6
4. Check for proper line voltage at motor power leads BLK
(at L terminal) and YEL (at N terminal).
5. Using a jumper wire from unit control terminals R to G,
engage motor operation. Check for 24-v output at the
defrost board terminal IFO.
6. Check for proper control signal voltages of 22-v to 28-v at
motor signal leads VIO and BRN.
7. Disconnect unit main power. Apply lockout/tag-out proce-
dures.
8. Reconnect motor power and control signal leads at the
motor terminals.
9. Restore unit main power.
10. The motor should start and run. If the motor does not start,
remove the motor assembly. Replace the motor with one
that has the same part number. Do not substitute with an
alternate design motor as the torque/ speed programming
will not be the same as that on an original factory motor.
REPLACING THE X-13 ECM MOTOR
Before removing the ECM belly-band mounting ring from old
motor:
1. Measure the distance from base of the motor shaft to the
edge of the mounting ring.
2. Remove the motor mounting band and transfer it to the
replacement motor.
3. Position the mounting band at the same distance that was
measured in Step 1.
4. Hand-tighten mounting bolt only. Do not tighten securely
at this time.
5. Insert the motor shaft into the fan wheel hub.
6. Securely tighten the three motor mount arms to the support
cushions and torque the arm mounting screws to 60 in. lbs
(6.8 Nm).
7. Center the fan wheel in the fan housing. Tighten the fan
wheel hub setscrew and torque to 120 in. lbs (13.6 Nm).
8. Ensure the motor terminals are located at a position below
the 3 o’clock position. See Fig. 5. Tighten the motor belly-
band bolt and torque to 80 in. lbs (9.0 Nm).
Supply Fan (Belt-Drive)
The belt-drive supply fan system consists of a forward-curved
centrifugal blower wheel on a solid shaft with two concentric
type bearings, one on each side of the blower housing. A fixed-
pitch driven pulley is attached to the fan shaft and an adjust-
able-pitch driver pulley is on the motor. The pulleys are con-
nected using a V-belt. See Fig. 8.
Fig. 8 — Typical Belt Drive Motor Mounting
VARIABLE FREQUENCY DRIVE (VFD)
For units equipped with a VFD factory-installed option
(FIOP), refer to the following supplement:
Variable Frequency
Drive (VFD) Installation, Setup and Troubleshooting
.
BELT
Check the belt condition and tension quarterly. Inspect the belt
for signs of cracking, fraying or glazing along the inside sur-
faces. Check belt tension by using a spring-force tool, such as
Browning’s “Belt Tension Checker” (part number: 1302546 or
equivalent tool); tension should be 6 lbs at a
5
/
8
-in. (1.6 cm) de-
flection when measured at the centerline of the belt span. This
point is at the center of the belt when measuring the distance
between the motor shaft and the blower shaft.
NOTE: Without the spring-tension tool, place a straight edge
across the belt surface at the pulleys, then push down on the belt at
mid-span using one finger until a
1
/
2
-in. (1.3 cm) deflection is
reached. See Fig. 9.
Adjust belt tension by loosening the motor mounting plate
front and rear bolts and sliding the plate toward the fan (to re-
duce tension) or away from fan (to increase tension). Ensure
the blower shaft and the motor shaft are parallel to each other
(pulleys aligned). When finished, tighten all bolts and torque to
65 to 70 in. lb (7.4 to 7.9 Nm).
Fig. 9 — Checking Blower Motor Belt Tension
REPLACING THE BELT
NOTE: Use a belt with same section type or similar size. Do not
substitute a FHP-type belt. When installing the new belt, do not
use a tool (screwdriver or pry-bar) to force the belt over the pulley
flanges; this will stress the belt and cause a reduction in belt life.
Damage to the pulley can also occur if using a tool to force the belt
over the pulley flanges.
Use the following steps to replace the V-belt. See Fig. 8.
1. Loosen the front and rear motor mounting plate bolts.
Table 2 — Motor Test Volts
UNIT VOLTAGE
MOTOR VOLTAGE
MIN-MAX VOLTS
208/230
230
187-253
460
460
414-506
575
460
414-506
BLOWER PULLEY
V--- BELT
MOTOR
PULLEY
MOTOR MOUNTING
PLATE
MOTOR
MOUNTING
BOLTS (4)
BROWNING BELT
TENSION CHECKER
STRAIGHTEDGE
1/2”
(1.3 cm)
BELT
DEFLECTION
Summary of Contents for WeatherMaker 50KCQ A04 Series
Page 34: ...34 Fig 53 RTU Open Overlay for Economizer Wiring ...
Page 35: ...35 Fig 54 VFD Overlay for W2770 Controller Wiring ...
Page 70: ...70 Fig C 50KCQ A04 A05 A06 Control Wiring Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 71: ...71 Fig D 50KCQ A04 A05 A06 Power Wiring Diagram 208 230 1 60 APPENDIX D WIRING DIAGRAMS ...
Page 72: ...72 Fig E 50KCQ A04 A05 A06 Power Wiring Diagram 208 230 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 73: ...73 Fig F 50KCQ A04 A05 A06 Power Wiring Diagram 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 74: ...74 Fig G 50KCQ A04 A05 A06 Power Wiring Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 75: ...75 Fig H 50KCQ Premier Link Control Diagram APPENDIX D WIRING DIAGRAMS ...
Page 76: ...76 Fig I 50KCQ RTU Open Control Diagram APPENDIX D WIRING DIAGRAMS ...
