NuTone NM100 Series Intercom Retrofit System — Installation Manual

Overview

The NuTone NM100 is a whole-house music/communications retrofit system designed to replace an existing intercom system using the home's existing intercom wiring (3 or 4 conductor). It supports remote stations, door stations, an optional NC300 6-disc CD changer, and external music sources.

Model: NM100WH. NuTone Technical Support: 1-888-336-6151.

Important Safety Instructions

• Must be installed by a qualified dealer or installer, conforming to all local building and electrical codes.
• For continued fire protection, replace the power switch module fuse only with the same type: 3 Amp, 250 Volt.
• Do not attempt to service the NM100 yourself — opening or removing covers exposes dangerous voltage. Refer all servicing to qualified personnel.
• Locate the system away from heat sources; do not install in an outside wall or expose to moisture (voids warranty).
• Do not place the master or remote stations in a wall cavity with other electrical wiring.
• Install the NM100 system only after wall covering material has been applied.
• Outdoor remote station speakers are weather-resistant but NOT waterproof — avoid continuous direct water exposure.
• Do not connect a remote or door station wire if you're unsure of its termination point — this can damage the system.
• Do not splice or staple cables (staples cause shorts; splices defeat signal isolation).
• Do not connect unauthorized devices. Authorized: line-level audio components, NC300 6-disc player.
• Un-terminated future-speaker cables must not be connected to the NM100 master — this can cause electrical feedback that damages the master station.
• Do not over-tighten remote/master station screws — plastic face panels may crack or strip.
• Use only NuTone-certified replacement parts, installed by a NuTone dealer/installer.
• Clean the master and remote stations with a damp cloth only — no liquid or aerosol cleaners.

Wiring Cautions

• A qualified electrician must run a dedicated 120V AC line to the NM100 retrofit transformers (required to avoid interference from looped power circuits; ground is necessary for proper radio reception).
• Individual wire runs: max 350 feet from any single remote station to the master; max 1000 total feet for the entire system.
• Label all wiring runs — incorrect connections can damage the system.
• Run a single "home run" cable from the master to each remote/door station — do not loop cable from one remote station to another.
• Do not run electrical wires through rough-ins; if 120VAC wiring is found in a rough-in during retrofit, have a qualified electrician reroute it.
• Keep cables at least 18 inches from fluorescent fixtures, dimmer controls, and other wiring (AC wiring, security cable, cordless phones) to avoid hum/buzzing.
• Keep cables away from HVAC ducts, metal construction plates, and sharp edges.

Remote Station Rough-In Placement Cautions

• Do not install in return air ducts, exterior walls, or saunas.
• Do not install in stud cavities with other wiring/appliances, or within 18" of dimmers, fluorescent fixtures, security wiring, cordless phones, or other control wiring.
• Do not install within 10 feet of, or facing, or in the same stud cavity as, other remote stations or the master — causes acoustic feedback.
• Ensure all rough-ins are level and correctly oriented.

Installation Overview

The NM100 retrofit installation follows these steps: develop the job estimate → remove the old intercom system → install the NWH300 or NWH300C rough-in → replace the remote stations (leave existing rough-ins in place) → install the optional NC300 player → install the NM100 master and make all remote station connections → test the system.

Required Tools

#2 Phillips screwdriver, wire stripper/cutter, tape measure, level, tin snips, digital multimeter, small precision screwdriver, power drill with 1" auger, small crowbar, large flat-head screwdriver, rubber mallet, extension cord, wood chisel, dry wall saw.

Job Estimate — On-Site Checklist

• Determine the model number and manufacturer of the existing intercom system.
• Count remote stations and door stations; determine surface vs. flush mount.
• Remove the master from the wall and check for non-standard conditions: electrical or telephone wires running through the rough-in, non-16" stud spacing, wire type used (NuTone, M&S, or telephone wire), presence of a remote transformer or remote door chime.

Removing the Old System

Turn off power at the intercom location first. Remove screws, carefully label each wire with its room location before disconnecting, then remove the existing wall housing and transformers. If the old system wasn't working, check each remote-to-master wire run for shorts before installing the NM100. Replace NuTone 3-wire runs with NuTone IWA3 cable; replace NuTone/M&S 4-wire runs with NuTone NW4S cable. Have a qualified electrician reroute any 120VAC found running through the rough-in.

Installing the Rough-In

The NWH300 rough-in is used for intercom-only replacement systems; the NWH300C is used for combination systems with the NM100 master plus the optional NC300 CD player (requires a larger cutout — check the stud cavity for obstructions first). Both are designed for 16" on-center studs; position so transformers sit at the bottom. Connect the dedicated 120VAC/60Hz line with ground from the power panel per the wiring diagram — a dedicated circuit is required.

