Appareillage - Can I use both 24V DC and 24V~ with multiple, potential-free 24V push buttons?

Yes, The push buttons on the printed circuit board of these products switch a maximum of 24V DC or 24V~. A lower voltage is switched without any problems.

The LEDs however, must be exactly 24V DC or 24V~ (non-polarized).

For multiple, potential-free 24V push buttons, use 24V~. This voltage also applies to push buttons, LEDs, dimmers and remote switches (teleruptors).