Hey guys thanks for the help on these little issues I
run into. I want to use NEC 300.3 (C)(1)
"Conductors of ac and dc circuits rated 600 volts ,nominal, or less, shall be permitted to occupy the same equipment wiring enclosure, cable, or raceway. all conductors shall have an insulation rating equal to at least the maximum circuit voltage applied to any conductor within the enclosure, cable or raceway."

The voltage is 120/240 a.c. and I want to install the start and alarm conductors in the same J-box box as the power. The alarm cable specified is rated for 300 v. dc.
300.3 (C)(1) only refers to the voltage rating so I'm thinking it's OK even though the alarm conductors are only rated for dc. Right?