Baldor MicroFlex, Installation Manual

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3-10 Basic Installation MN1919
3.4 Power connections
This section provides instructions for connecting the AC power supply.
The installer of this equipment is responsible for complying with NEC (National Electric Code)
guidelines or CE (Conformite Europeene) directives and application codes that govern wiring
protection, earthing/grounding, disconnects and other current protection.
DANGER : Electrical shock can cause serious or fatal injury. Do not touch any
power device or electrical connection before you first ensure that
power has been disconnected and there is no high voltage present
from this equipment or other equipment to which it is connected.
MicroFlex drives are designed to be powered from standard single and three-phase lines that
are electrically symmetrical with respect to earth/ground. The power supply module within all
MicroFlex models provides rectification, smoothing and current surge protection. Fuses or
circuit breakers are required in the input lines for cable protection.
Note: A Residual Current Device (RCD) must not be used for fusing the drive.
An appropriate type of circuit breaker or fuse must be used.
All interconnection wires should be in metal conduits between the MicroFlex, AC power
source, motor, host controller and any operator interface stations. Use UL listed closed loop
connectors that are of appropriate size for the wire gauge being used. Connectors are to be
installed using only the crimp tool specified by the manufacturer of the connector.
3.4.1 Earthing / grounding
A permanent earth/ground bonding point is provided on the heatsink, which must be used as
the protective earth. It is labelled with the protective earth symbol in the casting and does not
form any other mechanical function.
Connector X1 contains earth terminals, but these must not be used as protective earth since
the connector does not guarantee earth connection first, disconnection last. Earthing methods
are shown in section 3.4.2.
Note: When using unearthed/ungrounded distribution systems, an isolation transformer
with an earthed/grounded secondary is recommended. This provides three-phase
AC power that is symmetrical with respect to earth/ground and can prevent
equipment damage.
3.4.1.1 Protection class
User protection has been achieved using Protective Class
I
(EN61800-5-1, 3.2.20), which
requires an earth connection to the unit whenever hazardous voltages are applied. The
equipment provides protection against electric shock by:
H
Means of connection of protective earth to accessible live conductive parts.
H
Basic insulation.
3.4.1.2 Earth leakage
Maximum earth leakage from the MicroFlex is 3.4mA per phase (230V 50Hz supply). This
value does not include the earth leakage from the AC power filter, which could be much larger
(see section A.1.3). If the MicroFlex and filter are mounted in an enclosure, it is recommended
the enclosure is earthed using a 10mm
2
conductor.