Customer sent me a photo of the
receptacle today. That helped a lot, and perhaps answered some questions from him and I! Seems like almost the exact same
spring clip as used on the classic (somewhat despised)
Union Connector 20A Flange
receptacle - only doubled up on each end of the
receptacle to retain it. And a mounting flange in a different place. But the same concept and scale.
Assuming they re-used the spring tension device from a 20A
receptacle on each end of the 60A, they possibly are using the same brass pin sockets designed for
cord mount verses flange/panel mounted receptacles. That's good, between his
stock and what I will be donating (I don't use Union these days), he will have at least sockets he can replace - short of a melt down or breakage. Assuming the
receptacle can come apart, believe it does, he has replacement sockets.
Second it explains the customer next concern - should it melt down, now it would conduct to the mounting screws of the flange mount.
That gets complex, and No! But does expose a
safety hazard expressed with customer given experience with the Union
receptacle.
Voltage spike is normally too quick to melt plastic sufficient to melt enough to
ground out. A loose set screw on the
terminal male or female of especially a 60A
plug/
connector requires both the male and female to melt in carrying the
current together to finally melt a
plug and
receptacle thru and
ground out. Hard to do before something noticed - but depends on who might note a problem. Same with resistance from a pin not spreaded in loose connection not noted by the person plugging it in, resistance at
plug will have a dim lamp. You have hopefully cable support and large wires preventing gravity allowing a short to frame, but can and appairently happens.
So mostly a systematic problem of if something melts
thru... what else caused or is a problem in relation, but otherwise, yes female receptacles do wear out. Becoming loose hopefully is an indication before melt down.
As opposed to easily pulled up Marinco/Mole/TMB, and even what is currently sold by
Union Connector = they are all
bolt on and not
spring clip.
Look at the photo and see how quickly in melting a melting of plastic can short to that
spring clip. Pull up the diagrams of any 60A
bolt on
receptacle, and not that if 1/2 the diameter of a hole is as near as you can get to a opening or
edge of a plate... a flowing with the plastic will
ground out to the plate long before it shorts to a mounting screw also bonded to the plate mounted to.
The
spring clip design of the old discontinued Union
outlet.. It will first
ground out to the
spring clip which is somewhat high resistance steel to grounding out, and potentially be a time before failure with more damage.
Beyond this, Union - while in the antique days used to be a solid non-plastic type of
connector cored out, the ones later are a more brittle cast plastic with problems in melting.
Bates normal the same concept of a hollow cast
connector which will melt down or break some - but in by far less percentage - perhaps better plastic used and better set screw to
wire concept. Don't have to re-torque the cables every year, but pin
spacing is a must in each time used with all cables.
Mole, TMB and
Bates Group 2 all use a better, but more expensive old school non-plastic design for such plugs which cost a little more.
On the cable plugs, as per old school, you have to spend a little more time, get the strip length correct and use
Friction tape for
cord grip, which if applied correct will help reduce some
bend stress at the
plug of the
wire. But the old school type plugs/receptacles/connectors seem to take heat better.
This granted they will char instead of melt.
A Nylon and Vinyl
ring terminal have the same safe maximum operating temperature. Difference between them is the nylon will char but stay in place for the most part in becoming brittle. The Vinyl
insulation will just melt away in no protection left.
Such plugs have that option, and I buy the above three brands of solid 60a gear. The
Bates is fine in perhaps 1:100 melt downs, but in years ago having the same melting
thru the plastic concerns as my customer, I went with the solid stuff. Never went back.
