CVS-21HA.rev.03
35
PROBLEM
CHECK POINTS
The wiring is incorrect.
Correct the wiring. In particular, be sure two
different lines are connected to each fan
motor: line L1 modulated by the controller
should be combined with another line (N for
115V or L2 for 230V) to activate the fan
motor. Also be sure the stage 1
and 2 COMMON is supplied by line L1.
The stage 1 or 2
fans are not
running.
The stage's fuse is open.
Replace the fuse.
The display board interconnect cable is not
plugged into the power supply board properly.
Be sure the cable is firmly plugged in.
The stage 1 or 2 minimum speed is too low.
Adjust the minimum speed to a higher value.
The fan motor is defective.
Connect the fan motor to an alternate
power supply. Repair the motor if it still is
not operating.
The wiring is incorrect.
Correct the wiring.
The stage 1
fans run
continuously at
full speed.
The room temperature is above the set point.
Adjust the set point to the desired value.
The selected motor curve is inappropriate for the
type of fan motors you are using.
Select an appropriate motor curve.
The stage 1 fans
run erratically.
The stage 1 bandwidth is too low.
Adjust the bandwidth to a higher value.
The stage 1 time on or time off is too short.
Adjust the time on or time off to a higher value.