Wiring Reference Tables

Replacing the Room Stations

Leave the existing remote/door station rough-ins in place; only replace the station itself. Verify wire integrity, install the NF300RWH mounting plate/frame (level, using the appropriate screw holes), then wire the new remote station: use NRS103WH for 3-wire installs, NRS104WH for 4-wire installs, and NRS200WH for all 6-wire installs (see Appendix A for system mapping). Plastic frames are paintable — prime first, then apply standard room paint (white plastic may need two coats); paint before mounting. Label all cables at both ends — incorrect connections can damage the system.

Outdoor Remote Stations

Do not remove the existing outdoor rough-in — the retrofit system fits the existing enclosure. Outdoor stations are weather-resistant, not waterproof; avoid direct sprinkler/rain/pressure-washer exposure. Use the NF300PWH frame (UV/fade resistant) for outdoor/high-sun flush mounts, or the NRKS200PWH surface-mount box/cover (supports NPS200WH, NPS103WH, or NPS104WH outdoor stations) for patios.

Door Stations

Remove the old door station but keep the rough-in/surface box. Use the NF300DWH mounting frame (works for both NuTone and M&S door stations); connect using corresponding color wires.

Installing the NM100 Master

Ships configured for 3-wire retrofit. For a 4-wire system, change the jumper setup (pull jumpers from the 3-wire connections and reposition to the 4-wire position) BEFORE connecting any cables. Suspend the master from the rough-in hook using the support wire assembly (thick green wire) — avoid damaging the wall.

• Remote station wiring: connect each remote's Green wire (except outdoor/patio) to a numbered Green terminal — max 2 green wires per terminal. Speaker limit: 15 for 4-wire systems, 13 for 3-wire (doesn't include remote/volume controls, but does not include door stations either).
• Outdoor/patio: connect outdoor remote Green wire(s) to the Patio green terminal, Black wire(s) to the Patio black terminal — max 2 outdoor remotes on patio terminals.
• Connect Red wires together to the Red terminal, White wires together to the White terminal.
• Door stations (NW4S cable): connect red/black wires to the door station red/black terminals; insulate bare shield wire and connect to the "shield" terminal; connect orange wires to the chime module's common terminal; connect each yellow wire to its own note-selection terminal (max one yellow wire per terminal).
• Plug the chime module's modular plug into the 4-pin CHIME connector on the master.

Antenna Connection

Keep intercom cables separated from antenna leads (intercom cables can shield/degrade radio reception) and away from metal ductwork/foil-backed insulation.

• NuTone 300 Ohm twin-lead antenna: cut off any plug, strip both wire ends, connect to terminals S1 and S2 on the antenna board.
• Separate AM/FM antenna (300 Ohm FM twin lead + orange AM wire): FM twin leads → S1 and S2; AM antenna (orange wire) → S4; S3 unused; add a bare jumper wire between S3 and S4.
• Single orange wire antenna: connect to either S1 or S2 (never both — this shorts the FM signal); add a bare jumper wire between S3 and S4.

Door Release Options (dry contact, 24V/2A) — pick only one per system

• Door/gate release mechanism: run 18-gauge solid copper twisted-pair low-voltage cable from the rough-in to the release mechanism's two-wire terminals.
• Panic interface with security system: run 18-gauge solid copper twisted-pair cable from the rough-in to the security control panel; configure the panel for a normally-open dry contact panic input (have a certified security installer make the connection).

External Music Source

Choose a location for the IA30WH audio wall plate near the source device (receiver, TV, DVD player) — the run to the NM100 must not exceed 50 feet. Mount the IR30K single-gang box to a stud at standard outlet height, run the included red/black shielded audio cables from the master location to the wall plate, and connect.

Optional Accessories

• Chime module (NA3003C/NA3008C): press over the 4 plastic standoffs in the rough-in.
• NC300 CD changer: connect audio cables to the NC300's audio jacks, then connect the NA200TA transformer power cord to the CD changer. Ensure nothing (including cables) sits between the player and the back of the rough-in; mount using the NF200C/NF100C frame opening and provided screws.

Testing

Plug the NM100 power connector into the NA300TA transformer and secure the master to the rough-in with the 2 provided screws (do not over-tighten — plastic may crack). Install the speaker panel, applying pressure only at the corners. Check all functions per the Owner's Manual. If issues persist after rechecking connections, call NuTone technical support at 1-888-336-6151.

Appendix — Frame Reference

• NF100MWH — replacing a master-only system with an NM100 master
• NF100CWH — replacing a combination system with an NM100 master + NC300 CD player
• NF200CWH — replacing a master-only system with an NM100 master + NC300 CD player (requires enlarging the wall hole)
• NF300RWH — all indoor remote station replacements
• NF300PWH — outdoor/high-sun-area flush-mount remote station replacements
• NRKS200PWH — outdoor surface-mount remote station replacements
• NF300DWH — older NuTone door station replacements (not required for M&S)

Appendices A and B in the full manual map specific legacy NuTone and M&S intercom system models to the correct 3-, 4-, or 6-wire NM100 configuration (6-wire requires the NM200 master). Loop-wired existing systems can only convert to an IM5000-compatible configuration; fully home-run-wired systems can convert to an NM200 configuration. See the downloadable PDF for the full model cross-reference charts.