Cam-Lok

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Originally trademarked by Empire Products of Cincinnati (bought by Crouse-Hinds, now Cooper), the series E1016 is the industry standard for single pole high amperage connectors. E1016s are rated up to 400A. The E1015 series, rated up to 100A are often called "baby Cams." Many companies make compatible connectors. Leviton is one. The author prefers Advanced Devices CL2 series, for their ease of assembly and repair.

The National Electrical Code requires that these connectors (and indeed all single-conductor cables) be used only by a Qualified Person.

For 120/208VAC operation, the colors and uses are
Green=Ground
White=Neutral
Black=Phase A
Red=Phase B
Blue=Phase C
While they should not be made or broken live, the connectors should always be plugged in in the above order, and unplugged via the reverse.

Seldom seen in the theatre, the colors and uses for 277/480VAC are
Green=Ground
White=Neutral
Brown=Phase A
Orange=Phase B
Yellow=Phase C
While they should not be made or broken live, the connectors should always be plugged in in the above order, and unplugged via the reverse.

Per NEC definition, Cam-Loks are Single-Pole Separable Connectors, and limited only to use by a Qualified Person, per the NEC. See NEC 520.53(P).

Quite often when discussing Cam-Loks, the topic of reversing the gender of ground and/or neutral arises. For posterity:

Some history:

1. Cam-Lok E1016 connectors were first used in an entertainment application on Colortran 6 x 6kW portable dimmer packs, circa 1977. In order to attempt UL Listing, they needed non-intermateablility of hot, neutral and ground. This was at least 7 years prior to NEC recognition of single conductor feeders and single-pole separable connectors, with their associated connection-order rules. Without these NEC rules, UL made up some of their own: no intermateability of hot, neutral, ground. (Note that even today, the NEC makes no statement about non-intermateability of these specialized connectors).

2. Colortran used Empire Products E1016 males on the hots, an E1016 female on the neutral, and a female Palmgren Screw-Lok on the ground. The Palmgren Screw-Lok was a hideously expensive, long lead-time connector that used the same female neoprene housing as an E1016, but was not mateable with E1016. Another great feature: its cable boots only came in a vulcanized version, not the "Lektra-Link" style that is now standard on E1016. That meant:

--A vulcanizing press
--Vulcanizing tape
--Gooey vulcanizing lube
--At least 10 minutes curing time per connector
--No field installation or removal, unless you had a vulcanizing press in your workbox

3. Production Arts owned a bunch of those Colortran packs, and after extreme frustration with the Palmgren Screw-Lok's, we changed them out for female E1016's. Our logic: better to guarantee no intermate of hots with neutral and ground. That arrangement became our standard on touring gear, and I guess our logic caught on with some other rental companies-- but there were notable holdouts such as Vanco.