See image above for reference.

It is my understanding that whether there is conduit installed or not, that any time a 4 AWG wire or larger goes through a connector such as this there is supposed to be a plastic protective bushing installed unless the connector is designed to offer equal protection and is listed for such.

Can I get confirmation on this? I'm getting some push back saying that no bushing/protector is required.

I do not think the bonding wire for the CSST that is passing through the same opening is a problem, but if it is let me know.

Thank you in advance.