Castle Logo
Privacy Policy. By using this website you are consenting to the use of cookies, please read our privacy policy for more information.

Castle Care-Tech - Manufacturers of Intruder Alarms in the UK. Ring Sales on 01344 469479 Installer and Distributor Support
Please log-in or register for access
DOWNLOADS    MANUALS    PRODUCTS    TECH SUPPORT    NEWS    CONTACT    CASTLE PROFILE    TRADE SHOWS    TESTIMONIALS    CAREERS 
Wired and Wireless alarms

EN50131 FAQs


Size 1 | Size 2 | Size 3


Category: EN50131 / PD6662

  1. What kind of PA button must I use?
  2. You should not be able to get engineer access (level 3) unless authorised by a level 2 user!
  3. Does an Internal Warning Device need a tamper switch?
  4. Does an Internal Loudspeaker need a tamper switch?
  5. Detector anti-masking does not send a fault signal to the ARC!
  6. Does iD comply with Grade 3 requirements?




  1. What kind of PA must I use?
    Only 2 separate buttons with synchronised push systems should be used.

    [ Top ] [ Main FAQ ]




  2. You should not be able to get engineer access (level 3) unless authorised by a level 2 user!
    BSIA Form 171 (NSI Bulletin 03/05) comments - 8.3.1.c(ii) - as follows:

    "prEN50131-1 does NOT require level 2 authorisation for level 3 access to be carried out individually every time such access is required, it may remain in force until manually removed at level 2 - eg permitting an engineer on site to have unlimited access during his visit following a single authorisation."


    The example quoted does not restrict the authorisation to a single visit - the operative term is that "it may remain in force until manually removed at level 2” - whether this be the same day or the next year…

    The Euro "G" range implementation is that the "USER MENU" (ie press D key before entering code / tag) includes an option "Allow engineer menu?" This should be set to "NO" on commissioning the system (it is impractical to set it thus as a factory default in view of the engineer's requirements prior to commissioning). The first time engineer (level 3) access is required, a user (level 2) enters this menu and selects YES. This permits engineer access until such time that a user (level 2) reverses this selection.

    The operation is available to ALL users / managers.

    This operation agrees with the industry agreed interpretation referred to above. It also complies with the more specific statement in TS50131-3:2003 (clause 8.2.1), which becomes mandatory for control equipment from 1st October 2006.

    [ Top ] [ Main FAQ ]




  3. Does an Internal Warning Device need a tamper switch?
    prEN50131-1:2004 Table 12 identifies the system components that must be fitted with tamper detection. This shows that it is MANDATORY for WD at all grades.

    Table 13 identifies that the only means of detection that is mandatory is “opening by normal means.”

    The final paragraph of PD6662:2004 C.3.1 identifies that EXTERNAL audible alarms must be fitted with means of detecting removal from mounting.

    Other than this, there is no differentiation between Internal and External WDs, or between self-powered and remotely powered WDs.

    There are also recommendations within TS50131-7 for tamper PROTECTION of connections to WDs. These relate solely to physical protection – not to tamper detection.

    [ Top ] [ Main FAQ ]




  4. Does an Internal Loudspeaker need a tamper switch?
    A much more interesting question – which basically boils down to two sub-questions!

    1. Is the loudspeaker a Warning Device?
    If so then it must be tampered, as above.

    2. Is the loudspeaker an audible indicator of alarm events?
    If so, there is no stated requirement for an “indicator” (which may be audible or visual) to be fitted with tamper detection. There is also another factor which is sometimes raised in this connection:

    3. Does the loudspeaker also generate entry and exit tones?
    These are audible indications, for which there is no stated tamper detection requirement. As to some degree these are system specification issues, we will leave it you to draw your conclusions on a site by site basis ….

    [ Top ] [ Main FAQ ]




  5. Detector anti-masking does not send a fault signal to the ARC.
    You may recall that this was discussed in issue 21. However, queries continue to reach us, including two reports in the past week of non-conformances being raised on systems that do not signal to the ARC as expected by the inspector (who incidentally were not in agreement with each other – one expected a fault response, the other a tamper response!!)

    To clarify (and this has been checked with NSI who are in full agreement with this summary):

    prEN50131-1:2004 clause 8.4.5, clearly states:

    Masking signals or messages shall be processed as an intruder or fault signal or messages in accordance with Table 7.


    Note that this says "intruder OR fault" - leaving a choice available, but NOT permitting a “tamper” signal to be used.

    BSIA Form 171 or - perhaps better still - the reprint of this document published by NSI (Bulletin 03/05), includes the following comment as item "e" under "Table 7:

    The table (ie table 7 of prEN50131-1:2004) does not show how a system will treat masking. Clause 8.4.5 specifies that it may be processed as a “fault” OR as an “intrusion.” It is agreed that treating masking as an intrusion achieves all required responses.

    NOTE: provision of the “masking” output when the IAS is set is NOT mandatory according to the requirements for detectors in TS50131-2-x, though is preferred by insurers.

    We have therefore followed this request of the insurers, and arranged for an "intrusion" response for masking events. In the UNSET state, it will prevent setting, in the SET state it will generate an intruder alarm - ie fully compliant with the standard.

    Additionally, when unset, the panel will generate a local "alert" condition to warn the user of the condition so that it can be dealt with in advance of actually attempting to set the system.



    [ Top ] [ Main FAQ ]




  6. Does iD comply with Grade 3 requirements?
    This is completely false. Subject of course to the detectors in use, iD systems meet ALL the requirements for grade 3 systems by a comfortable margin (though require two biscuits per detector to do so).

    In fact reference to BSIA Form 171 (NSI Bulletin 03/05) clause 8.8 spells out very clearly that grade 3 can be achieved by:

    “double pole, end of line, etc – with individual tamper – iD or similar system.”

    We understand that problems have been experienced in obtaining suitable door contacts for use with iD systems, as most grade 3 contacts have integrated resistors that make them unsuitable. Having discussed this issue with detector manufacturers, we can confirm that there ARE contacts available that are suitable for use in grade 3 iD systems.

    [ Top ] [ Main FAQ ]



Home | Top of Page



Bracknell Beeches Castle, Secure House, Braithwell Way, Hellaby, Rotherham, S66 8QY, United Kingdom
T +44(0)1344 469470 | F +44(0)1344 469489

 © 2003-2013
BSIA Click here to view our ISO 9001 Accredited certificate