Discovery Sounder VAD Base with Isolator

Product code: 45681-700APO

45681-700APO - Discovery Sounder VAD Base with Isolator
The Discovery Sounder VAD Base makes full use of the Discovery protocol. For ease of commissioning, a ‘Magnetic Wand’ can be used to test and adjust each sounder VAD locally.
Full Details
Brand Information

Discovery® is a range of high-specification, analogue addressable fire detectors and alarm devices. Discovery detectors offer effective false alarm management by a combination of EN 54 approved operating modes and sophisticated algorithms. Drift compensation further reduces the likelihood of false alarms caused by a build-up of dust in the sensing chamber. In addition to the familiar smoke and heat detectors, the Discovery range features two multisensor detectors. One is an optical/heat multisensor which can be used to protect against many types of fire risk. The other is a carbon monoxide/heat multisensor which protects against both smouldering fires and those generating heat.


The Discovery Multisensor construction is similar to that of the optical detector but uses a different lid and optical mouldings to accommodate the thermistor (heat sensor). The Discovery Optical/Heat Multisensor Detector contains an optical smoke sensor and a thermistor temperature sensor whose outputs are combined to give the final analogue value. The way in which the signals from the two sensors are combined depends on the response mode selected. The five modes provide response behaviour which incorporates pure heat detection, pure smoke detection and a combination of both. The multisensor is therefore useful over the widest range of applications. The signals from the optical smoke sensing element and the temperature sensor are independent, and represent the smoke level and the air temperature respectively in the vicinity of the detector. The detector’s micro-controller processes the two signals according to the mode selected. When the detector is operating as a multisensor the temperature signal processing extracts only rate-of-rise information for combination with the optical signal. In these modes the detector will not respond to a slow temperature increase – even if the temperature reaches a high level. A large sudden change in temperature can, however, cause an alarm without the presence of smoke, if sustained for 20 seconds.

Product Information

The Discovery Sounder VAD Base makes full use of the Discovery protocol. For ease of commissioning, a ‘Magnetic Wand’ can be used to test and adjust each sounder VAD locally.

Key Features

EN 54-23 Certified Category O VAD 0.5Hz Flash Rate (white). Volume control from the fire control panel 15 pairs of tones Built-in isolator Unique acoustic and VAD self-test EN 54-3 Certified Sounder

Search engine tags

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Warranty10 year
Selectable volume(s)
  • 60dB (A)
  • 70dB (A)
  • 74dB (A)
  • 78dB (A)
  • 82dB (A)
  • 86dB (A)
  • 90dB (A)
Protocol voltage (min)5V
Protocol voltage (max)9V
Protocol voltage5 to 9V peak to peak
Maximum power-up time<1 second
Quiescent current500μA
Quiescent current tested at24V dc
Terminal functions +R+R Remote indicator positive connection
Terminal functions -R-R Remote indicator negative connection
PolarityL1 & L2 are polarity sensitive
Humidity (min)0% RH
Humidity (max)95% RH
Humidity Noteno condensation or icing
Humidity0% to 95% (no condensation or icing)
Operating temperature (min)-20°C
Operating temperature (max)60°C
Operating temperature-20 to 60°C
IP rating ValueIP21D
  • EN 54-3
  • EN 54-17
  • EN 54-23
  • CPR
  • FG
  • LPCB
  • VdS
Product length38mm
Product diameter100mm
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