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ROBERTS GORDON
®
ULTRAVAC™ CONTROLLER INSTALLATION MANUAL
38
Troubleshooting Flow Chart (continued)
Replace rotary disconnect
base block.
Is there power (120 V or
230 V) between the rotary
disconnect outputs?
Turn rotary disconnect
switch to the ON position.
See Section 6.1.
Check circuit breaker and
power supply.
Motor bearings may have
failed. Repace motor.
No
Is the pump impeller
obstructed?
No
Disconnect power to the
motor. Does the motor
shaft turn freely?
Motor may have tripped
overload. Wait 10-15
minutes and reset.
No
Yes
Is the pump motor hot?
Rectify wiring between
VFD and pump.
Yes
No
Is there power between any
two input wires at the
pump?
Replace VFD. See
Replacement Parts
section.
Yes
No
Is there 120 V (230 V for
460 V models) between any
two output (motor) terminals
(U,V or W)?
Refer to the VFD
manufacturer's Installation
and Operation Manual to
clear error.
Replace VFD. See
Replacement Parts
section.
Rectify wiring between fuse
holder outputs and VFD
power inputs L1 and L2/N
Replace fuse. See
Replacement Parts
section.
Is there power (120 V or
230 V) between the rotary
disconnect inputs?
No
No
No
Yes
Yes
Yes
Is there power (120 V or
230 V) between fuse
holder inputs?
No
Yes
Is there power (120 V or
230 V) between fuse
holder outputs?
No
Yes
Is there power (120 V or
230 V) between L1 and
L2/N inputs on the VFD?
No
Yes
Is the LCD display
of the VFD on?
Rectify wiring between
120 V relay and VFD
terminals 1 and 11.
No
Yes
Is there continuity between
VFD terminals 1 and 11?
No
Yes
Is there an error showing
on the LED display?
Replace 120 V relay.
See Replacement Parts
section.
No
Yes
Is there continuity between
output terminals on 120 V
relay.
Rectify wiring between
controller and 120 V relay.
No
Yes
Is there 120 V into 120 V
relay in the variable
frequency drive assembly.
Replace plug-in relay or
relay board. See
Replacement Parts section.
No
Yes
Is there 120 V at output # 8
on the relay board?
Replace plug-in relay.
See Replacement Parts
section.
Secure wiring between 24 V
Output #8 on control board
and 24 V input connection
#8 on relay board.
Yes
No
Is there 24 Vac across 24 V
input connection #8 on the
relay board?
No
Verify external wiring
diagrams, Does the pump
turn on?
Yes
No
Is the red LED on plug-in
relay #8 on the relay board
lit?
Yes
Yes
Yes
Yes
Yes