I can't find anything for a RN series under Schrack or Tyco but just winging it at a glance with a 2.5 K coil, based on other Shrack Power Relays I would guess (and only a guess) the coil is 120 VAC or maybe 240 VAC. Just about all the Schrack power relay family I saw for 120 VAC colis had a coil resistance of about 2.0 K Ohms. That is why I guess 120 or 240 VAC. That was true of the RM series of power relays.