Omega Owners Forum
Omega Help Area => Omega Electrical and Audio Help => Topic started by: VXL V6 on 01 June 2010, 21:02:33
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I think Kevin Wood has discussed this before now. I'm considering fitting an inline fuse in the powersounder +12V feed, Where would be the best place to tap into the loom (I'm guessing the nearer the battery the better) and what fuse rating would be best?
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Remove the dam thing and re-install it on a shelf in your garage
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I think Kevin Wood has discussed this before now. I'm considering fitting an inline fuse in the powersounder +12V feed, Where would be the best place to tap into the loom (I'm guessing the nearer the battery the better) and what fuse rating would be best?
Got to ask, Why ?
Powersounder problems come from internal battery, and fuse isn`t going to help you.
:-?
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I think Kevin Wood has discussed this before now. I'm considering fitting an inline fuse in the powersounder +12V feed, Where would be the best place to tap into the loom (I'm guessing the nearer the battery the better) and what fuse rating would be best?
Got to ask, Why ?
Powersounder problems come from internal battery, and fuse isn`t going to help you.
:-?
;) ;) ;)
http://www.omegaowners.com/forum/YaBB.pl?num=1275069219
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Doesn`t answer the question.
Exctly HOW is an EXTERNAL fuse going to solve the problem that is caused by the INTERNAL battery ?
They can still catch fire if unplugged !!!!
:-?
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There are many tell tale signs that the sirens internal battery is on its way out, from beeping when starting the car to randomly sounding - and if you catch it at an early stage, you can replace the batteries and it will last for quite a long time before it needs any further attention.
If ignored, then the batteries leak acid over the circuit board, heat up and can combust with the plastic of the siren catching fire. The rest of the car can then follow, as there are very few regulations with regards to fire retardancy of a car interior (makes me wince when I see people smoke in a car - if only they knew!)
A fuse isn`t going to stop this, and other makes of battery backed up sirens suffer from the same thing as well, its not just an omega thing and remember that disconnecting the siren will undoubtedly invalidate your insurance.
Changing the batteries is a time consuming and fiddly job, but not exactly rocket science, and there is a very good "how to" somewhere on here
(perhaps someone could link to it?)
:y
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Doesn`t answer the question.
Exctly HOW is an EXTERNAL fuse going to solve the problem that is caused by the INTERNAL battery ?
They can still catch fire if unplugged !!!!
:-?
I'd be surprised if that damage was caused by a pair of (failed) 3.6v 140mAh batteries. It's the leakage from the dead batteries that causes the failure, after all!
More likely the permanent 12v feed to the power sounder. (0.75 mm2 wire protected by an 80 Amp fuse).
The best policy is to remove the sounder, agreed, but I'd put money on an inline fuse in each supply to the sounder significantly reducing the risk of an inferno, for those who want to keep one.
Kevin
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Nope,
Got to disagree with you there. As a Sigma Alarm specialist I am aware of a few instances where powersounders have been removed and found themselves at the back of a workshop to have been found "smoldering" a few days later. Granted, a vehicle battery connected to them is potentially going to speed up the process, but certainly is NOT the cause of it.
For those of you who are still intent about removing them (against my personal opinion) I would strongly suggest NOT to keep them in the garage or the shed, but to dispose of them correctly.
But I must stress again, changing a faulty battery prevents this from happening, so if you are at all worried about it, follow the "how to" link and change them, or if beyond your capabilities, replace the siren for a new one with new batteries and have another 5 years trouble free.
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Must agree with Dave strongly,,,,
Fit alarms of many types for a living (or my engineers do!!)
Have had THREE instances of powered sounders catching fire or gently smouldering in their boxes when their batteries leak.
Didn't think it was possible, but found some "old stock" a few months ago, unused and never fitted. RED HOT casings......
DON'T DO IT.......REMOVE IT.
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I'm not saying there isn't a possible failure mode where the internal batteries provide the source of ignition. Rechargeable batteries in good condition can, of course, deliver high currents for short periods of time and this may just be enough to start a fire.
(That's an entirely preventable problem as well, of course. A PCB mounted fuse in series with the batteries inside the sounder would have avoided that scenario.)
Those sounders I've post-mortemed have had completely dead batteries but were starting to draw current through the 12v permanent supply due to leakage near the transistor that drives the sounder.
