Vents VKPF, Руководство пользователя

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VKP/VKPI/VKPF/VKPFI
2. The motor cannot start the mechanism with DOL starting.
Typical symptoms:
The motor fails to turn or “freezes” at certain speed which is maintained until actuation of the protection suite.
Solution:
This problem may not be solved with an SS device. The motor develops insufficient shaft torque. However, this problem can
be addressed by using an FC, but each case may be different.
3. The motor spins up the mechanism with authority, but fails to reach the rated rotation speed.
Typical symptoms:
The input automatic circuit breaker is tripped during spin-up. This often happens with heavy-weight fans with a
considerable rotation speed.
Solution:
Such problems may be addressed with an SS device, but not with 100 % certainty. The closer the motor speed to the rated
value during the actuation of the protective equipment, the higher the chances of success. The use of an FC in this case helps solve the
problem fundamentally.
Standard switching equipment (automatic circuit breakers, contactors and motor starters) is not designed to withstand
prolonged overloads normally causing the fan to shut down automatically DOL starting that continues for a long period of
time.
Using switching equipment with a higher maximum current rating renders the electric motor protection system less sensitive.
As a result the switching equipment will not be able to detect motor overload in time due to a high current sensing threshold.
Such problems as mentioned above can only be addressed by utilizing a soft starter or a frequency converter to start the fan.
MAKE SURE THAT THE FAN IMPELLER ROTATES IN THE DIRECTION MARKED BY THE
ARROW ON THE FAN CASING.
IF NECESSARY, CHANGE THE IMPELLER ROTATION DIRECTION BY ALTERING THE PHASE
SEQUENCE ON THE ELECTRIC MOTOR TERMINALS.
Prior to performing any technical maintenance and repair disconnect the fan from the electric mains and wait until its rotating parts
come to a complete stop.
The technical maintenance includes periodic cleaning of the surfaces from accumulated dust and dirt.
Use a soft brush or compressed air to remove dust from metal surfaces of the fan. Use a vacuum cleaner to remove dust from the sound
insulating surface.
The impeller blades require thorough cleaning once in 6 months.
Detach air ducts from the fan before starting maintenance works.
Clean the impeller blades with a soft cloth wetted in mild water detergent solution. Avoid liquid dripping on the motor.
Wipe the fan surfaces dry after cleaning.
While cleaning the fan make sure the balance counterweights are not shifted and the impeller is not misaligned.
DISCONNECT THE UNIT FROM POWER SUPPLY BEFORE ANY MAINTENANCE
OPERATIONS!
ENSURE THAT THE UNIT IS SWITCHED OFF FROM THE SUPPLY MAINS BEFORE
REMOVING THE GUARD.
TECHNICAL MAINTENANCE