Over 600V Substation Installation Requirements

Status
Not open for further replies.
M

minesh21

Senior Member
Location
CA USA
I am installing a 4160V to 480V substation and have a question about 110.31. This enclosure is going outside in a fenced area. I think it is pretty clear that I need to conform to Table 110.31. But my assumption is the 10'-0" requirement only pertains to the front and rear of the equipment (since the equipment is front and rear access only) and does not apply to the sides. So I may have the fence right up against the sides no problem, but need the 10'-0" clear in the front and back. Is my interpretation correct?

Also, I believe I must comply with 110.31(C)(2) because the fence is locked, but I'm confused why it references 110.34, 110.36 and 490.24 and does not mention 110.32, 110.33 or 110.40. I'm assuming I still need to comply with 110.32 and 110.33, even though 110.31(C)(2) leaves these sections out. Is this correct?

Lastly, what is the difference between 110.31(C)(1) and 110.31(D)?

Forgot to add this -

110.33(A)(3) - Does this apply to gated and fenced areas?
 
Last edited:
Lots of good questions. Do you have limited space to work with?

110.31 is correct, but non-typical. Typically this distance is used around the entire equipment. It is the right thing to do.

The other articles referenced play to the equipment and working clearances, not to the fence separation. Recall, 110.30. There are exits to think about and general equipment maintenance for ability to replace.
 
publicgood said:
Lots of good questions. Do you have limited space to work with?

110.31 is correct, but non-typical. Typically this distance is used around the entire equipment. It is the right thing to do.

The other articles referenced play to the equipment and working clearances, not to the fence separation. Recall, 110.30. There are exits to think about and general equipment maintenance for ability to replace.
Click to expand...

Yes I have limited space. I can give 10 feet in front and back. I don't have the side clearance because of existing canopy supports.
 
Okay so we have decided to remove the fence and pad lock all the equipment. The code does not require to put a wall or fence enclosing the gear correct? The requirement for 10-0" spacing in my case was only IF I put a wall, screen or fence around the equipment right? So now I just need to comply with working space around the equipment and I'm good?
 
minesh21 said:
Okay so we have decided to remove the fence and pad lock all the equipment. The code does not require to put a wall or fence enclosing the gear correct? The requirement for 10-0" spacing in my case was only IF I put a wall, screen or fence around the equipment right? So now I just need to comply with working space around the equipment and I'm good?
Click to expand...

If you follow 110.31(D). Right, working clearance and equipment ventilation then. Consider vehicle barriers. Also confirm working clearance is double or you have egress from working space on both sides of the equipment. Depending on type of terminations you may consider greater than working clearance for hot stick. You might also confirm equipment may be replaced.
 
publicgood said:
If you follow 110.31(D). Right, working clearance and equipment ventilation then. Consider vehicle barriers. Also confirm working clearance is double or you have egress from working space on both sides of the equipment. Depending on type of terminations you may consider greater than working clearance for hot stick. You might also confirm equipment may be replaced.
Click to expand...

Yes I have working clearances, but I am arguing my egress is unobstructed because you can get to the door by going on either side of the lineup. So if there is a fire on the north side you can go around the gear on the south side to exit. Therefore, I don't need two doors.

Also, since we have a gate we don't need any additional barriers (the gate is the barrier). We just don't have 10'-0" all around the equipment, but we have enough for the normal working space requirements in 110.34. We will keep the gates as is.
 
publicgood said:
If you follow 110.31(D). Right, working clearance and equipment ventilation then. Consider vehicle barriers. Also confirm working clearance is double or you have egress from working space on both sides of the equipment. Depending on type of terminations you may consider greater than working clearance for hot stick. You might also confirm equipment may be replaced.
Click to expand...

I realized my previous response may need context. We are keeping the fence and arguing since we don't need a fence clearance per 110.31(D) we can still have a fence that is closer than 10'-0" but further than 5'-0" (working clearance).
 
minesh21 said:
I realized my previous response may need context. We are keeping the fence and arguing since we don't need a fence clearance per 110.31(D) we can still have a fence that is closer than 10'-0" but further than 5'-0" (working clearance).
Click to expand...

Based on what you’ve described, sounds compliant
 
Status
Not open for further replies.
Top