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EC motors have built in protective features that include the following:
•
Over-Temperature protection of the (motor) electronics,
•
Over-Temperature protection of the motor,
•
Locked rotor protection,
•
Phase failure protection,
•
Under voltage detection,
•
Short circuit protection.
If any of the conditions exist, the motor stops electronically and an alarm (FAN FAILURE) will
be indicated on the unit’s controller screen.
The motor will not start-up automatically. To reset, the power supply must be switched to OFF
for a minimum of twenty (20) seconds.
If for any reason the rotor is blocked, the motor will electronically switch off. Before looking for
blockage make certain to remove power from the unit. Once the blockage is cleared the motor
will automatically restart when powered ON.
If there is an alarm condition indicated as “NO AIRFLOW”, all active functions (cooling, heating
and humidification will stop until the alarm is cleared.
EC motors have an under-voltage protection. If the power supply voltage falls below 150
VAC/3Ø (for 230-volt motors) 290 VAC/3Ø (for 460 motors) for a minimum of five (5) seconds,
the motor will automatically switch off and an alarm condition (NO AIRFLOW) will be energized
and displayed. If the power supply voltage returns to the correct values, the motor will
automatically restart.
NOTICE: The unit’s control panel (dap4™) has a time delay before the NO
AIRFLOW alarm is energized. It is adjustable from 5 to 180 seconds (in 5
second increments). On site where a voltage problem is known to exist, the
delay can be adjusted to eliminate “nuisance” alarms until the problem is
corrected.
EC Motor Testing
To test the plenum fan modules in manual mode, wire a 9-volt battery across the plug fan
control signal (see schematic for wiring details). Be certain to disconnect both terminals (+ and
-) from the analog output. This will enable the fan control signal at approximately 90%. The
fans will spin at near full speed if the contactors are enabled.
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