Wiring Diagrams - Chromalox SDRA-30-43 Installation And Operation Instructions Manual

7. Loosen the set screw on the fan pulley or motor pulley.
Fig. 3 shows the construction of the fan pulley, the motor
pulley is the same construction.
Figure 3
8. Rotate the front half of the pulley clockwise until it bot-
toms, then rotate counter clockwise until the set screw
aligns with the flat in the threaded half of the pulley. The
pulley is now in position for adjustment. See Table 1 for
the number of turns out. Tip: Leave allen wrench in set
screw and use free hand to fold fan blade.

Wiring Diagrams

Attach all Wires on this
Side of Contactor to
Auxillary Terminals
Blk/Red
or Grey
Fan belt tension
adjusting bolts
P4
P5
P6
T1
T2
Motor
T3
T6
T9
T4
T7
T5
T8
Toggle Switch
Motor Relay
Contactor
L1
L2
L3
Blk
Wht
Blk
Transformer
Control Enclosure
Table B
No. of turns from
full closed
Fan Motor
RPM Pulley
1500 3
1600 2-1/2
1650 2
1725 1-1/2
1800 1
1850 1/2
9. Retighten set screw, use of thread locking compound is
recommended.
10. Adjust fan belt tension, see Fig. 2. A 1/2" of belt deflection
is recommended. Tighten lock nuts.
11. Tighten the 3/8" bolts, see Fig. 1
12. Rotate fan blade to make sure the fan belt does not rub.
13. Reinstall top belt cover, grille and lower belt cover. Tip: In-
stalling the grille before installing the lower cover makes
it easier to access the two lower grille bolts.
Inlet
Outlet
Thermostat Thermostat
4
Run these Wires
Through 1" Conduit
6
No. of turns from full
closed
Fan Fan Motor
Pulley RPM Pulley
1-1/2 1950 1-1/2
1-1/2 2000 1-1/2
1-1/2 2100 1-1/2
1-1/2 2200 1-1/2
1-1/2 2300 1
1-1/2
Cutout
1
10
Heater Terminal Box
SDRA 30kW, 480V, 3PH
Fan
Pulley
3
3-1/2
4
4-1/2
4-1/2
12
Front of
Heater