supply fan motor entry hole to small for flex.

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tld38

Member
Location
Cleveland
Hi everyone! I have a question. I am feeding a supply fan for make up air for a kitchen hood. My understanding is that NEC300.22(B) requires only 4' lengths in flex in this area. The hole is too small for the 1/2'' flex connector. So I tried a 3/8''90. No go! Do they make a 1/2'' or 3/8'' fitting with a 5/16'' head to fit this hole that is not threaded? Any help is greatly appreciated!!
 

480sparky

Senior Member
Location
Iowegia
I can't imagine an electrical KO that is first, that small and second, would be threaded. Sure it's for electrical and not fire supression?
 

tld38

Member
Location
Cleveland
supply fan entry hub is 5/16th hole

supply fan entry hub is 5/16th hole

Hi again! As I stated ,the hole is not threaded. Cannot hole saw, cannot unibit, cannot punch, I,ve never seen anything like it! I,m wondering if it could be a metric fitting. There is only a 1/2'' between the hole and the motor. I had to find special right angle flag crimps. It is definately a supply fan. I,m calling a motor repair shop tommorrow to see if it may be a special fitting, and I,ll try to contact the motor manufacturer. It is really throwing me for a loop beacause if that is yhe case, doesn,t that go against NEC chapter3? I understand if it listed for the manufacturer then it may be OK.
 
This could be similar to the connection used for under counter lights. The hole for connecting the light is for 3/8 inch pipe, the light came with a reducing adapter from a ? inch female to a 3/8 inch male threads and lock nut.
 

tld38

Member
Location
Cleveland
Motor dilemma!

Motor dilemma!

I really appreciate all your comments. I just find it hard to believe that they punched the hole wrong! I did have one other option I came up with. worst case I picked up a handybox extension ring. run my feed through and blank off. Tac weld the box to the motor being that I don,t even have clearance to drill and tap. I just want to exhaust all other options first. The wierd thing is, that when I went to feed the exhaust fan ,the peckerhead was inaccesible. I could get to the hole which just happens to be a threaded 1/2'' hole but that was it. the tinners fabricate and put all the components together. real bad design! I called the guy and told him that I,m leaving everything there for them. They are going to have to take the motor off the bracket,belt and all to do the hookup. A real learning experience!
 
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