Re: Request for comment - G320 wiring part II

Hi Alan

With servo drives NEVER NEVER power up drives without mechanically
operated Dead Stop switches fitted outside the limit switches. Must
be normally closed so that if a wire gets cut every thing fails safe.
Wire all the switches in series operating a contactor that provides
power to the drives. Where you switch the motors off with the
contactor( betweeen drive and motor or in power circuit to drive )
depends entirely on the drive. Mariss will advise where best with
Gecko's. It must stop the motors as quickly as possible. The E stop
switch should also kill the same contactor. Position the switches so
that the slide is virtually stationary when you reach the end of
movement if you trip a dead stop while traversing at maximum rate.

Quite a few machines have Buffer Stops that dissipate any residual
energy. This enables you to fit the dead stops closer to end of
traverse.

Dead stop circuits and Estop push button must not rely on electronics
in any way unless using a special E stop relay (V. Expensive)

This is Mandatory on all servo driven machines in Europe and believe
me can save a great deal of expense shuld you ever get a servo
runaway.

Regards

Ian Eagland

Eagland Machine Tools UK