What our experts say …
WITH THE RANGE OF OPTIONS AVAILABLE and its ease of installation, this Pyronix sounder will no doubt rapidly gain the status of ‘belle’ in the eye of installers – even if it is a little rotund to conform to the dictionary definition!
The Belle has a modern slimline enclosure and is designed to use the exposed parts of both lid and base as the strobe lens for maximum light output.
Sound output from twin piezo sounders in SAB mode is high at 118 dBA at 1m. This is essential in a domestic bells-only situation where the neighbours’ ears are insulated by double glazed doors and windows.
The internal components are all placed well away from the outer edges of the enclosure to improve resistance to vandalism. This can be further enhanced by the addition of a 1.5mm thick optional metal shroud which covers all the internal components, including the twin piezo sounders, strobe flash tube, battery and tamper switch.
The Belle can be set to SCB mode. The sounders and strobe are then powered from the 7.2 volt nicad back-up battery. Under these conditions, the sound output is reduced to 108 dBA at 1m and the flash rate from 120 to 30 per minute. This mode can be used to avoid overloading the control panel in multi-sounder installations.
Three-way tamper protection is provided by a front and rear operated switch and power cut-off relay contacts. The loss of 12 volts from the control panel operates the twin piezo sounders in the Belle, as does the opening of a tamper switch. Surprisingly, the opening of a tamper switch does not signal back to the control panel to operate the internal sounder until the back-up battery is also disconnected.
Twin alternate flashing red LEDs, visible through the lid, indicate that there is power present – either from the back-up battery, control panel or both. A fixed 15-minute cut-off timer is included to conform to the latest EU requirements.
Construction
The Belle enclosure consists simply of a moulded polycarbonate lid and base. The base is of complex design with a central box for the components and empty side compartments, which act as strobe lenses and also provide a protective cushion against physical attack. Latches and pins are included in the base moulding, so that all components can be changed without removing the base from the wall.
The latches are a little stiff and brittle; one of the PCB latches broke off when we removed the components. A longer tab on the end of the latch would have avoided this problem by allowing finger pressure to be used to release the latch rather than having to resort to a pair of pliers.
Four mounting bosses have been recessed into the base, sufficiently deep to lift the edges 3mm clear of the wall. This improves the sound output from the two rear-facing sounders. The lid fits neatly into recesses in the base and is held securely in place by a moulded hook at the top and a single screw at the bottom.
The PCB, measuring 57 x 124mm, carries the self-alarm, timing and strobe components (including the flash tube), setting links, terminal blocks and sockets for the power LEDs, sounders and tamper switch connecting plugs. The PCB quality is of a high standard.
A transparent plastic cover protects the PCB; this must be discarded when the metal shroud is used – otherwise, the lid will not fit properly.
The quality of manufacture and construction is generally good. However we found that when fitting the lid, the hook at the top had a tendency to jam under the hinge bar on the base. Despite our best efforts to avoid this occurring, the bar eventually snapped at one end. A bit more clearance under the hinge bar could possibly solve the problem.
The hinge bar is the weakest part of the base but we consider it adequate in use, since any subtle attempt to gain unauthorised access would be concentrated on the bottom screw.
Installation
The Belle has been designed for vertical mounting but could well be horizontally installed to give a more aesthetic effect on a bungalow, for example; the alternate flashing LEDs can easily be transferred to any corner to maintain a balanced effect.
Screws and plugs are provided by the manufacturer. A knock-out has been provided at the top of the base for cable entry. We prefer a hidden cable and in domestic installations, drill through the wall from behind the sounder enclosure base, aiming for the top of the wall cavity at an angle of around 45 degrees upwards, to avoid rainwater running in at the wall cavity.
A straightened wire coat-hanger, inserted in the hole from the outside is – usually – visible, and easily reached, from inside the loft space for pulling the six-cored cable out to the sounder. It can be a bit of an adventure but the neat result more than justifies the time spent.
After the base has been fixed to the wall, the lid can be parked hanging down on its own securing screw at the bottom, and the PCB cover hooked on the hinge bar at the top. The PCB cover is reasonably safe in this position but it would not need much provocation to dislodge the lid. Is it worth the risk?
