TROUBLESHOOTING
Figure 13
Status Lights
Status 1
• Flashing: Input Current limit has been reached. Even if speed dial is turned to
increase speed, the speed is locked and will not rise.
Status 2
• Flashing: Motor Overload fault is pending. Motor current has exceeded maximum
allowed current (5.5A-RF2 & 7.5A-RF4) and Redi-Flo VFD will trip on an overload
(OL1) fault in 60 seconds if speed is not turned down (load reduced).
Status 3
• Flashing: Undercurrent fault is pending. If the speed is not turned down within 8
seconds, the Redi-Flo VFD will trip on an under current (UC) fault.
• Solid: Under current trip/fault is disabled.
Redi-Flo Variable Frequency Drive
The Redi-Flo VFD will display an fault if any major fault occurs.
If the display
shows this:
The
Fault is:
Remedy:
Which may be
caused by:
Over temperature • The VFD is overloaded • Reduce the load by reducing the frequency
• The VFD is thermally
• Check that the VFD's max. amb. temp. is
overloaded
not exceeded and it has proper ventilation
• Defective VFD
• Have VFD checked by Grundfos
technician
Under voltage
• Input voltage too low
• Reset the VFD, if it cuts out again, check
• Input wire run too long
voltage at VFD and power source to
• Input wire size too
determine where voltage loss has occurred
small
and increase voltage as needed
• DC bus is charging
• Check input 120,230 voltage wiring
termination
• Check input voltage
Over voltage
• Input voltage too high
• Reset the VFD, if it cuts out again check
voltage at power source and reduce
voltage as needed
Motor overload
• Motor drawing
• Check pump for blockage or excess wear,
high amps
repair or replace as needed
(5.5A-RF2/7.5A-RF4)
• Check F08 operators adjustments on pg.13
• Locked rotor
• Defective motor
VFD overload
• The VFD is overloaded • Reduce the load by reducing the frequency
• Defective VFD
• Have VFD checked by Grundfos technician
Ground fault
• Motor is grounded
• Check motor and lead with megohmmeter
• Cable is damaged
and repair or replace as needed. The
• Transistor shorted
insulation resistance must be greater than
1.5 M *
• Have VFD checked by Grundfos technician
VFD disabled
• Remote connection
• Check external device operation
contact open
• Check Jumper
• Jumper between
terminals 1-10
removed
Over current
• Motor or motor lead
• Reduce the frequency
defective/damaged
• Check motor and lead with megohmmeter
• VFD amp draw above
and repair or replace as needed. The
16A
insulation resistance must be greater than
• Defective motor
1.5 M
*
• Defective VFD
• Check pump for locked rotor condition
• Have VFD checked by Grundfos technician
Under current
• Pump running dry or
• Check water level, drawdown,
shut off or at pump off
pumping level and above ground pressure
for these conditions
• Check pump for proper rotation
• Motor current below
• Let motor cool and try to restart
UC (F10)setting
Restart delay
• Under current restart is • Pump will automatically restart after preset
pending
delay
• Set "0" on F11 to eliminate auto
restart
No Motor Load
• Motor is not connected • Check ambient fluid temperature
• Motor thermal is open
• Reduce motor load
• Connect motor to drive
Page 18
TROUBLESHOOTING
Page 17
*Do not use megohmmeter at Redi-Flo VFD output terminals.
The Redi-Flo VFD can indicate the presence of a pending fault by the use of status lights
on the digital readout display see Figure 13 below.
TR'sVFDIO.p65
5/31/00, 9:02 AM
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