palletizer cell, been down since the shift change. safety relay is a guardmaster msr127rp. friday day shift swapped the k2 contactor because the coil burnt, stores gave them a 100 c09 with the same coil voltage and they wired a1 a2 and the three poles like the old one.
now it wont reset. power led on, ch1 and ch2 leds on, k1 and k2 leds off, all e-stops pulled, both doors closed. press reset, nothing.
i metered 24.0v at a1 a2 and 24v on both channels, and s33 to s34 with the reset button held in reads open, which i dont get. day shift left a note saying jumper the feedback terminals to prove the relay is dead. im not doing that.
edit: forgot to say, no other faults on the panel today, photo of the relay and the new contactor attached. is it dead, any help would be appreciated?
One question. What's the wire number on S33, and where does the drawing say it goes before it gets to the button? Follow it on paper, not in the panel.
wire 412 off s33. drawing says 412 goes to k1 terminals 21 22, then 413 to k2 terminals 21 22, then 414 up to the reset button, then s34. on the old k2 the 21 22 was on a little block clipped to the front. new 100 c09 has nothing on the front. just coil and the three poles. day shift didnt move the block over, its in the scrap bin probably.
Then the drawing is right and the panel is wrong. That's your open loop.
so the relay wants to see that block closed before it resets, i think. the right block is a week out and i have a supervisor standing here asking when the cell runs, im stuck. whats the proper way back, stores is full of contactors.
Right to leave that note alone. A bridge across that loop resets beautifully, right up to the day K2 welds shut and it still resets.
Your meter told you why. The loop runs S33, NC on K1, NC on K2, reset button, back to S34, and it only closes with both contactors dropped out. The old K2 carried that NC on its front block, the new one carries nothing, so the loop is open at K2. The relay is doing its job.
You need an NC in that loop that is rated to prove the contactor. Look for the mirror contact symbol on whatever stores has in a D01 or a front mount aux, and whether it stands in that circuit is your safety person's call, not a night shift one.
stores had a 100 c09d01 on a different shelf, mirror symbol on the label. fitted it 06:00, 413 and 414 on the nc, k1 and k2 leds came on first reset.
turned out to be the contactor day shift fitted, nothing on it for the feedback loop, and the relay was refusing to reset because the loop sat open at k2 the whole time. our safety guy came in at 08:00, checked the symbol against what the drawing wants and signed it off before we ran anything. no bridge anywhere near it.
still dont know why the old block went in the bin, it would have clipped onto the new one. thanks pat_k and edj.
Drawing was right for once. Frame it.