exothermic weld

[jmgreer]

hello, this is my first time to ask a question on the forum. my question is in regard to a inspector directing me to use a exothermic weld to connect my egc to the structural steel. the print directs me to install per nec 250.30. it is a single seperately derived system and i used a mechanical lug to make this connection. would someone direct me to the artical in the code that says that a exothermic weld is the only acceptable means for this connection. thank you

 

[acrwc10]

250.8(A)

Unless the connection is not accessible you would not need to "exothermic weld" it.

 

[earlejohnson]

does it spec on the prints

 

[jmgreer]

no, on the transformer schedule it says to install per nec 250.30.

 

[Smart $]

no, on the transformer schedule it says to install per nec 250.30.

250.30 does not cover connection of GEC's.

250.8 does.

250.8 Connection of Grounding and Bonding Equipment.

(A) Permitted Methods. Grounding conductors and bonding jumpers shall be connected by one of the following means:
(1) Listed pressure connectors
(2) Terminal bars
(3) Pressure connectors listed as grounding and bonding equipment
(4) Exothermic welding process
(5) Machine screw-type fasteners that engage not less than two threads or are secured with a nut
(6) Thread-forming machine screws that engage not less than two threads in the enclosure
(7) Connections that are part of a listed assembly
(8) Other listed means

A 2011 proposal was made to elaborate on the types of grounding conductors permitted. It was accepted at the ROP stage and will likely be incorporated.

 

[Jim W in Tampa]

If not required by specs then ask him to site code number to require it. I only used mechanical clamps