Siemens A1 User Manual
International English
Getting Started
MICROMASTER Applications Handbook
19
4.3.1 A
Typical
Installation
M
ISOLATOR
EMERGENCY
STOP
CONTACTOR
FUSE
INVERTER
Control
Connections
Supply
Figure 4-5
Typical Installation
Supply
The supply may be either single or three phase, depending on the
inverter type. The recommended wire sizes are stated in the
manual.
inverter type. The recommended wire sizes are stated in the
manual.
Isolator
An isolator is usually required for safety reasons.
Circuit
Breaker
or Fuses.
Breaker
or Fuses.
The protection rating is based on the input current as stated in the
manual. The input current is higher than the output current because
the form factor of the current is high. Do not use fast acting circuit
breakers or semiconductor fuses. Motor Circuit Breakers are usually
recommended for use with inverters.
Inrush currents on the latest inverters are typically equal to, or less
than the full load current, so nuisance tripping is less of a problem.
manual. The input current is higher than the output current because
the form factor of the current is high. Do not use fast acting circuit
breakers or semiconductor fuses. Motor Circuit Breakers are usually
recommended for use with inverters.
Inrush currents on the latest inverters are typically equal to, or less
than the full load current, so nuisance tripping is less of a problem.
Contactor
A contactor, with an emergency stop function connected may be
required both for auxiliary control and safety isolation. Do not use
the contactor as a stop start function This will cause unnecessary
wear on the contactor and there will always be a slight delay while
the inverter initialises. Use the control terminals or push buttons to
do this. It is not permitted to use the Run/Stop control of the inverter
as an emergency stop function. It is not recommended to fit a
contactor between the output of inverter and the motor.
required both for auxiliary control and safety isolation. Do not use
the contactor as a stop start function This will cause unnecessary
wear on the contactor and there will always be a slight delay while
the inverter initialises. Use the control terminals or push buttons to
do this. It is not permitted to use the Run/Stop control of the inverter
as an emergency stop function. It is not recommended to fit a
contactor between the output of inverter and the motor.
Motor
As shown in previous diagrams, many motors, particularly at low
powers, are designed for low voltage (230 V) or high voltage (400 V)
operation. The voltage is usually selected by fitting links at the motor
terminals. Instructions for low voltage (star) connection or high
voltage (delta) connection are usually shown on the inside of the
terminal cover. Clearly an inverter with a low voltage single or three
phase input will produce a low voltage three phase output, and the
motor should be connected accordingly. See also section 3.3
powers, are designed for low voltage (230 V) or high voltage (400 V)
operation. The voltage is usually selected by fitting links at the motor
terminals. Instructions for low voltage (star) connection or high
voltage (delta) connection are usually shown on the inside of the
terminal cover. Clearly an inverter with a low voltage single or three
phase input will produce a low voltage three phase output, and the
motor should be connected accordingly. See also section 3.3