Amplifier - 831

General Information

The 831 is used with the 801, 870W and 902 series handsets, primarily for use in apartment house intercoms, but can be used for small home and office intercoms.
The Alpha Communications/Elvox model 831 amplifier/power supplies are used with the 801, 870W and 902 series 5-wire apartment handset stations to provide intercom amplification and power to operate the electric door opener(s) etc. The 831 operates on 120VAC primary power, and requires no additional transformer(s). The 831 amplifier/power supplies are designed to easily surface mount right onto the finished wall by means of customer supplied screws. Connections are positive screw terminal type.

Easily Installs Right on Finished Wall Surface or in Customer Supplied HousingClear Voice FidelityExternal Entry Station Adjustable Volume ControlConvenient Screw Terminal Connections


Dimensions: Height: 4.55″ (116mm)
Width: 5.55″ (141mm)
Depth: 2.60″ (67mm) from mounting surface
Connections: Screw Terminal Connectors.Architects’ and Engineers’ Specifications

The power supply/amplifier shall be Alpha Communications/Elvox
model 831, or approved equal. Amplifier shall operate from a 120VAC primary
power. All wiring to power supply/amplifier shall be low-voltage Class II wiring,
installed as per all federal, state, and local electrical codes. Power supply/
amplifier shall surface mount right to the finished wall and shall be installed
in a suitable environment that is free from excessive dirt, dust, temperature,
humidity, grease and water. Power supply/amplifier shall provide the intercom
amplification and signaling power for proper system operation. For most secure
installation, power supply should be installed into a lockable equipment
cabinet/housing. Power supply/amplifier shall be installed a safe distance
from any source of electrical interference.
Optional Components

DO-001 (or equivalent) 16VAC Door Release.
839/002 Dual Entrance Audio Adaptor. Used when switching audio (intercom) and door release
between two (2) entrance stations. Used in addition to 831 system amplifier.
839/003 Three Entrance Audio Adaptor. Used when switching audio (intercom) and door
release between three (3) entrance stations. Used in addition to 831 system amplifier.
R1 Pulsating Buzzer Adaptor. Used when you have individual apartment door pushbuttons
that need to signal (buzz) the apartment handsets. Converts steady buzzer to pulsating buzzer.
PK407A Specialty Relay Adaptor. Used when connecting a door opener other than a 16VAC
type to system. One (1) required for each building entry door opener.

Wiring Requirements

Apartment riser wiring shall be 4-common #22AWG and 1 selective wire #22AWG, for each
handset station connected to the riser cable. Add 1-#22AWG common wire if there are optional
apartment pushbuttons which will also have to signal apartment handset, when visitor is at
apartment door (and when using optional R1 pulsating buzzer adaptor). See 831 system wiring
diagram for more complete wiring information.

Amplifier – 831
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