Proximity wiring for limit switches, safety relay and a contactor

[john swift]

The resistance of a 24V AC coil is too low to limit the current to a safe level when its connect to 24V DC

Connecting a DC coil to AC will reduce the current and may not pull in the contactor
and the eddy currents in the magnetic core heat the core
(usually laminated cores for AC & solid for DC)

Its a few year ago I last bought contactors from RS conponents

The klockner moeller contactors I bought had 48V dc coils ,
I clipped 2 contactors onto a mechanical interlock for 3 phase motor direction control
(to make it impossible for both contactor to make a connection )

From what I remember the coils available was
24V DC , 48V DC , 24V AC , 48V AC , 110V AC , 240V AC or 420V AC

John