User manual

SEC-HD user manual Appendix B: Troubleshooting
53
Variable fan not running
Incorrect wiring
 Correct the wiring. For more information, read
Connecting variable-stage cooling elements
on page 15.
The fuse is open or blown.
 Check why the fuse was blown and repair any
problems. Replace the fuse.
The variable stage is configured as
OFF
 Configure the variable stage for cooling. For
more information, read Configuring the
stages on page 23.
The idle speed setting is too low.
 Increase the idle speed setting. For more
information, read Programming variable
stages on page 30.
The idle range temperature setting
is too high.
 Decrease the idle range temperature
setting. For more information, read
Programming variable stages on page 30.
The temperature set point is
above room temperature.
 Adjust the set point to the desired
temperature. For more information, read
Programming variable stages on page 30.
There is no power to the fan.
 Switch on the power.
Faulty fan/heater
 Replace the equipment.
Circuit breaker open
 Reset the breaker.
Variable speed fan responds to
only a small portion of the 0 to
100% range
Incorrect motor curve
 Configure the stage to use the other motor
curve. For more information, read
Configuring the stages on page 23.
Variable speed fan comes on,
runs at full speed, and then
turns off, keeps cycling.
The hysteresis is not high enough.
The outside temperature is rising
and falling quickly. This happens
most often in the spring and fall.
 Adjust the hysteresis setting.
Relay does not switch ON the
load
Incorrect wiring
 Correct the wiring.
The stage is configured as OFF, as
cool for a heater, or as heat for a
fan.
 Configure the relay properly. For more
information, read Configuring relay stages,
parameters 21 to 23 on page 24.
The set point is incorrect
 Adjust the setting. For more information, read
the appropriate programming section.
No power to the load
 Switch on the power.
Faulty equipment
 Replace the equipment.
Circuit breaker open
 Reset the breaker.
Blown relay
 Solve the problem that caused the relay to
blow, and then replace the relay or circuit
board.
Relay does not switch OFF the
load
The stage is configured as ON.
 Configure the relay properly. For more
information, read Configuring relay stages,
parameters on page 24.
Alarm relay not operating
alarm system
Incorrect wiring
 Correct the wiring. For more information, read
Connecting an alarm system on page 17.
Staged element cycles on and
off
The set points are too close
together with variable speed fans.
 Adjust the hysteresis setting.
 Move the probe closer to the heater.
 Widen the set points.
The heater is too large for the room.
 Replace the heater with a smaller output unit.
The stage is set up as proportional
control.
 Change the configuration from proportional
control.