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50W 24V Amplifier


The Pertronic 50W Amplifier (EVAC50W24V-A) is an evacuation amplifier with integral evacuation tone and message generator with fault detection. It is designed for use in emergency warning systems with supervised 100V-Line audio distribution. The amplifier delivers up to 50 Watts of audio power to the 100V-Line.

The EVAC50W24V-A is capable of generating up to three pre-configured tones. An optional pre-amplifier provides local microphone and remote audio inputs.

Each of the amplifier’s three tones can be selected from 47 available options. The factory default tones are: An ISO 8201-compliant Evacuation tone (with verbal message); an Alert tone as specified in AS 2220 (with verbal message); and a Simulated Bell tone. The third tone provides for non-emergency applications. For example, in a school, the third tone may signal start and finish times for classes.

There are three methods of controlling tone output from the amplifier:

I. The external RS-485 bus from any Pertronic analogue addressable fire alarm panel activates any one of the three pre-configured tones

II. Switch or relay contacts connected to the amplifier’s TONE CONTROL inputs are able to activate any one of the three pre-configured tones

III. A positive dc voltage applied to the amplifier’s BELL input activates one selected tone

An optional microphone pre-amplifier provides a local microphone input (MIC) and press to talk (PTT) control. The PTT may be configured to silence the integral tone generator. Alternatively, the tone generator may be configured to over-ride the MIC and PTT inputs. The pre-amplifier also has a line level input for connecting an external audio source.

When not broadcasting audio, the amplifier continuously checks for faults on the 100 Vrms line by driving a small DC current through the output wiring, which must be correctly terminated with an end of line resistor. It is important to note that every speaker connected to the supervised 100 V-Line must incorporate a DC-blocking capacitor.


  • Default ‘Alert’ and ‘Evacuation’ tones with verbal messages as in AS2220 and ISO8201 (T3)
  • Each of the amplifier’s 3 tones may be chosen from 47 available options, configurable using on-board rotary and DIP switches
  • Verbal message duration: up to 20 seconds
  • Delivers up to 50 W to connected speakers
  • Optional pre-amplifier suitable for public address microphone or fire microphone
  • Operates from 24 Volt (nominal) DC power
  • Controllable by panel RS485 bus, TONE CONTROL inputs, or BELL input
  • Overload and short-circuit output protection
  • Fault LED displays a pattern of short and long flashes to identify any faults that have been detected
  • Supervisory system operates when not broadcasting audio and can detect:
    • Short and open-circuits on the 100V-Line
    • Power supply faults
    • Overload conditions
    • Low power output
    • RS-485 communication faults
    • Missing pre-amp (if appropriate) Custom tones and/or messages available on special order


Tone 01

AS2220 Evac Tone with Evac Message

Tone 26

1.4 kHz - 1.6kHz 2Hz

Tone 02

AS2220 Evac Tone

Tone 27

660Hz - continuous

Tone 03

Alert Tone with Alert Message

Tone 28

544Hz / 440 Hz - alternating

Tone 04

Alert Tone

Tone 29

544 @ 0.875 s - intermittent

Tone 05

T3 Cadence with Evac Message 

Tone 30

800Hz @ 2 Hz - intermittent

Tone 06

T3 Cadence 

Tone 31

800 / 1000Hz @ 25 Hz - sweeping

Tone 07

Simulated Bell Tone 

Tone 32

2400 / 2900 @ 25 Hz - sweeping

Tone 08

PA400 Tone 

Tone 33

554 Hz - continuous

Tone 09

Claxon (Star Trek)

Tone 34

440 Hz - continuous

Tone 10

400-700 Hz - 1.5 sec whoop 

Tone 35

800 / 100 Hz @ 7 Hz- sweeping

Tone 11

800/100 Hz @ 1 Hz sweeping

Tone 36

660 / 1200 Hz @ 1.5 second sweep

Tone 12

400/450Hz @ 0.5 Hz tone

Tone 37

Two-Tone Chime 1000/650 Hz

Tone 13

2400/2900Hz 7 Hz - sweeping

Tone 38

745Hz @ 1Hz - intermittent

Tone 14

2400/2900Hz 1 Hz - sweeping

Tone 39

1000 & 2000Hz @ 0.5s alternating

Tone 15

500/1200Hz @ 1 Hz - sweeping

Tone 40

1000 Hz continuous - PEEER Toxix Gas

Tone 16

1200/500Hz @ 1 Hz - DIN/PFEER

Tone 41

2000 Hz - continuous

Tone 17

2400/2900Hz @ 2 Hz alternating

Tone 42

1200 Hz - continuous

Tone 18

1000 Hz @ 1Hz - intermittent

Tone 43

800 Hz/1000 Hz @ 4 Hz alternating

Tone 19

800/1000Hz @ 0.875 Hz - alternating

Tone 44

RH3 Tone 500 Hz –1400 Hz @ 5 Hz repetition

Tone 20

2400 Hz @ 1 Hz intermittent

Tone 45

'SOS' in Morse code

Tone 21

800Hz 0.25 s on, 1s off - intermittent

Tone 46

300 Hz - 1400 Hz - 300 Hz Sweep

Tone 22

800Hz - continuous

Tone 47

3480 Hz 130 ms on/off

Tone 23

660Hz 150mS on, 150mS off - intermittent



Tone 24

544 (100mS) / 440 Hz(400mS) - NF S 32-001



Tone 25

660 Hz 1.8s on, 1.8s off - intermittent







Ordering Information

Product Code



EVAC Amplifier, 50W 24V, with Integral Tone and Evacuation Message


Technical Manual

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