Refeeding and splicing existing wires that are in concrete encase conduit

Status
Not open for further replies.
Tainted

Tainted

Senior Member
Location
New York
Occupation
Engineer (PE)
I am upgrading the electrical room and removing existing service switches. The existing service switches feed concrete encased conduits below.

I will refeed the concrete encased conduits with a new switchboard with service switches.

I want to put the switchboard behind the conduits where the conduits sweep up from the concrete. The problem is the conduits will impede the clearance of the switchboard.

Is there any easy way to get rid of the sweep and just make a handhole? How hard would it be to dig and make a underground splice box to reconnect all the wiring?



1708576338807.png
 
LarryFine said:
Do you know which direction they turn as it compares to where you wish they emerged?
Click to expand...
Don’t know unfortunately. The electrician and I were both scratching our head today trying to figure out and trace where it was going.

There are 9 conduits underground 3 per service switch
 
You may have to chop up some concrete just to see.

If you commit to doing so, you can reroute as needed.

Do you have enough headroom to build up the floor?
 
LarryFine said:
You may have to chop up some concrete.

Do you have enough headroom to build up the floor?
Click to expand...
I want to avoid building up the floor. Even if I did build up the floor I would still have to reconnect the feeders in the concrete encase conduit and splice them.

How does one chop concrete like this? I never seen it done to be honest

How would someone know how deep to go? Because they might accidentally cut the conduit underground
 
Tainted said:
Don’t know unfortunately. The electrician and I were both scratching our head today trying to figure out and trace where it was going.

There are 9 conduits underground 3 per service switch
Click to expand...
An underground tracer will locate each. Like the greenlee 501
 
If those old RMC's have been in the earth for a long time don't be surprised if you dig them up and find not much left of the old metal. IMO the only way to estimate and design this is to start with removing a small section of the floor to see what you're dealing with.
 
infinity said:
If those old RMC's have been in the earth for a long time don't be surprised if you dig them up and find not much left of the old metal. IMO the only way to estimate and design this is to start with removing a small section of the floor to see what you're dealing with.
Click to expand...

I think they are 60 years old. How long do conduits underground last?
 
infinity said:
If those old RMC's have been in the earth for a long time don't be surprised if you dig them up and find not much left of the old metal. IMO the only way to estimate and design this is to start with removing a small section of the floor to see what you're dealing with.
Click to expand...
If I want to get rid of those sweeps, do I need a floor mount splice box in handhole?
 
Tainted said:
If I want to get rid of those sweeps, do I need a floor mount splice box in handhole?
Click to expand...
That would be a good solution. Cut the elbows off and nipple into a pull box. From there continue underground to the new location.
 
infinity said:
That would be a good solution. Cut the elbows off and nipple into a pull box. From there continue underground to the new location.
Click to expand...
What kind of box handhole should I get? I don’t think it’s an off the shelf product based on how the existing conduits are laid out


If I have the handhole in front of the new switchboard, would that be a 110.26 issue? Reason I ask is because if someone removed the handhole cover, then there will be a giant opening in front of the new switchboard
 
JoeStillman said:
Why not put a pull box on the floor on top of the pipes and mount your switchboard on top of the pull box?
Click to expand...
The switchboard is getting move back so the conduits, if left in their original location, will be in front of the new switchboard.
 
JoeStillman said:
Why not put a pull box on the floor on top of the pipes and mount your switchboard on top of the pull box?
Click to expand...
Wouldn’t that violate 110.26, what’s the max height that a switchboard can be off the floor?

See infinity’s post. But i may consider this option if i exhaust my options
 
Tainted said:
Wouldn’t that violate 110.26, what’s the max height that a switchboard can be off the floor?

See infinity’s post. But i may consider this option if i exhaust my options
Click to expand...
Switchboards can be any height you want, as long as an appropriate work platform is constructed in front of them. You may be thinking of the maximum height to an OCPD handle of 6'7".
 
jim dungar said:
Switchboards can be any height you want, as long as an appropriate work platform is constructed in front of them. You may be thinking of the maximum height to an OCPD handle of 6'7".
Click to expand...
I don’t think a platform is suitable for this place. It’s also an obstruction of egress, someone can trip and fall
 
electrofelon said:
In their existing location, and if they stay, how far in front of the switchboard will these conduits be?
Click to expand...
About 2 feet. In NYC, if service is 1000kVA or more, service switchboard with service disconnect needs to have 5 feet of clearance
 
Status
Not open for further replies.
Top