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PBG-9
B. BLOWER MOTOR INSTALLATION
1. Secure and support new motor (G) mounting face against the blower housing (I), with
the motor shaft inserted through the shaft opening into the blower housing. Refer to
Figure 4 for component identification.
2. Insert and tighten the four 3/8-16 UNC bolts (H) that fasten the motor to the blower
housing, tighten to 20 ft-lbs.
3. Insert the impeller (D) onto the motor shaft, the open side of the impeller faces away
from the motor (penetrating oil or lubricant may be required). Note the motor shaft is
keyed, and the key must be aligned with the corresponding key opening on the impeller
hub. Note that care must be taken not to damage the impeller or the motor bearings
during this process. Damaging the impeller or motor bearings will cause an imbalance
that will result in excessive vibration when the impeller is rotating which can damage
motor bearings and other coupled equipment.
4. Align the end of the motor shaft flush with the face of the impeller hub. Tighten the two
¼-20 set screws (F) on the impeller hub into the motor shaft, tighten to 55 in-lbs.
5. Spin the impeller by hand to confirm unimpaired rotation. The impeller and motor
should spin freely with no contact with the blower housing or any fastener within.
6. Place the blower face plate gasket (E) onto the face plate (C), align the holes in the face
plate and gasket with the corresponding holes in the blower housing face plate mounting
flange. Insert and tighten the eight sheet metal screws (B). Care should be taken to
keep the gasket properly aligned and flat for a proper seal.
7. Open the motor wiring terminal box (A); reconnect the electrical power supply wires to
the appropriate motor leads. Close the motor wiring terminal box.
8. Verify the burner is off and reconnect the electrical power supply.
9. Momentarily energize the blower motor and verify proper rotational direction. Direction
of rotation should correspond with the directional arrows (J) on the blower housing.
10. Verify blower and burner balance and vibration. Blower and burner assemblies are trim
balanced to 0.26 in/sec. or less at motor speed (3600 rpm). Failure to trim balance
and/or correct an imbalance will result in excessive vibration when the impeller is
rotating which can damage motor bearings and other coupled equipment.
IMPORTANT
When replacing the blower motor, it is important to note that the PBGII 300-1000 size burners are
designed for and should be equipped with either:
- Single Phase Motor = 1/3HP-T-3600RPM, 110-220V/1ph/60Hz, frame-56C , or
- Three Phase Motor = 1/3HP-T-3600RPM, 230-460V/3ph/60Hz, frame-56C
Replacement motor must meet these specifications to insure proper functionality of the system.
WARNING
Local and national codes and standards should be strictly adhered to. Voltage, phase
and frequency must be compatible with the motor and electrical accessory nameplate
ratings. All maintenance, repair and wiring to the burner blower, air control motor, and
control accessories must be completed by qualified personnel.