Aiphone NIM Series Master Stations with Handset

Two sizes cover it: the NIM 20-Call handles up to 20 stations and the 40-Call handles up to 40. That count is the total across door stations, sub stations, ceiling speakers, and wall jacks combined, not 20 of each. Pick the size by adding up every point you intend to hang on the system, then leave headroom for the openings and rooms you expect to add later, because moving from 20 to 40 means swapping the master station itself.

48V DC, supplied by the Aiphone IS-PU-UL power supply. The master station does not run on line voltage on its own, so the power supply is a separate item you have to order with it. Keep the run from the power supply to the master station within 33 feet at 18 AWG.

Up to 650 feet at 18 AWG from a door station or sub station back to the master. That is the number that decides whether a far wing or a detached gate entry can be served from one master, and it is measured as actual cable length, not straight-line distance. The power supply run is much shorter at 33 feet, so plan on locating the IS-PU-UL close to the master station and letting the station runs do the distance.

Three conductor with an overall shield, and Aiphone specifies its own #821803 cable for it. Same cable type for every leg going back to the master station, whether it is a door station, a sub station, a ceiling speaker, or a wall jack. This is not a system you can pull with spare Cat5 or unshielded bell wire and expect clean audio.

Three things beyond the master itself. The IS-PU-UL power supply, because the master needs 48V DC and does not include it. Aiphone #821803 three conductor shielded cable for every run. And the field stations, which can be door stations, sub stations, ceiling speakers, or wall jacks in any mix up to your 20 or 40 count. Size the master to the total point count before you buy, since the capacity is fixed by which unit you pick.

All three. The master station does Selective Call to one station, Group Call to a defined set, and All Call to everything on the system. That is what makes it work for a floor where a front desk needs to reach one resident room directly and still be able to announce to the whole wing without walking anywhere.

It has a handset, and you can work either way. Lift the handset for a private conversation the room does not overhear, or use push-to-talk (simplex) at the station itself. Handset mode is VOX, so the audio switches on voice rather than needing a button held. In a nurse station, front desk, or leasing office where residents and visitors are standing at the counter, the handset is the reason to choose this over a speaker-only master.

Yes, it is a commercial-duty unit. The front panel is fire resistant ABS plastic over an SPCC steel chassis, which is what you want on a desk or wall that gets handled every shift in a healthcare, school, or multi-family setting rather than a residential-grade plastic housing.

Yes, the master station has volume controls on board. Useful where one master serves both a quiet overnight nurse station and a busy daytime lobby, since you can pull the level down without touching the field stations.