3.8 External Interlock
3.8
External Interlock
Systems that may be affected during drive fault conditions should be interlocked with the drive fault output and ready
signal.
u Drive Ready
When the "Drive ready" signal has been set to one of the multi-function contact outputs, that output will close whenever
the drive is ready to accept a Run command or is already running. Under the following conditions the Drive ready signal
will switch off and remain off, even if a Run command is present:
• when the power supply is shut off
• during a fault
• when there is problem with the control power supply
• when a parameter setting error makes the drive unable to run even if a Run command has been entered
• when a fault such as overvoltage or undervoltage is triggered as soon as the Run command is entered
• when the drive is in the Programming mode and will not accept a Run command even when entered
Interlock Circuit Example
n
In some cases external signals other than the configuration signals of the drive are required as a condition for the drive to
run.
In such cases, in addition to the ready conditions stated above, input these external interlock signals to the drive to use
them as external interlock signals.
If any condition for these external interlock signals is not satisfied, the drive stops.
An example circuit configuration is shown in
Figure 3.21
Run command
Primary panel on
External interlock established
External Interlock established
Secondary panel on
Motor temperature normal
Example of interlock
signal input
<2>
<1> "External interlock" signifies conditions where machinery or equipment could be damaged if the drive or motor is run outside
the scope of its specifications.
<2> Always allocate necessary signals for protecting the system as external interlock signals.
Examples: Machine lubrication unit normal (N.O. contact) or emergency stop normal (N.O. contact).
104
Figure
Drive
Drive internal
circuit
<1>
<1>
Figure 3.21 Interlock Circuit Example
3.21.
Schematic for the drive's internal circuit
Interlock signal input
Run command
Figure 3.22
YASKAWA ELECTRIC TOEP C710687 02B FSDrive-MV1000 Instructions
Drive ready
Drive ready
circuit
Run
command