Field Assembled extension Cords.

[Bill_From_GA]

Does 240.5(B)(4) indicate that field assembled extension cords can only be placed on 20 amp circuits?

 

[eric9822]

The way I read it:

Field assembled extensions cords can be supplied by a branch circuit that has a maximum 20 amp OCPD if the conductors are 16AWG or larger. Nothing says the the circuits OCPD cannot be lower.

 

[chris kennedy]

Here is the NECHB commentary following 240.5(B)(4).

Field-assembled extension cords are permitted, provided the conductors are 16 AWG or larger and the overcurrent protection for the branch circuit to which the cord is connected does not exceed 20 amperes. The cord and the cord caps and connectors used for this type of assembly are required to be listed.

Is this a 590 install?

 

[Bill_From_GA]

So I can't build a 50 amp extension cord myself. I must purchase a factory made one?

 

[Bill_From_GA]

In this case, it feeds a 50 amp spider box. But what about an extension cord for a welder to be used on occasion?

 

[TOOL_5150]

I have made a few 50A extension cords. What If I didnt assemble it in the field, what if I assembeled it in my garage?

~Matt

 

[zbang]

Not so fast . Section 240.5 tells us to use either (A) OR (B) to determine OCP for an extension cord. Section (A) tells us that we need to use tables 400.5(A/B). Under specific circumstances section (B) allows smaller gauges to be used that the 400 tables would allow, and (B)(4) allows the use 16g and 14g on a 20a OCPD for a field assembled cord set.

So I can field assemble a 200a extension cord set provided that all of the components are rated for 200a and the usage.

 

[Bill_From_GA]

Excellent and Thanks much. Does the usage of cord for extension cords meet the uses permitted by 400.7?