Robot Safe Circuit Question

Attached is a segment of a robot safety circuit I am changeing. How do I get around this issue.

1827CRL = Robot Light Curtain
1727CRL = Operator Light Curtain
1927CRL = Leak Test Machine Home

Basic operation is Robot pics part from weld cell and places it in the leak tester.

So I want to Trip the safety circuit if the robot is breaking the light curtain and trying to place part on the leak tester when the operator is in his light curtain or if the leak tester is not home.

But if the Robot is not in the light curtain it should be ok to walk in and rotate the light curtain.

My worry is that when the robot is moving and breaks the light curtain even when the opertor and leak test are clear, the little delay inside the relay 1827CRL while it switches from N.O. to N.C.

What is the best way to get around this?


edit - My first idea would be to change the N.O. 1827CRL on the lower branch to 1727CRL and 1927CRL so if leak test and operator are clear then we don't care about robot light curtain. Had a little brain **** before. But anyways would anyone recommend anything different?

Safety first

Safety should always come first. No person(s) should ever be in an area where there is a potential of being in the path of moving equipment without equipment being locked out. What I have read in your post it seems that you want an operator to be able to adjust a light curtain when the robot is in a certain position at a certain time? Safeties should only be considered as a second line of defense, with a good lock out tag out program as the first line of defense to prevent injury or death. Let’s say that you get the system working the way you want, where the operator can make adjustments when the robot is in another position; what happens if something goes wrong with one of the light curtains or something goes wrong with the robot and it swings in the wrong direction at the wrong time and hits the operator; which could mean injury or death. What will OSHA say and what charges could be filed against your company? Neither you need to find a way for the operator to adjust the light curtain from a safe distance away from the path of the robot or a way to adjust the light curtain with the robot locked out. I bet it is not convenient and takes too much time to shut the robot down then start the line back up; but safety should never be second to production.

Sincerely:
Maintenance Man

Try this again.

See if I can explain it a little better this time, with a little more detail.

We have a weld cell that welds 10 parts together that are to heavy for a person to lift after they are fully assembled. So we have a leak tester placed behind the cell.

Layout from left to right since im not at work:
Weld cell, MH robot, Mh light curtain, leak test, operator light curtain.

MH light curtain is vertical to tell if MH is in or enterting leak test area,

On the other side is a horizontal light curtain to make sure the operator is not within 6 feet of the leak tester.

So it is a pretty safe setup.

My only concern was trying to tie into the robot safety circuit using the NO and NC of a really and the delay of when it switches states.

No operator adjusting of light curtains is going on