Roberts Gorden NEMA 4 Gas Heater User Manual


 
ROBERTS GORDON
®
ULTRAVAC™ CONTROLLER INSTALLATION MANUAL
36
8.3.6 Variable Frequency Drive 25 A or 10 A Fuse
To replace a fuse, turn off input power to the variable
frequency drive assembly at the breaker or
disconnect switch.
Turn off 120 V power to the relay board inside the
ROBERTS GORDON
®
ULTRAVAC™ Controller. Turn
off the 24 V power switch on the relay board.
Inside the VFD assembly, open the fuse holder by
pulling down the lever to expose the fuse. Remove
the old fuse and insert a new fuse. Verify the correct
fuse rating, 25 A for 1 HP 120 V VFD or 2 HP 230 V
VFD, 10 A for the.75 HP 230 V VFD, 1 HP 460 V VFD
and 2 HP 460 V VFD. Close the fuse holder. Return
power to the VFD assembly and verify that the VFD
LCD screen is on. (dashes displayed). Close the
VFD assembly door.
Return 120V power to the relay board. Turn on 24 V
power switch on the relay board. Press the reset but-
ton on the control board and close the doors.