Aluminum main/system bonding jumper

[Boopizi]

New to the forums so i apologize if my question is in the wrong category or has been previously discussed.

My question: Is there somewhere in the code book that permits the use of an appropriate sized Aluminum wire as a main/system bonding jumper? It obviously states right in NEC 250.28(A) "Main bonding jumpers and system bonding jumpers shall be of COPPER or OTHER CORROSION-RESISTANT MATERIAL. To me that excludes Aluminum right off the bat. However I am finding other sources suggesting that only in a corrosive environment is Aluminum not permissible to use. So I must be missing something silly somewhere.

Any help is appreciated!

IAEI Magazine - "The main bonding jumper is permitted to consist of a wire, bus, screw or other suitable conductor. It must be fabricated of copper or other corrosion-resistant material. Aluminum alloys are permitted where the environment is acceptable."

 

[don_resqcapt19]

Aluminum is a corrosion resistant material....of course there are corrosives that attack aluminum but there are also corrosives that attack copper.

 

[kwired]

New to the forums so i apologize if my question is in the wrong category or has been previously discussed.

My question: Is there somewhere in the code book that permits the use of an appropriate sized Aluminum wire as a main/system bonding jumper? It obviously states right in NEC 250.28(A) "Main bonding jumpers and system bonding jumpers shall be of COPPER or OTHER CORROSION-RESISTANT MATERIAL. To me that excludes Aluminum right off the bat. However I am finding other sources suggesting that only in a corrosive environment is Aluminum not permissible to use. So I must be missing something silly somewhere.

Any help is appreciated!

IAEI Magazine - "The main bonding jumper is permitted to consist of a wire, bus, screw or other suitable conductor. It must be fabricated of copper or other corrosion-resistant material. Aluminum alloys are permitted where the environment is acceptable."

Last sentence that you quoted from IAEI answers your question.

It sort of becomes use of a material that is resistant to corrosive conditions present at the installation. Copper wouldn't fare so well in an area rich in anhydrous ammonia, not sure about aluminum in that environment but could be better. Many panel neutrals/ground bars where you may land the GEC and/or bonding jumper are aluminum alloys.

 

[Boopizi]

Wow! That answer really blows me away. Never would have considered aluminum a non-corrosive material. If that's the case it's strange that 250.28(a) specifically left out aluminum since it is so thorough in describing what is a permissible wiring method...

Thanks for answering my question,
-Austin

 

[infinity]

If it said only copper or aluminum that would leave out the green steel bonding screws used in most residential panels.

 

[kwired]

Wow! That answer really blows me away. Never would have considered aluminum a non-corrosive material. If that's the case it's strange that 250.28(a) specifically left out aluminum since it is so thorough in describing what is a permissible wiring method...

Thanks for answering my question,
-Austin

Corrosion is just a reaction between two elements of the periodic table of elements.

Most of the time we are talking about something that reacts with the metal elements when we use the word corrosion, but not all metals have same kind of reaction to same other elements. The anhydrous ammonia I mentioned is an oddball for many as most of the time you want galvanized steel structures, piping, even raceways, enclosures and hardware as well as copper wiring, but anhydrous ammonia attacks all those items and plain mild steel, black pipe, non zinc coated hardware lasts longer in that environment. Paint becomes necessary to reduce rust corrosion. Copper doesn't hold out in that environment either and even if you use well sealed enclosures and raceways it still finds a way in.

Silver, gold are conductors that can hold up in many more places - but of course are expensive.