ENVIRO-TEC
32
FORM ET115.24-NOM4 (819)
SECTION 2 - START-UP
EC MOTOR TROUBLESHOOTING
GUIDELINES
Ensure motors and blowers are clean as part of normal
maintenance. No further maintenance is required for
these motors.
Follow standard lock out tag out (LOTO)
procedures when performing service on
motor or blower.
TABLE 2 -
EC MOTOR TROUBLESHOOTING GUIDELINES
PROBLEM
POSSIBLE CAUSE
CORRECTIVE ACTION
Motor fails to start
No or loose enable jumper (constant
RPM motor only)
Verify enable jumper connected properly
to motor driver. Refer to
Constant RPM
EC Motor Driver Enable Jumper on page
37
.
No power to motor. Possible blown
fuse or open circuit breaker
Verify line voltage at motor driver. Replace
fuse or reset circuit breaker.
PWM configuration switch in program
mode
Configuration switch 1 must be in Run
mode (
Figure 13 on page 26
). Refer
also to
PWM Board Status LED on page
25
.
PWM board faulted
Refer to
PWM Board Status LED on page
25
. Verify voltage input, wiring and
connections. Push reset button. Replace
PWM board if fault returns.
No control signal (constant RPM)
Constant RPM EC motors will not rotate if
they lose PWM signal while enabled.
Verify PWM signal at motor connector
by connecting a multimeter set for “duty
cycle” between pins 1P1 and 1C (or
between pins 2P1 and 2C). The duty cycle
represents the on-time percentage signal
sent to the motor (this number will vary
between the minimum and maximum duty
cycle set by the factory). See
Figure 12 on
page 25
for PWM board connections.
Refer also to
PWM Board Status LED on
page 25
to verify board is in normal
operating mode.
Improper wiring connections
Verify wiring. If Fan Coil Relay board
present, verify all jumpers installed. Refer
to Fan Coil Relay Board Troubleshooting
Guide.
EC motor wiring harness improperly
seated
Unplug harness and re-install, making
sure plugs are fully seated.
EC motor wiring harness(es) open or
intermittent
Replace harness(es). See section on
Checking EC Wire Harnesses on page
35
.
Blower jammed
Clear blockage. Verify blower rotates
freely with motor disconnected.
No 24 VAC power
Refer to Fan Coil Relay Board
Troubleshooting Guide.
Float switch tripped
Verify float switch (if present) is made.
Motor seized
Verify motor rotates freely by hand with
blower disconnected. If not, replace
motor.
Damaged motor cable
Cable is integral to motor, replace motor.
Summary of Contents for VHA
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Page 41: ...ENVIRO TEC 41 SECTION 2 START UP FORM ET115 24 NOM4 819 THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 54: ...ENVIRO TEC 54 FORM ET115 24 NOM4 819 SECTION 6 Dimensional Data 74 80083 ...
Page 78: ...ENVIRO TEC 78 FORM ET115 24 NOM4 819 SECTION 6 Dimensional Data NOTES ...