoor-Fan Speed —
fan rpm to meet jobsite conditions.
Table 5 shows fan rpm at motor pulley settings for the
50HJQ004-007 units. Tables 6 and 7 shows data for indoor-fan
motors. Refer to Table 8 for accessory and option static pres-
sure drops, see Table 9 for indoor-fan motor efficiency, see
Tables 10-25 to determine fan speed settings.
For units with electric heating, required minimum cfm is
900 for 50HJQ004; 1200 for 50HJQ005; 1500 for 50HJQ006
and 1800 for 50HJQ007.
BELT-DRIVE MOTORS — Fan motor pulleys are factory-
set for speed shown in Table 1. Check pulley alignment and
belt tension prior to start-up.
To change fan speed:
1. Shut off unit power supply and tag disconnect.
2. Loosen belt by loosening fan motor mounting nuts. See
Fig. 33.
3. Loosen movable pulley flange setscrew (see Fig. 34).
4. Screw movable flange toward fixed flange to increase
speed or away from fixed flange to decrease speed.
Increasing fan speed increases load on motor. Do not ex-
ceed maximum speed specified in Table 1.
5. Set movable flange at nearest keyway of pulley hub and
tighten setscrew. (See Table 1 for speed change for each
full turn of pulley flange.)
To align fan and motor pulleys (see Fig. 34):
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from
mounting.
To adjust belt tension:
1. Loosen fan motor mounting nuts.
2. Slide motor mounting plate away from fan scroll for
5
proper belt tension ( /
8
force).
3. Tighten motor mounting nuts.
4. Adjust bolt and tighten nut to secure motor in fixed
position.
UNIT
50HJQ 1
0 /
2
004 1090 1055
004† 1455 1423
005 1185 1150
005† 1455 1423
006 1460 1425
006† 1685 1589
007 1585 1540
007† 1685 1589
*Approximate fan rpm shown.
†Indicates high-static motor and drive package.
Adjust indoor-
-in. deflection with 7 to 10 lbs
Table 5 — Fan Rpm at Motor Pulley Settings*
1
1 1 / 2
2
1025 990 960
1392 1360 1328
1115 1080 1045
1392 1360 1328
1385 1350 1315
1557 1525 1493
1490 1445 1395
1557 1525 1493
Fig. 33 — Belt Drive Motor Mounting
Fig. 34 — Evaporator-Fan Pulley Adjustment
MOTOR PULLEY TURNS OPEN
1 1
2 / 3 3 /
2 2
925 890 860
1297 1265 1233
1015 980 945
1297 1265 1233
1275 1240 1205
1460 1428 1396
1350 1300 1255
1460 1428 1396
19
1
4 4 / 5 5
2
825 795 760
1202 1170 1138 1107
910 875 840
1202 1170 1138 1107
1165 1130 1095 1055
1364 1332 1300
1210 1165 1120
1364 1332 1300
1
/ 6
2
— —
1075
— —
1075
1020
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