Bell box hold off

[Guest andy jinks]

Time to put the cat among the pigeons.

There seems to be some strange advice being given out on how to wire bell boxes.

The common opinion seems to be that in day mode removing the bell box cover should not sound the bell.

BS 4737 which NACOSS and SSAIB companies install to clearly says that it should.

Below is a direct quote from BS 4737 (SEE WHAT YOU THINK)

8.2.5 N4A Operation .The external audible alarm shall sound in the event of an electrical change in its connection(s) to the control equipment or if its tamper detection operates.

In these circumstances an alarm condition shall be generated at the control equipment. Otherwise the external audible alarm shall operate only when an alarm condition is received by it, or it is tested

I have spoken to a NACOSS inspector just to get a final yes or no and here goes.

Removing the bell box cover should sound the siren in all cases.

If there are companies out there that are being inspected to BS 4737 and are not receiving a deviation they should ask why.

Discussion is a beautiful thing.

[Guest Affinity]

Andy as far as I am aware all Bellboxes should have a 24 hour tamper in day mode or not and the bell should activate if the cover removed. This is part of British standards and we have been doing it since the mid 80's

Regards Linda

[Guest andy jinks]

Dave that did make me laugh.

I

[Service Engineer]

Youve totally lost me Andy (what made you laugh ?), also if you send a message to anyone then I have no way of knowing about it, yet alone stopping it.

Freedom of speech is never discouraged on this site, and I`d only ever edit a post if asked to do so by the postee, or if it contained some un-necessary bad language.

[Service Engineer]

8.2.5 N4A Operation .The external audible alarm shall sound in the event of an electrical change in its connection(s) to the control equipment or if its tamper detection operates.

In these circumstances an alarm condition shall be generated at the control equipment. Otherwise the external audible alarm shall operate only when an alarm condition is received by it, or it is tested

There is no mention in those sentences about what should occur when the panel is in engineers mode, these criteria are met in all NORMAL conditions except when in engineers mode.

The FACT is that regardless of which way the bellbox is actually wired then NONE of the above sentences actually apply when in engineer mode.

The external audible alarm shall operate only when an alarm condition is received by it, or it is tested

[Guest andy jinks]

Dave that was a bit of a misquote, you missed out the otherwise

[Service Engineer]

No one here, especially me is disputing that Andy.

Off course the bells should sound, but wired either way the end result is the same.

re:

There seems to be some strange advice being given out on how to wire bell boxes.

The common opinion seems to be that in day mode removing the bell box cover should not sound the bell.

Where is this strange advice, I dont remember telling anyone the bellbox shouldnt sound in day mode.

[Guest Adrian]

B)In day mode Yes i think it should go off

Adrian B)

[Guest andy jinks]

The chap that was having problems with the scantronic 9448 wired his bell box the way it said to in the manual, so that in day mode if the bell box cover was removed it would go off.

You said the manual was wrong and then told him to wire it in such a way that it wouldn

[Service Engineer]

Heres the origional Querie i replied to.

One final question, as I am not in good books of neighbours, will disconnecting supply and then playing around with wiring set off the external alarm?, I want to try and avoid that!!

The model is "9448+style", as I say I have installation guide and user guide but neither give anything on trouble shooting, presumably there is something else for this?

Thanks for all the help it is really appreciated.

And heres my replies.

Also your negative Hold off and tamper return are wired the wrong way round:

Tamp Out should go to TR (Tamper Return)

Supply- Should go to 0vdc

Supply+ 12V

Trigger Bell

Strobe+ 12V

Strobe- STR

Also:

1, correct (or do as Gazzerdaman suggested)

2, correct

3, I`d leave it set for 7 days.

And

The way youve wired the bellbox wont have any adverse effects on the way it works, but I see the manual as being wrong. The way the manual suggests you wire it would mean the bellbox would still sound even if you removed the lid while in engineers mode.

TR stands for Tamper Return this means the 0 volts (hold-) is returned to the control panel AFTER passing through the bellbox tamper springs or switches.

The way your manual instructs you to wire it would mean the bellbox HOLD- would be passing through the springs or switches first thus removing the hold- whenever the bellbox lid is removed.

While this isnt a bad thing its annoying if your an engineer. I like to be able to put the panel in engineer mode and know i can check out the bellbox without it blaring away at me when i remove the lid.

Gazzerdaman`s suggestion was to simply feed the bellbox directly from the backup battery to save you having to get up the ladders, all you need to do is remove the wiring from the panel, and connect supply+ to the positive terminal off the battery and the supply- to the negative terminal off the battery. This will make the bellbox still appear active if it has a flashing light and keep it silent while disconnected from your control panel.

I dont mention anywhere about the tamper being disabled in DAY mode.

And heres another querie:

I recently was asked to remove a DA abacus system connected to redcare from a old church. I did not have the engineers code or know how to use the panal, so when i got there i found the main unit, poped the lid which triggered tamper, which i silenced with the user code. After i found the hold offs for bellbox i wired them to the backup batt and powered down, and removed the system.

I got up to the bell box and removed the main screw holding the lid in place, this made the siren go off. I was under the assumption that as long as the hold off was in place adn the neg- trig was not hooked up, the siren would not fuction?. Anyway i silenced it up in the end and removed( slightly deafer than before ) it but i was thinking how do you go about putting the boxes up and servicing them without deffening yourselfs? I Had a look at the box when it was down and the hold off was wired though the tamper microswitch so no wonder it went off. So what do you do in this situation, is it just a case of grim and bear it till the lid is nback on ? or invest in a good set of ear defenders?

When ive wired systems before ( not on a professional level ) i connected the lids tamper switch though the tamper return to the panal, so enginnering mode enables me open the bellbox.

And heres the reply which i think your reffering too:

Thats the way it should be done.

When some idiot wires it up the other way, then yeah its a case of grin and bear it, or temporarily defeat it by holding down the tamper switch to re-connect the hold off or removing a bellbox battery lead for a while.

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I work for an SSAIB approved company (Same Standards apply) Perhaps its just the preferance of the company you work for, but it doesnt state in the standards that thats the way it should be done, if it does i`d like to see where ?.

Im sure youll agree that the idea of ENGINEER mode (besides panel programming) is to stop ALL tamper faults that occur while and engineer is on site doing routine maintenance and services. This includes the BellBox Tampers. The way you describe above with a Nova 2 will still cause the bellbox to sound when the panel is in engineer mode and the engineer removes the bellbox lid.

Why would an engineer intentionally wire these up backwards ?

Tamper Feed = Hold -

Tamper Return = Hold - return through the bellbox tamper circuit to the panel.

Fairly simple really.

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