# Must PLC be inside a box?



## MDShunk (Jan 7, 2007)

I have a job coming up where I pushed for, and received, permission to mount the PLC in the server room. This will be an A-B ControlLogix that will only have a few communication modues plugged into it to talk to some other PLC racks elsewhere in the building and a new MCC lineup with communicating VFD's. Must this PLC rack be inside an enclosure, or can I compliantly just hang it on the wall?


----------



## Jlarson (Jun 28, 2009)

All 24 volt power, and some ethernet or modbus? I would say go for it.


----------



## MDShunk (Jan 7, 2007)

Jlarson said:


> All 24 volt power, and some ethernet or modbus? I would say go for it.


Yeah. Mostly ethernet, and some legacy data highway. One rs-485. No i/o whatsoever in this rack. Just communications.


----------



## Jlarson (Jun 28, 2009)

MDShunk said:


> Yeah. Mostly ethernet, and some legacy data highway.


I wouldn't see how it would be any different from any network gear.


----------



## MDShunk (Jan 7, 2007)

Jlarson said:


> I wouldn't see how it would be any different from any network gear.


The power supply connections are what concerns me. Just didn't know if anyone's done such a thing before (PLC without an enclosure).


----------



## Jlarson (Jun 28, 2009)

MDShunk said:


> The power supply connections are what concerns me. Just didn't know if anyone's done such a thing before (PLC without an enclosure).


Never done it but have thought about it. If it's a 24 VDC one I would set an outlet and plug in a power supply.


----------



## mattsilkwood (Sep 21, 2008)

MDShunk said:


> *The power supply connections are what concerns me.* Just didn't know if anyone's done such a thing before (PLC without an enclosure).


 I would say no for this reason.


----------



## MDShunk (Jan 7, 2007)

mattsilkwood said:


> I would say no for this reason.


Yeah, but I can get a wall wart or enclosed power supply. I don't have to use the typical din rail open power supply.


----------



## TOOL_5150 (Aug 27, 2007)

I see no problem. T1's and the like have 24V wall wart power supplies [damn things fall out all the time and then the customer bitches that noone can call out] and get mounted the exact same way. If your stupid enough to put your tongue to the PSU terminals.. then you deserve the shock, which wouldn't really be much of nothing anyway.

~Matt


----------



## BuzzKill (Oct 27, 2008)

Marc is asking a question? :blink:


----------



## John Valdes (May 17, 2007)

I say your fine. Just protect the incoming power connections. I like the idea of the cord and plug. After all it is in a very clean environment and that would have been my sole concern.


----------



## IMM_Doctor (Mar 24, 2009)

*Nope - Read the instructions*

This equipment is supplied as open-type equipment. It must be mounted within an enclosure that is suitably designed for those specific environmental conditions that will be present and appropriately designed to prevent personal injury resulting from accessibility to live parts. The enclosure must have suitable flame-retardant properties to prevent or minimize the spread of flame, complying with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if non-metallic. The interior of the enclosure must be accessible only by the use of a tool. Subsequent sections of this publication may contain additional information regarding specific enclosure type ratings that are required to comply with certain product safety certifications.​​


----------



## MDShunk (Jan 7, 2007)

IMM_Doctor said:


> This equipment is supplied as open-type equipment. It must be mounted within an enclosure that is suitably designed for those specific environmental conditions that will be present and appropriately designed to prevent personal injury resulting from accessibility to live parts. The enclosure must have suitable flame-retardant properties to prevent or minimize the spread of flame, complying with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if non-metallic. The interior of the enclosure must be accessible only by the use of a tool. Subsequent sections of this publication may contain additional information regarding specific enclosure type ratings that are required to comply with certain product safety certifications.​​


I'm not sure that the instructions necessarily have the force of law, or they're just the manufacturer's idea of a good practice.


----------



## Jlarson (Jun 28, 2009)

IMM_Doctor said:


> This equipment is supplied as open-type equipment. It must be mounted within an enclosure that is suitably designed for those specific environmental conditions that will be present and appropriately designed to prevent personal injury resulting from accessibility to live parts. The enclosure must have suitable flame-retardant properties to prevent or minimize the spread of flame, complying with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if non-metallic. The interior of the enclosure must be accessible only by the use of a tool. Subsequent sections of this publication may contain additional information regarding specific enclosure type ratings that are required to comply with certain product safety certifications.​


That is cheap, the instructions aren't real code (STFU UL purists). They are more like guidelines than rules. I have seen an install like MD wants to do once or twice.


----------



## MDShunk (Jan 7, 2007)

Jlarson said:


> That is cheap, the instructions aren't real code (STFU UL purists). They are more like guidelines than rules. I have seen an install like MD wants to do once or twice.


"listing and labeling", to me, would seem to indicate that any special rules be part of the UL listing for that type of device (they aren't), or they must be on an actual label (they aren't).


----------



## John (Jan 22, 2007)

Put it in a an enclosure to keep it from prying eyes and people accidently "Bumping "it.
Here's one that I did for a energy management wireless comunication control. 
View attachment 4302


----------



## John Valdes (May 17, 2007)

John said:


> Put it in a an enclosure to keep it from prying eyes and people accidently "Bumping "it.
> Here's one that I did for a energy management wireless comunication control.
> View attachment 4302


If that's (John's Pic) what your talking about I say you need the enclosure. I was thinking a simple rack or module with a few I/O. The module type would for sure be fine IMO. But if you need the other items as pictured I would put it all in a box.


----------

