Emi Signal And Power Wiring; Effects Of Emi - Danfoss VLT FC 100 Service Manual

Adjustable Frequency Drive ...
To determine which current sensor is defective, measure
the voltage offset at zero current for each current sensor.
See chapter 6.4.12 Current Sensors Test.

5.2.3 EMI Signal and Power Wiring

The following is an overview of general signal and power
wiring considerations related electromagnetic compatibility
(EMC) for typical commercial and industrial equipment.
Only certain high-frequency phenomena (such as RF
emissions, RF immunity) are discussed. Low-frequency
phenomena (such as harmonics, AC line voltage imbalance,
notching) are not covered. Special installations or
compliance to the European CE EMC directives requires
strict adherence to relevant standards and are not
discussed here.

5.2.4 Effects of EMI

While electromagnetic interference (EMI) related distur-
bances to adjustable frequency drive operation are
uncommon, the following detrimental EMI effects
sometimes occur:
•
Motor speed fluctuations
•
Serial communication transmission errors
•
Adjustable frequency drive CPU exception faults
•
Unexplained adjustable frequency drive 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 include the following:
•
Pressure/flow/temperature signal transmitter
signal distortion or aberrant behavior
•
Radio and TV interference
•
Telephone interference
•
Computer network data loss
•
Digital control system faults
MG94A222
Service Manual
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
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