5
Fig. 7 — ECM Unit Wiring
ECM MOTOR
The direct-drive motor is an X13 Electronically Commutated
Motor (ECM). An ECM motor contains electronic circuitry
used to convert single-phase line AC voltage into 3-phase DC
voltage to power the motor circuit. The motor circuit is a DC
brushless design with a permanent magnet rotor. On the X13
ECM motor design, the electronic circuitry is integral to the
motor assembly and cannot be serviced or replaced separately.
208/230-v units use a 230-v motor, 460-v units use a 460-v
motor and 575-v units use a 460-v motor with an autotrans-
former. Motor power voltage is connected to motor terminals L
and N (see Fig. 6 and Fig. 7); ground is connected at terminal
G. The motor power voltage is ALWAYS present; it is not
switched off by a motor contactor.
Motor operation is initiated by the presence of a 24-v control
signal to one of the five motor communications terminals.
When the 24-v signal is removed, the motor will stop. The mo-
tor control signal is switched by the defrost board’s IFO output.
Evaluating motor speed
The X13 ECM Motor uses a constant torque motor design. The
motor speed is adjusted by the motor control circuitry to main-
tain the programmed shaft torque. Consequently there is no
specific speed value assigned to each control tap setting. At the
Position 5 tap, the motor speed is approximately 1050 RPM
(17.5 r/s), but varies depending on fan wheel loading.
Selecting speed tap
The five communication terminals are each programmed to pro-
vide a different motor torque output. See Table 1. Factory default
tap selection is Position 1 for lowest torque/speed operation.
Factory Default: Tap 1 (VIO).
Selecting another speed:
1. Disconnect main power to the unit. Apply lockout/tag-out
procedures.
2. Remove the default motor signal lead (VIO) from terminal
1 at the motor communications terminal.
3. Reconnect the motor signal lead to the desired speed (ter-
minals 1 through 5).
4. Connect main power to the unit.
Motor “rocking” on start-up
When the motor first starts, the rotor (and attached wheel) will
“rock” back and forth as the motor tests for rotational direction.
Once the correct rotational direction is determined by the motor
circuitry, the motor will ramp up to the specified speed. The
“rocking” is a normal operating characteristic of ECM motors.
Troubleshooting the ECM motor
Troubleshooting the X13 ECM requires a voltmeter.
1. Disconnect main power to the unit.
2. Remove the motor power plug (including the control BRN
lead) and VIO control signal lead at the motor terminals.
3. Restore main unit power.
575-v Units
208/230, 460-v Units
Table 1 — 50KCQ Motor Tap Programming (percent
of full-load torque)
UNIT SIZE
TAP 1
TAP 2
TAP 3
TAP 4
TAP 5
04
29
33
41
48
100
05
46
49
57
67
100
06
49
55
79
90
100
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 ...
