Edition 58 July 2012

Sigma CP Zone Disablement "Fire check" facility



As part of our continuous improvement and following feedback from our customers, a new feature has been added to the Sigma CP range of conventional fire control panels. This feature "checks" the state of a disabled detection zone and warns the user if the zone will give a fire condition, before it is enabled.

Conventional control panels require the detection devices to make the decision whether there is a fire. In the quiescent condition, the detection devices draw a very low current from the detection zone (typically less than 100uA per detector). In a fire condition the current increases to tens of milliamps, which the panel detects and indicates as a fire in that zone. The detection device in fire latches in the higher current condition and illuminates its local indicator, so it is easily identified as the source of the fire event.

To reset the detection device, the power must be temporarily removed from the detector to clear the latched state. This is performed by the Sigma CP panel when the front panel "Reset" is pressed.

When the zone is disabled on the Sigma CP series panels, the zone power is still applied but any fire or fault conditions are inhibited. This means that potentially a detection device could be latched in a fire condition and would result in a fire event on the Sigma CP panel when the zone is enabled.

Sigma CP (K and T variant) panels produced from July 2012 have firmware V214 installed and include the zone check feature.

Using the disablement 'd1.' to 'd8.' menu options to view disabled zones, if the zone number is flashing there is a detection device or call point in fire in that zone.

When the zone number flashes, press the "Reset" button on the panel fascia to reset the detection devices and ensure that the zone number stops flashing before enabling the zone.

The Sigma CP Operation & Maintenance Manual (Man-1078 section 16.10.1) and User manual (Man-1082) have been updated with this revised operation and may be downloaded using the links below.

Sigma CP Operation and Maintenance Manual

Sigma CP User Manual



Power Supply Battery Disconnect Disablement Facility



The Kentec K25000 series 2.5A and 5.25A boxed power supplies are designed and certified by BSI to meet the requirements of EN54-4 and are ideally suited to fire alarm applications.

EN54-4 requires that the power supply has two sources of power, a main power source and a standby power source. The K25000 series power supplies utilise the mains supply as their main power source and sealed lead acid batteries to provide the standby power source.

In accordance with EN54-4 requirements, the K25000 series power supplies report a fault within 15 minutes of a loss of the standby power source. This is shown as a “battery disconnected” indication.

Whilst the K25000 series power supplies are primarily used in fire alarm systems, they can also be used as a general power source in other applications where the standby power source might not be required. In such cases, it is undesirable to report a fault whilst the battery is not fitted.

We have introduced a facility to allow the battery disconnected fault to be suppressed, by switching SW1-1 on the power supply to the “On” position.

K25000 series power supplies and S406 / S407 power supplies produced from the middle of June 2012 have this facility included.

Note: In order to meet the requirements of EN54-4, switch SW1-1 must be in the “Off” position.
Details of this new facility are included in section 3.4.7 of the K25000 series manual, which may be downloaded using the link below

K25000 Series Power Supply Installation, Commissioning and Operation Manual 


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