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Frequency Converter and Mot...
the current should be zero. A frequency converter with a
defective current sensor will indicate some current flow. An
indication of a fraction of one amp is tolerable. However,
that value should be considerably less than one amp. If the
display shows more than one amp of current, there is a
defective current sensor.
To determine which current sensor is defective, measure
the voltage offset at zero current for each current sensor.
See the current sensor test procedure.
5.3 Electromagnetic Interference
5.3.1 Effect of EMI
The following is an overview of general signal and power
wiring considerations when addressing the Electro-
magnetic Compatibility (EMC) concerns for typical
commercial and industrial equipment. High-frequency RF
emissions and immunity are discussed. Compliance to
national and European CE EMC directives are required.
While electromagnetic interference (EMI) related distur-
bances to frequency converter operation are uncommon,
the following detrimental EMI effects may be seen:
Motor speed fluctuations
Serial communication transmission errors
Drive CPU exception faults
Unexplained frequency converter trips
A disturbance resulting from other nearby equipment is
more common. Generally, other industrial control
equipment has a high level of EMI immunity. However,
non-industrial, commercial, and consumer equipment is
often susceptible to lower levels of EMI. Detrimental effects
to these systems may include the following:
Pressure/flow/temperature signal transmitter
signal distortion or aberrant behaviour
Radio and TV interference
Telephone interference
Computer network data loss
Digital control system faults
High Power Service Manual for Modular F Frame Drives
®
MG90K202 - VLT
is a registered Danfoss trademark
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