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Liquidtight flexible conduit

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bigdog

Electrical
May 31, 2001
21
Can anyone tell (per NFPA) what is the maxium run length for liguidtight flexible nnmetallic conduit.
 
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Here it is as per the Ontario Electrical Safety Code - 2003'

Rule 12-1302(2)

Runs of not more than 1.5 m of 3/8 (12) trade size liquid-tight flexible conduit shall be permitted for the connection of equipment.

Intent for Rule 12-1302(2). Since the 3/8 trade size conduit is not recognized as a general-purpose conduit raceway method, we intend that it be restricted in use to runs of not more than 1.5 m for the connection of electrical equipment.

 
Per NEC, I'm not aware of a maximum length. However, if an equipment bonding jumper is required and routed on the outside of the flex, the length of the bonding jumper cannot exceed 6 feet. This situation is typically encountered when a rigid steel conduit system is used as a grounding conductor (the el cheapo) and the flex is used for final connection to a motor. If you run a separate grounding conductor all the way back, this removes this length restriction, I believe.
 
per 2002 NEC 356.12(3): Uses not permitted, lengths longer than 1.8m (6 ft) except as permitted in 356.100(5) or where longer length is approved as essential for a required degree of flexibility.

 
except as permitted in 356.100(5)

That should have been 356.10(5)which refers to support 356.30 : every 900mm (3ft) and within 300mm (12") on every box,fitting,etc.
 
Crowbar1 is right - I missed the "nnmetallic" in the original question. My answer was for metallic flex.

Sorry for the confusion.

Dave
 
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