Chapter: H.3. Installation
H.3. Installation
H.3.1. Safety principles
a. Leveling connections
Touch protection encompasses the automatic switching off of the power supply by means of the special short
circuit (differential type) or limitation of voltages which may be touched if the insulation is damaged to a level
not exceeding the permissible values.
Due to the intermediate circuit operation, a short to ground in the output circuit of the frequency converter
may not be detected by the short circuit protection. The frequency converter provides protection against short
circuits between the phases and the output, but this protection is based on putting the IGBT transistors in the
blocking state, which does not meet the requirements of fire protection.
In this regard, in order to ensure the staff safety, it is necessary to make local leveling connections in a
corresponding way.
The special, respectively designated and protected from corrosion points for connection of the leveling wires
are provided in the frequency converter.
b.
Protections
Usage of gG or aM fuses is allowed in the circuits, however taking into account necessity of protection of the
rectifier bridge of the frequency converter, the best solution is gR or aR fuses.
Frequency converter is protected from: drive overloading, motor overheating, under- and overvoltage
in an DC link circuit of the converter, a short-circuit at the converter output - it protects converter only!
c. The switching devices
To comply with the EU Directive, in accordance with PN-EN 60204-1: 2010, a device for switching off the
power must be provided in the motor controller system, which consists of a frequency converter and an
electric machine. This device must be one of the following:
•
a disconnector (with or without fuses), an AC-23B category of use that meets the requirements
EN
60947-3,
•
a disconnector (with or without fuses), which ensures disconnection of the load circuit by
opening the main contacts, complying with the requirements of EN 60947-3,
•
circuit breaker complying with EN 60947-2.
Fulfilment of the requirements is the responsibility of the organization performing the installation.
d. Emergency stop
To comply with the EU Directive, in accordance with PN-EN 60204-1: 2010, on the basis of the staff and
equipment safety, it is necessary to use an emergency stop switch, which has an advantage over other
functions, regardless of the operation mode. The STOP key on the operator panel cannot be considered as
an emergency stop switch, because pressing it does not turn off the frequency converter from the power
supply.
Fulfilment of the requirements is the responsibility of the organization performing the installation.
e. Housing
The housing meets the requirements of IP00 degree of protection. The housing is designed in such a way
that it cannot be removed without the use of tools.
f. Discharging capacitors
There is a battery of relatively large capacitors in the intermediate circuit of the frequency converter. After
turning off the supply voltage of the frequency converter, dangerous voltage is held at its terminals for a
certain time. It is necessary to wait 10 min. before switching at the terminals of the power terminal
connections of the frequency converter. Information about the danger of such a voltage is on the panel, which
closes the terminal connections of the supply voltage.
H.3.2. Electromagnetic Compatibility (EMC)
The installation principles reducing EMC problems are divided into four groups. To achieve full success it is
necessary to apply all principles listed below. Not applying to one of principles ruins the effect of others.
•
separation,
•
equalizer connections,
•
shielding,
•
filtration.
MFC1000AcR, TWERD Power Electronics
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