According to Mr. Bill :
Chris,

Thanks for the help. Now for 2 stupid questions:

1) Am I correct in assuming that 3 insulated conductors (black, black
& light gray) plus bare ground is a 4 wire cable?

2) The 2 black conductors are the hot leads and the light gray is the
neutral for the 240/120, right?

The answers to both questions are "yes" - _if_ the installer complied
with code. The probability is very high that they did, but it wouldn't
hurt to visually check the panel end of the circuit. The two black wires
should connect to a pair of breakers[+]. The grey wire should be bolted onto
a terminal block with other grey or white wires. The bare wire should
similarly be bolted onto a terminal block with other bare wires.

The "block" shouldn't really be common to both bare and white wires,
but often is - no big deal in a main panel. In a main panel, the
"two blocks" are connected together anyway.

You can test it with a voltmeter too, but visual inspection is probably
more useful in this context. The cable should be easy to identify -
it will be larger than any other cable in the panel (except for the
main feed or possibly a subpanel or an appliance that draws even
more power than the stove - like an electric forced-air furnace
or heat pump with electric heater strips).

[+] the breakers should be tiebarred together.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.