When does a FMC 90 connector need to have an isulated throat

[conmgt]

I'm seeing these available in both insulated and non-insulated in sizes up to 4"

 

[iwire]

Never specifically code required, it is just a design decision. You can always use a bushing instead when the conductors are 4 or larger.

 

[kwired]

I don't think it ever has to have insulating throat.


Having an insulating throat may relieve the need of an additional insulating bushing when required.

 

[Strathead]

Or another possible way to answer this is, "When the electrical Specifications require it." That is usually where you will see the requirement.