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7.2 TESTING
To test the plug fan modules in manual mode, turn on blower and fan speed switch on manual over-
ride module. This will enable the fan control signal at maximum. The fans will spin at near full speed
if the contactors are enabled.
7.3 PROTECTIVE FEATURES
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 detection,
Under-voltage detection,
Short-circuit protection.
If any of the conditions exist, the motor stops electronically and an alarm (NO AIRFLOW) will be
energized and displayed on the unit’s microprocessor screen. The motor will start up automatically.
To reset, the power supply has to be switched OFF for a minimum of twenty seconds.
If for any reason the rotor is blocked, the motor will electronically switch off. Before looking
for any blockage make certain to power down the unit. Once the blockage is cleared the
motor will automatically restart when powered on.
ECmotorshaveundervoltageprotection.Ifthepowersupplyvoltagefallsbelow˜150VAC/3Φ(for
230voltmotors)or˜290VAC/3Φ(for460voltmotors)foraminimumofve(5)seconds,themotor
will automatically switch off and an alarm (NO AIRFLOW) will be energized and displayed. If the
power supply voltage returns to the correct values, the motor will automatically restart.
NOTE: 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 sites
where a voltage problem is known to exist, the delay can be adjusted to eliminate “nui-
sance” alarms until the problem is corrected. See Menu K (ALARMS and LIMITS), (NO
AIR FLOW ALARM TIME DELAY) in the operation manual.
7.4 MAINTENANCE
Maintenance is not required on EC motor/plug fan modules. The motors are sealed, have mainte-
nance free ball bearings and permanent lubrication. The only acceptable service is replacement.
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