electrical design questions

Status
Not open for further replies.
J

james_mcquade

Senior Member
Hi all,

I had a rush meeting with a customer i regards to some work he wants an i left my code book behind.
I have 2 questions and would appreciate any help you can give.

#1 What is the code reference for conduit seals in regards to the fill size?
I remember reading its 25% but i cannot cite the code.

#2 What is the code reference for placing pneumatic valves in the same enclosure as the plc.
One valve will have water in the line and the other will have air to dry off the parts. i tole him its bad practice and
the consequences, but he wants book, chapter and verse.


thanks,
James
 
james_mcquade said:
Hi all,

#2 What is the code reference for placing pneumatic valves in the same enclosure as the plc.
One valve will have water in the line and the other will have air to dry off the parts. i tole him its bad practice and
the consequences, but he wants book, chapter and verse.


thanks,
James
Click to expand...
It's not prohibited by the NEC. NFPA79 does prohibit it, but is not something that is enforceable in any general way. UL allows such a cabinet to be listed.

I would not want to put them in the PLC cabinet either, but it would not bother me any to put them in a junction box hung off the side or bottom of the PLC cabinet.
 
james_mcquade said:
Hi all,

I had a rush meeting with a customer i regards to some work he wants an i left my code book behind.
I have 2 questions and would appreciate any help you can give.

#1 What is the code reference for conduit seals in regards to the fill size?
I remember reading its 25% but i cannot cite the code.
Click to expand...

If you are talking about seal offs for hazardous locations then the answer is the conductor fill for the seal off is 25% 501.15(C)(6) is the code reference for Class I Division I &II locations.

#2 What is the code reference for placing pneumatic valves in the same enclosure as the plc.
One valve will have water in the line and the other will have air to dry off the parts. i tole him its bad practice and
the consequences, but he wants book, chapter and verse.
Click to expand...

You might be thinking about 300.8, but that section does not deal with enclosures.

Chris
 
petersonra said:
It's not prohibited by the NEC. NFPA79 does prohibit it, but is not something that is enforceable in any general way. UL allows such a cabinet to be listed.

I would not want to put them in the PLC cabinet either, but it would not bother me any to put them in a junction box hung off the side or bottom of the PLC cabinet.
Click to expand...

Bob's reference
NFPA79:2007:11.2.2 Physical Separation or Grouping
except for integral part of listed equipment and are separated by suitable barriers.
ex: Laser head cooling systems.
 
Status
Not open for further replies.
Top