What would you do

[Don R]

I found this problem at work my suppervisor is not an electrician and I want some feed back for him. There is a metal conduit with 10-18 # 10 thhn wires in a slab,they come into a metal box and branch out in runs of emt.One of the circuits kept triping the breaker until more than likely burnt in half. what should be done to fix this.
A) pull all the wires out to check them and replace the broken one
B) pull only a new wire in to replace the one you know is damaged
C) abandon the broken wire, run a new conduit, pull new wire to replace the damaged one,and do nothing to the rest of the wires.
Forgot to mention its a two part question. Does any of this create a hazard where some one could get hurt.
I would run a new conduit and replace all the wires, or pull all them out check them, replaceing the damage ones.I think there could be more than one damaged which could energise the conduit.

 

[sameguy]

I found this problem at work my suppervisor is not an electrician and I want some feed back for him. There is a metal conduit with 10-18 # 10 thhn wires in a slab,they come into a metal box and branch out in runs of emt.One of the circuits kept triping the breaker until more than likely burnt in half. what should be done to fix this.
A) pull all the wires out to check them and replace the broken one
B) pull only a new wire in to replace the one you know is damaged
C) abandon the broken wire, run a new conduit, pull new wire to replace the damaged one,and do nothing to the rest of the wires.
Forgot to mention its a two part question. Does any of this create a hazard where some one could get hurt.
I would run a new conduit and replace all the wires, or pull all them out check them, replaceing the damage ones.I think there could be more than one damaged which could energise the conduit.

1) How big is the pipe?
2) 10 or 18 wires?
3) What are the loads served by the wires?
4) Are they home runs?
5) What is the amp draw of each home run?

 

[Don R]

what would you do

what would you do

They are home runs, they feed general use receptacles and some lighting. The conduit is 1 1/4 rigid , they are on 20amp breakers, amp draw 5 - 12 amps

 

[eric9822]

How long is the run? If not to long we would probably just pull in all new.

 

[kwired]

I found this problem at work my suppervisor is not an electrician and I want some feed back for him. There is a metal conduit with 10-18 # 10 thhn wires in a slab,they come into a metal box and branch out in runs of emt.One of the circuits kept triping the breaker until more than likely burnt in half. what should be done to fix this.
A) pull all the wires out to check them and replace the broken one
B) pull only a new wire in to replace the one you know is damaged
C) abandon the broken wire, run a new conduit, pull new wire to replace the damaged one,and do nothing to the rest of the wires.
Forgot to mention its a two part question. Does any of this create a hazard where some one could get hurt.
I would run a new conduit and replace all the wires, or pull all them out check them, replaceing the damage ones.I think there could be more than one damaged which could energise the conduit.

I would get out the megger and use results of that to determine which of your solutions is best. If metal raceway is well bonded and intact the risk of energizing raceway is not very high, that is what the overcurrent protective device if for.

 

[Don R]

what would you do

what would you do

The run is around 100'. What If it's well bonded and intact, and one of the neutral wires are bad? The overcurrent device wouldn't work? You wouldn't know till you put a megger on them or pulled them out to check. I think that after shorting out in the conduit the chances of only one wire being damaged is slim. For every three circuits in the run there is a neutral.

 

[kwired]

The run is around 100'. What If it's well bonded and intact, and one of the neutral wires are bad? The overcurrent device wouldn't work? You wouldn't know till you put a megger on them or pulled them out to check. I think that after shorting out in the conduit the chances of only one wire being damaged is slim. For every three circuits in the run there is a neutral.

The megger may tell you if others are compromised. Really depends on why the first one went bad. If it was damaged before installation - maybe it is the only one damaged. If there is damage to raceway - maybe others are damaged. If raceway is damaged who says you don't damage new conductors when you pull them in? Megger is still a good start at determining next action.