Wiring is straightforward. Pyronix gives a connection chart, listing the connections for a range of control panels.
A test link is included on the PCB. During installation, when the standby battery is connected with the test link removed, the sounders will operate for five seconds only. The test link can then be replaced and the sounders are inoperative until the tamper switch is closed AND the 12 volt supply is connected in the control panel.
During maintenance visits, the test link can be similarly employed to maintain silence, after the initial burst, until the lid tamper switch is finally closed, confirmed by a short bleep from the sounders. This is a very useful feature, since the sound output is very close to the threshold of pain.
When the metal shroud is used, it is supplied along with two steel straps. The straps are used to bridge the two top base fixing screws and the two bottom ones, giving much improved base-to- wall security. The metal shroud is put in place and fixed to the wall by a 9cm screw through the base. Properly fixed, this must be one of the most secure arrangements on the market for this class of sounder.
Care must be taken to clear the sounder leads and possibly the back-up battery leads away from the sides of the base, otherwise they could easily be cut when the shroud is fixed. The bottom edges of the shroud have been cut away to avoid damaging the flashing LED leads.
If two active sounders are specified for an installation and both are required to give maximum sound output, then a separate 12v power supply will be needed for the second sounder.
Performance
The Belle was connected and checked for correct operation. The light output from the strobe flash tube is quite impressive, particularly at night when the installer’s logo is brilliantly outlined. During daylight, light output comes mainly from the lid at an adequate level. The addition of the metal shroud considerably reduces the strobe light output both by day and night.
The Installation Instructions include technical specifications, mounting instructions and connection details, all clearly written and backed up with good annotated diagrams plus a couple of important warnings to make sure that the test link is finally left in place! Two diagrams are included to show two Belles connected in a system. The paragraph heading includes “in series” – a bit of a misnomer since only the tamper circuits are in series. The sounder and strobe trigger connections are in parallel as are the 12v supply connections when one Belle is in SCB mode.
What the manufacturer says…
Since its launch, the Belle has been one of the industry’s success stories, offering value for money coupled with an innovative design. Due to popular demand Pyronix has now designed and manufactured a 1.5mm low carbon steel shroud for this twin piezo external sounder. For high-risk installations this provides a formidable deterrent. The shroud is zinc-plated with an additional passivation to provide all-weather protection against corrosion. In addition, the stringent three-way tamper action on the Belle itself (back, front and loss of power) also adds to the high security specification.
The Belle has been specifically designed to make installations easier for the engineer by making the front and PCB covers re-attachable. This allows the installer to work on the unit without having also to hold onto each protective casing or having to make successive trips up and down the ladder.
To make life even easier the PCB, battery and speaker covers are all released by a clip mechanism saving time and again avoiding handling of tricky screws. In addition, a template is printed on the rear of the packaging to make wall fixing easier than using the back itself. The ease of installation has also been considered with the steel shroud which is assembled by means of a single screw, which passes through the shroud and base to screw directly into the wall. Two braces under the wall fixing screws add further stability and protection.
The Belle has a panoramic strobe effect which illuminates the full bellbox and the twin piezo sounder has an output of 118dBa at one metre. The Belle has two flashing comfort LEDs which can be mounted horizontally or vertically as can the unit itself. The Belle has a selectable SAB/SCB mode enabling more than one sounder to be fitted to a system.
A free printing service is available on the generously sized 330 x 165mm lid.
Overall assessment
The Belle is a very neat and attractive external sounder and strobe unit. The sound output of 118 dBA is obtained from two rear-facing piezo sounders when in SAB mode. The design of the enclosure is such that maximum light output is obtained from a single strobe flash tube and is effective even during daylight.
Resistance to physical attack is high, with all the components sited away from the edges of the base. This can be further enhanced by the addition of an optional metal shroud.
It has been designed for easy installation and maintenance, with all components easily replaced. The test link feature should appeal to installers. Finally, the Belle is sensibly priced, representing good value for money.
