Technical information

vii
Safety Considerations
You have the responsibility to comply with the safety requirements of your system. This
includes installing your system with an appropriate master disconnect switch for emergency
shut down using the proper wire and, if necessary, a properly sized transformer.
You can separate the logic AC power and the bridge AC power so that only the bridge AC
power is removed when an interlock or emergency stop switch is activated. This arrangement
allows the FX drive to retain the motor position in memory when power is removed from the
motor. This makes, a home move unnecessary after bridge power is restored. Remember, it
is up to you to determine if this is a safe configuration.
Failure to follow safe installation guidelines can cause death or serious injury. You are
responsible for providing emergency interlock switches that will remove AC power from
the system any time the emergency stop is activated. The safety ground connections
should only be disconnected for servicing, and only after all AC power has been removed.
Even after the removal of AC power, there is still stored energy in the drives that must be
dissipated before servicing. Wait a minimum of eight minutes after removing AC power
before servicing 230V drives.
The typical bus dissipation time to less than 40 volts is four minutes. Forty (40) volts is
considered a safe voltage level by UL (Underwriters Laboratories, Inc.); however, this is still
enough power to rotate the motor shaft. Dissipation to less than 40 volts can take longer than
4 minutes if a fault condition exists that causes the bridge to be disabled during the dissipation
time. The time it takes to dissipate the energy in the bus capacitance greatly depends on the
torque and speed being produced when external power is removed (i.e., the current being
drawn out of the capacitors).
"External Disconnect Example (FX-6200 through FX8400)" on the following page shows
how to remove the AC power if the bridge and logic power are wired separately on the FX-
6200 through FX-8400. If the logic power is wired separately, the logic AC power switch
must be set to the AUX position before power is applied. The FX-6200 through FX-8400
drives are shipped from the factory with this switch in the Main position.
Example Reference Manual