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If one of the fan internal safeties are triggered, the motor will stop (via electronic controls) and
an alarm (FAN FAILURE) will be indicated on the u
nit’s dap4 display controller screen.
Once the fan is stopped via internal controls, the motor will not restart automatically. The internal
electronic controller must be reset, by cycling the main electrical power supply. Switched the
electrical power to OFF for a minimum of sixty (60) seconds and then turned back on.
If for any reason the rotor is blocked, the motor will electronically switch off. Before looking for
blockage, make certain to disconnect all electrical power sources to the unit. Once the blockage
is cleared the motor will automatically restart when powered is turned back 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 electrical power supply voltage falls below
150 VAC/3Ø (for 208-230 VAC volt motors) 290 VAC/3Ø (for 380-480 VAC 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 electrical power supply voltage returns to the
correct values, the motor will automatically restart.
If any form of trouble-shooting service is required inside the fan motor terminal box, do not open
the plug fan terminal cover within the first 5 minutes after turning OFF the electrical power to the
unit.
9.17. Current Sensing Switch Adjustment (Plug Fans Only)
The current sensing relay is set at the factory and does not normally require adjustment in the
field. If the unit speed operating mode is change in the field, the current sensing switch may
require the no airflow alarm to be adjusted. Contact Data Aire Service for instructions regarding
current sensor adjustment.