# powerflex 40p help



## Hippie (May 12, 2011)

I don't understand. What do you mean about guard doors are they e-stops or are they powered by the drives?


----------



## michiganman (Oct 3, 2011)

the guard doors now are wired up the same as the 3 estops, the estops themselves might be pushed once a week, the gaurd doors are opened thousand times a day, the vfds are completely powered down and back up each time, causing the vfd's to fail, looking at ways to prolong vfd life
thanks


----------



## Netree (Sep 3, 2011)

The guarding doors should be wired differently, yes. You could control the output of the drives (output inhibit, safe-off option, etc.) with the guarding doors, and the emergency stop devices should only power off the drives.

Drives do not work okay when turned off/on many times like you have now.


----------



## Sawdust454 (Sep 26, 2008)

If you mean the safety rated input to the drive then yes. If it is not a safety rated input then it could be a safety concern, what category is the hazard?


----------



## Hippie (May 12, 2011)

How are the drives triggered on? If you're set up with 2/3 wire control remote that circuit can be run thru a 4 pole cube relay (1 pole for each drive) that will handle the estop circuit and stop the drives when needed but will not cut power from the drive


----------



## Hippie (May 12, 2011)

I think I may have misread and thought 4 drives. Still the theory is the same


----------



## John Valdes (May 17, 2007)

Sounds like time to write an SOP concerning the use of the doors. I am thinking you have CNC machines and they (operators) are opening the doors each time the machine is done with a part or when the part needs human attention. Is this correct? If so, you need to change the way the drives are wired. Or change how the operators do their job.
Or both.
Let the doors use the stop function instead of the E-Stop function. I cannot understand why they are opening doors instead of turning off the machine first. I would get that straightened out FIRST. Servos stop and start all the time. This is normal. Is the machine designed to use the doors to stop the machine?
I have seen machines where the doors will not open unless the machine is in stop mode. This is harder to do, but very effective.
A sign at the door stating "Do Not Open Doors With Machine Running" might work?

If your servos do not like to stop and start many times a day. It sounds like the product is not up to your standards.
Why not call the manufacturer or the distributor? They can help. If they cannot help I hate that you bought that equipment.


----------



## varmit (Apr 19, 2009)

The e-stops and guard doors are not NORMALLY required to initiate a "lockout " level safety condition. The e-stop string should only stop motion. I would rewire the e-stop string to be an enable input to the drives. If necessary, you can always have e-stop "zones" where opening a guard only drops out the moving equipment accessible from that particular access point.

I agree with John Valdes: There is some less than ideal operation procedures going on here.


----------



## michiganman (Oct 3, 2011)

The machine is at home and stopped 99% of the time when doors are opened. Looking at the best way to do this. Thanks


----------



## John Valdes (May 17, 2007)

michiganman said:


> The machine is at home and stopped 99% of the time when doors are opened. Looking at the best way to do this. Thanks


You are making no sense. At home? "And stopped 99% of the time when not opened"? I have no idea. :whistling2:


----------



## Netree (Sep 3, 2011)

I think he means only rarely are the doors opened when the machine is running. In this case, the doors switches could be wired in series with the stop control (terminal 1) on the drive at each station.


----------



## JRaef (Mar 23, 2009)

The "Safe Torque Off" input to the 40P will provide you with at least SIL2, it may even be SIL3 (I'm waiting for confirmation from a resource) without the need for another safety relay. So it could well be that you can, *if someone has determined that SIL2 (or SIL3) is appropriate*, wire the door switches to the VFD and then use the E-Stop safety circuit to do the power-off function and drop out the isolation contactors only when someone hits one of those buttons. That's the purpose of that feature.


----------



## michiganman (Oct 3, 2011)

Thanks, I will find out more info and post. Thanks again


----------



## RIVETER (Sep 26, 2009)

michiganman said:


> the guard doors now are wired up the same as the 3 estops, the estops themselves might be pushed once a week, the gaurd doors are opened thousand times a day, the vfds are completely powered down and back up each time, causing the vfd's to fail, looking at ways to prolong vfd life
> thanks


Do you not have "dynamic" braking resistors installed protecting the VFD"s?


----------



## oliquir (Jan 13, 2011)

i have worked on several cnc and none of them cut power to vfd when doors are opened, some of them locks the doors while machine is in operation and you have to stop it before it opens (for increased safety you could put a contactor in series with output of vfd but vfd must be stopped before contactor is opened)


----------

