Edition 4


Syncro with Access Key Option - Approved

The BSI EN54 approved range of Syncro control panels have been increased to include models with a front panel 'Enable Controls' key switch option.

Operation of this key switch will put the panel into Access Level 2 without the need for entering the Access Level 2 passcode, as required on existing models. When enabled, the user can navigate the Access Level 2 menu options and all front panel controls are active for the duration that the key switch is operated.

This 'Enable Controls' key switch is wired into the two position terminal block, J11 located at the lower edge of the Syncro display card. This terminal block is labelled 'Enable Control' and is adjacent to the PC configuration transfer port.

Engineers Tip
All Syncro panels can be put into Access Level 2 by means of a 4-digit passcode. However this will "time out" after 120 seconds if the panel is in a quiescent condition or 25 seconds if any events are active on the system.

The facility to leave the system in Access Level 2 is very useful during the commissioning process, as it avoids having to enter the passcode to reset the system between tests. This is particularly relevant if the Syncro system has disablements or faults present, as the 25-second time out period would be applicable.

Any Syncro panel fitted with display card hardware issue 07 (or later) has the two way terminal J11 located adjacent to the PC port. Temporarily linking these terminals during the commissioning process will keep the panel in Access Level 2 and ensure that the system can be quickly reset between tests. This will help to reduce the commissioning time and avoid the repetitive task of entering the Access Level 2 passcode.

Important - to comply with the Access Level requirements of EN54-2, any temporary link used to enable the controls must be removed after commissioning is completed.


Kitemarked Syncro panels - spares part numbers

When ordering spare parts or warranty replacements for the Syncro panels, it is essential that the correct part reference is used to avoid possible compatibility issues. This is particularly important when the Syncro panels are networked.

Syncro Display Card
The BSI Kitemarked Syncro panel display card is Kentec part number S550EN. This display card will be installed with the correct firmware and hardware facilities to meet the EN54-2 certification requirements.

The display card part reference for older 'non-approved' panels is S550. This display card is compatible with all panels with firmware versions up to the current V4.4.

Syncro Power Supply
The S400 power supply used on older Syncro panels is now superseded by the approved power supply, part reference ENS400.
The ENS400 power supply is compatible with all Syncro panels and will be supplied if an S400 power supply is ordered.

Other parts
All other parts in both the original Syncro and the BSI Kitemarked Syncro panels use the same part references. This includes the main Loop Controller board (S551A or H), Loop Extender Board (S552A or H), Zone LED board (S553 - 16 zones, S554 - 48 zones) and Network Card (S555).

Bar code labels are provided on many circuit boards. These labels include the part reference of the circuit board, followed by the six digit production batch reference and two or three digit batch component reference.
Wherever possible, the bar code label details should be quoted whenever ordering spares or warranty replacements.


LCMU and zone resistance

The Line Continuity Monitor Unit (LCMU) is designed to satisfy a requirement first introduced in the 1988 amendment of BS5839 part 1 and currently detailed in clause 12.2.2.f. of the current (2002) edition of BS5839 part 1.
The requirement of this clause is to ensure that all Call Points should continue to work when any detection device is removed from the zone.

The technique employed is that an active circuit in the LCMU sends a small signal to the panel, which is suppressed by the 47uF capacitor fitted internally in the Kentec panel.
When a detection device is removed, the Schottky diode in the detection device base unit blocks the path between the LCMU and the panel. Subsequently, the LCMU identifies that it can no longer "see" the panel capacitor and removes the end of line resistor, resulting in a zone fault at the control panel.

With the detection device removed, the diode provides a signal path for subsequent detectors and Call Points, so the requirement of the clause are met.

LCMU application restrictions
There are some restrictions that should be considered when using LCMU devices -

1) The number of detection devices installed on the zone should be less than 20.
As the call points must continue to work with all detection devices removed, the voltage drop across all Schottky diodes must be considered. A 4 volt maximum permissible drop is considered acceptable.

2) The zone resistance of all cable and connections in the zone must be less than 30 ohms.
The effect of zone resistance is significant on the small signal created by the LCMU. High zone cable and contact resistance's will prevent the LCMU from detecting the panel zone capacitor.
The zone resistance should be measured by removing the zone cables at the panel, then a short circuit applied between the zone cables at the LCMU. The cable & contact resistance is measured between the zone cables at the panel. Typical zone resistance should be less than 10 ohms.

3) The current available for detection devices is slightly reduced when using LCMU.
If there is any doubt that the quiescent zone current has been exceeded, then this can be verified by connecting the LCMU at the panel terminals with no cables connected. Prove that the zone is fault free, then connect the zone cables back into the panel - if the zone goes to a fault condition then the detection devices are exceeding the zone current available.

If detection zones fitted with LCMU devices are reporting intermittent zone faults, then the above points should be tested and verified before replacing the LCMU devices.

A copy of the LCMU datasheet may be downloaded using the link below.

LCMU datasheet

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Kentec Electronics Ltd.
Tel: +44 (0)1322 222121 Fax: +44(0)1322 291794