
B-63943EN/02 9.STOP AND EMERGENCY STOP
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Cautions for configuring an emergency stop circuit in compliance with safety standards
To configure an emergency stop circuit in compliance with JIS safety
standards(*), observe the following cautions. Compliance with these
JIS safety standards is a prerequisite for complying with the EC
Machine Instructions.
The method for shutting off the motor power section in the amplifier
is based on an IGBT (transistor) rather than an electromechanical
scheme.
When configuring an emergency stop circuit, therefore, install a line
contactor on the power input line for motor power in the power supply
module in order to ensure electromechanical shut-off, and apply
voltage to the control coil of the contactor via the contactor control
output of the power supply module.
A failure in the amplifier may disable the output relay of the power
supply module from going off, thus preventing the line contactor from
shutting off the power, even when the emergency stop command input
(*ESP) of the amplifier becomes low.
To secure motor power shut-off, design the emergency stop circuit in
a redundancy configuration. To be specific, the emergency stop circuit
must have a direct line contactor shut-off route based on an emergency
stop switch that is independent of the shut-off function of the
amplifier.
If a spindle amplifier module is used, shutting off the motor power
line during spindle rotation disables the spindle from stopping quickly
because the power regenerative function does not work, allowing the
spindle to coast. So, provide the redundancy circuit mentioned above
with a delay function based on an off-delay timer that allows a usual
stop time.
Refer to the following material for detailed descriptions about cautions
related to safety circuits.
A-71429-S13J:
About Requirements for Safety Circuits and Configuration
Samples
To get a copy of this material, contact your FANUC sales
representative.