I'm going to be the village asshole and state that I don't trust any connection which relies on the strength of plastic to maintain contact pressure necessary to make a high-current connection. I see these as barely better than Scotch-Loks and back-stab electrical outlets.
Particularly with solid-core wire, part of making a good connection is the covalent area created by flattening/deformation of the wire by screwing down under a screw or twisting and nutting. IMO, you simply cannot apply adequate force to make that deformation happen pressing against plastic, no matter how much mechanical leverage your cam-dingus makes.
You are correct. Put 120A by a 221-402 for ~30 minutes. That will remove the plastic case. But only do it in a fireproof environment wearing appropriate breath protection. If you don't have something like this: Don't do it.
However, after removal of the plastics, the electric connection will still be perfectly intact without loss of contact pressure.
It's a brass spring pressing the wire(s) down on a copper bus bar, all of that covered by an anti-corrosion elloy.
Same for all the CEE7-Outlets with spring terminals I know. The plastics is only used for release, never for the actual contact.
...unless you look at many 50c terminals from China. They quite often use metal spring on a plastic "busbar", especially in cheap LED Lights. Only the spring acts as busbar then. Pure shit.
I stand corrected.EDIT:
Except that if it's using spring pressure, it is not enough to create the deliberate deformation of the wire I was talking aboot. You have no way of knowing if there is plastic in some part of the cam mechanism that can melt/deform away, decreasing that pressure unless you take one of every package you buy apart to make sure. You also have no way of knowing if the person doing any particular job bought decent or shite ones.
And yet the same connection under a properly-tightened screw terminal/barrier strip will rise by a few 10s of degrees. Still seems like
inadequate contact pressure to me, just like a back-stab electrical outlet. And if it gets that hot, then the wire-cladding will be similarly
...
Welcome to the wire-nuttery, BTW... you'll fit right in. The neverending taco truck is in the corner; their BEC breakfast tacos are epic. bean's been finding new ways to beat Frustion360 into submission, so new widgetry should be soon forthcoming;
Papa Smurf is balls-deep in his type 547, and swears they're doing just fine, so...
bd139 is back on the wagon so expect some bd-BOOM!!! moments any time now.
If you see Saskia pulling something from a gunny sack, look out; it's probably the liver of a real estate agent who failed her.
The crusty old Aardvark in the corner is mostly harmless, unless you see him tinkering with his GPSDO. Somebody needs to remind him that
"Time is an illusion; lunchtime doubly so..." and since you're the new guy, looks like you're elected.
Oh, and the pervy little dragon fancier schtick is mine; but I do offer a workshop on Discord almost every Saturday afternoon.
mnem