Help with SensaGuard Switch 440N-Z21SS2H

[Ryan_Flowers]

Hello,

I'm adding an Allen-Bradley SensaGuard door switch (440N-Z21SS2H) to a small existing machine to drop out pneumatic function when the switch is open. This existing machine does not have any guardlogix and has a 1734-AENT point i/O with 24VDC Sink inputs controlling the pneumatics. I am having a problem getting a 24VDC input signal to the point I/O. I wired the unit with QD Cordset 889-F8AB-10. Wiring as follows:

Brown = +24VDC
Blue = 0V (or neg VDC?)
Red = +24VDC
Grey = Input to point I/O

Problem is that the sensing unit never stops flashing green and I don't get my 24VDC input to the point I/O when I change the switch state. The door is pretty small so this RFID switch works perfect form factor wise, so I'd like to not pivot. I also don't see why I would have to have a guardlogix or guardmaster device to land it on, but I guess I don't really know what my issue is.

Thanks for any help in advance.

 

[DarrylR]

If the indicator is blinking green it means the OSSD inputs aren't valid. I believe you need to have 24vdc on each line. (OSSD 1 and 2)

 

[plvlce]

For a safety circuit you really should be landing on at least safety relay(s), but that's not your immediate issue.

It is erroring because your OSSD inputs do not both have 24V (yellow and red wires).

You may also have to sink both the OSSD outputs -- I'm not familiar with this series of switch but I've encountered some safety devices that would fault if only one output was wired.

But if this is for a safety circuit you should be using them both anyways. If this is a situation where you need a safety-rated device such as this then a single wire to a non-safety input is certainly not sufficient.

 

[Ryan_Flowers]

I see ok, that cleared up the indicator problem. The I/O not changing state is from some crossed conductors on a QD hub for the entire equipment. So I need to check continuity and re-label.

Thanks