Page 356 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

The inverters are designed to operate in an industrial environment where a high level of EMI can
be expected. Usually, good installation practices will ensure safe and trouble-free operation. If you
encounter problems, follow the guidelines stated below.

Actions toTake
Ensure that all equipment in the cubicle is well grounded using short, thick grounding cable connected to a
common star point or bus bar ,Make sure that any control equipment connected to the inverter (such as a PLC)
is connected to the same ground or star point as the inverter via a short,thick link Connect the return ground from
the motors,directly to the ground connection(PE) on the associated inverter.
Flat conductors are preferred as they have lower impedance at higher frequencies Terminate the ends of the
cables neatly, ensuring that unscreened wiresareas short as possible Separate the control Cables from the power
connections as much as possible,using separate trucking, if necessary at 900 right angles.Whenever possible,use
screened leads for the connections to the control circuitry
Ensure that contactors inside the cubicle are suppressed, either with R-C suppressors for AC contactors, flywheel,
diodes, for DC contactors fitted to the coils. Varistor suppressors are also effective. This is important when the
contactors are controlled from the inverter relay Use screened or armored connections for the motor connections
and ground the screen at both ends using cable clamps.

Warning
Safety regulations must not be compromised when The MM420 is supplied with a Status Display Panel(SP).
Default parameter settings cover the following requirements:
The motor rating data, Voltage, Current and Frequency are all compatible with the inverter data. (A standard
Siemens motor is recommended).
Linear V/f motors peed, controlled by an analogue potentiometer.
Maximum speed 3000rpm /minute with 50Hz, Controllable using a potentiometer via the inverter, analogue inputs
Ramp-uptime /Ramp-down time=10s
If more complex application settings are required, please refer to the parameter listing in the Operating Instructions.
For changing parameters you need one of the optional modules” Basic Operator Panel” (BOP), “Advanced
Operator Panel” (AOP) or communication options.
See Operating Instructions and Reference Manual.
Results:
Thus the installations of MicroMaster-420 from Siemens have been installed successfully.

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CITS : E & H - Electronics Mechanic - Exercise 231