Listed below are the most frequently asked questions for the NHX Series. If you are unable to find the information you are looking for please contact our Technical Support team.



How many stations can the nhx series support?
The NHX Nurse Call system supports one master station and up to 80 patient stations (NH-1SA/A or NH-2SA/A), which include the NHR-3TS addressable common area call station.

To view a list of all available models for the NHX Series click here.

Is the nhx Series compatible with other aiphone intercoms?
NHX Series stations are not compatible with other intercom stations from Aiphone, including “LEF” master stations. All compatible master and door/sub stations must contain the prefix of “NH” or “NHX”, ex. NH-1S/A, NHR-SP and NHX-50M.

What type of wire is used with the nhx Series?
The recommended wire for the NHX Series is Aiphone’s 4 Pair, 22 AWG, Shielded, Low Cap Wire, part number 862208.

nhx Series wiring distances.
The trunk line for a set of rooms may have exceeded the maximum allowable cumulative wire distance, which is 330’ with the proper wire, Aiphone 862208.

How can the NHX-50M master station accommodate up to 80 stations?
For 51-80 stations, you will need to add the NHX-30G add-on selector, which attaches to the NHX-50M master station. You will also need to add the NHR-30K add-on PC board, which installs inside the NHX-80X Central Exchange unit. This gives you access to trunk lines 6-8 in the CEU, and stations connected will ring into the add-on portion of the master station, columns 6-8.

Is the NHX Series UL 1069 listed?
Yes, the NHX Carries the UL 1069 standard for hospital signaling and nurse call equipment.

Can only call cords and corridor lights be used for the NHX Series?
No. The NHX is a microprocessor-based common bus system, and therefore needs an addressable station at each location where call cords, bathroom pull cords, and/or corridor lights will be used. Addressable stations are model NH-1SA/A, NH-2SA/A, both of which have audio communication as well.

The NHX system is wired and powered but the stations will not initialize. What could be the problem?
  • Verify all CN1 connections on room stations wire back to the NHX-CEU. This is the common trunk line that carries the audio, data, power between the NHX-80X and the patient stations. Make sure that the CN2 connections are wired to the corridor lamp and bathroom pull cord for each patient room only. If the wiring is reversed between CN1 and CN2, you will need to disconnect and rewire, as the connectors are not the same size.
  • Verify all bedside call cords are plugged in and all pull cords are in the up or standby position. If you have NH-2SA/A patient stations and only one call cord, you will need to install a dummy plug or second call cord into the other jack.

Can I add more than one NHR-SP duty station to the system?
In order to be in compliance with the UL 1069 listing, each system must have no more than one duty station.

I can hear faint DTMF tones during communication at the master station. Why is this?
  • The trunk line for a set of rooms may have exceeded the maximum allowable cumulative wire distance, which is 330’ with the proper wire, Aiphone 862208.
  • The cable used may not be the right type, and may not be twisted pair. Verify that the cable is twisted pair, solid, low capacitance with polyethylene insulation.
  • In either of the above situations, you may be able to compensate for the noise in the audio line by running a separate 2 conductor wire for the audio, then connect the brown and red wires from each station’s CN1 connector into the separate pair. This will separate the audio line from the data line, which should eliminate the noise from being heard.