SEW-Eurodrive DRE 315, Operating Instructions Manual

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Operating Instructions – Explosion-Proof AC Motors – DRS/DRE/DRP 315
10
Motor malfunctions
Malfunctions
10 Malfunctions
10.1 Motor malfunctions
Malfunctions possible cause Remedy
Motor does not start up Supply cable interrupted Check the connections and (intermediate) terminal points,
correct if necessary )
Supply cable fuse has blown Replace fuse
Motor protection (switch) has triggered Check that the motor protection (switch) is set correctly;
current specification is on the nameplate
Motor protection does not trip Check motor protection control
Malfunction in control or in the control pro-
cess Observe the switching sequence; correct if necessary
Motor only starts with diffi-
culty or does not start at all Motor power designed for delta connection
but connected in star Correct the connection from star to delta; follow the wiring
diagram
Motor power designed for star-star connec-
tion but only connected in star Correct the connection from star to star-star; follow the
wiring diagram
Voltage or frequency deviate considerably
from setpoint, at least while being switched
on. Provide better power supply system; reduce the power
supply load;
Check cross section of supply cable, replace with cable of
larger cross section if needed.
Motor does not start in star
connection, only in delta
connection Star connection does not provide sufficient
torque If the delta inrush current is not too high (observe the reg-
ulations of the power supplier), start up directly in delta;
Check the project planning and use a larger motor or spe-
cial version if necessary (consult with SEW-EURODRIVE)
Contact fault on star/delta switch Check the switch, replace if necessary;
Check the connections
Incorrect direction of rotation Motor connected incorrectly Swap two phases of the motor supply cable
Motor hums and has high
current consumption Winding defective Send motor to specialist workshop for repair
Rotor rubbing
Fuses blow or motor protec-
tion trips immediately Short circuit in the motor supply cable Repair short circuit
Supply cables connected incorrectly Correct the wiring, observe the wiring diagram
Short circuit in motor Send motor to specialist workshop for repair
Ground fault on motor
Severe speed loss under
load Motor overload Measure power, check project planning and use larger
motor or reduce load if necessary
Voltage drops Check cross section of supply cable, replace with cable of
larger cross section if needed.