In any case, a stand alone sounder fire won't be enough to burn through the bulkhead and trash the interior of the car. That is surely down to inadequately protected wiring in the vehicle? Hence my recommendation of an inline fuse to prevent a dying / burning power sounder from overloading the wires that supply it.
I really think these devices and their installation has been based on the flawed assumption that omitting safety devices provides greater security.
Kevin
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And bad original design regarding function, too. All ours have a keyswitch fitted that isolates the internal battery, but still allows the sounder to function, but without battery backup.
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Rechargeable batteries in good condition can, of course, deliver high currents for short periods of time and this may just be enough to start a fire.
Agreed - but they can still give a fair amount of current whist deteriorating, BEFORE they have died completely
(That's an entirely preventable problem as well, of course. A PCB mounted fuse in series with the batteries inside the sounder would have avoided that scenario.)
I see where you are coming from, but a fuse would only have prevented any current draw of the rest of the circuit, if the batteries themselves have failed internally and started to heat up rapidly, then no amount of fuses or protection circuits is going to prevent this. A fuse will only protect anything connected to it.
Those sounders I've post-mortemed have had completely dead batteries but were starting to draw current through the 12v permanent supply due to leakage near the transistor that drives the sounder.
Agreed, but there are two issues here. The first is the dead batteries that you have seen. Once the acid has leaked out and the batteries are indeed completely dead, the risk of combustion has usually passed. This sounder is no longer failing, it has failed. The second issue is indeed the corrosion that is normally found around said transistor. If you measure the current draw and take an average over many failed sounders, you will notice that the draw is usually less than 750mA. The supply to the siren from the car battery is only intended to recharge and keep topped up the internal siren battery voltages, but when it fails, its enough to give enough of a battery drain to flatten the main car battery overnight, but certainly not enough to cause any combustion. This battery drain is a usefull sign that the sounder is faulty - if its only just started to drain the car battery, then change the internal batteries before its corroded to badly to salvage the siren.
In any case, a stand alone sounder fire won't be enough to burn through the bulkhead and trash the interior of the car. That is surely down to inadequately protected wiring in the vehicle?
Siren gets hot when failed - nothing to do with wiring. Hold a lit match to the soundproofing of the car and prove me wrong !! The automotive industry does NOT have any fire regulations when it comes to soundproofing or vehicle interiors - plastic wiring sheaths pass through bulkheads and can often be a good route through for any heat - fire will burn - simple as that.
Hence my recommendation of an inline fuse to prevent a dying / burning power sounder from overloading the wires that supply it.
The inline fuse offers no protection - if it does overload teh car battery, it is only a small amount that will cause battery drain as mentioned earlier
I really think these devices and their installation has been based on the flawed assumption that omitting safety devices provides greater security.
Not sure what you mean by this? The sirens and sounders work fine - BUT !!! Do require some preventative maintenance once in a while in changing the batteries. No battery lasts forever, especially rechargeable ones, and like any other, if neglected, WILL cause problems.
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And bad original design regarding function, too. All ours have a keyswitch fitted that isolates the internal battery, but still allows the sounder to function, but without battery backup.
The keyswitches used to be frowned upon by Thatcham initially, have they now approved these then as its only the battery that is isolated and not the sounder?
:-?
Still wouldn`t stop the problem though, battery could theoretically fail without being soldered to the board !!
:-X
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Correct.
I suppose the thinking behind it was two-fold.....firstly to make the sounder sealed, obviating the need to connect a battery feed lead at time of installation by the engineer, and guaranteeing watertightness, and secondly, allowing the engineer to isolate the battery from the circuit for service/maintenance and prevent sounder going crazy whilst fitting/removing.
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Correct.
I suppose the thinking behind it was two-fold.....firstly to make the sounder sealed, obviating the need to connect a battery feed lead at time of installation by the engineer, and guaranteeing watertightness, and secondly, allowing the engineer to isolate the battery from the circuit for service/maintenance and prevent sounder going crazy whilst fitting/removing.
They never do that do they ! Who`d have thought !!
::) :P ;D ;D
Out of curiosity, what make are you fitting currently?
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After reading all of this I asked at the dealers today how much a new one is on trade card and the man he said £55.97 part number 9194455 does this sound correct.
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After reading all of this I asked at the dealers today how much a new one is on trade card and the man he said £55.97 part number 9194455 does this sound correct.
price sounds about right from what i've read on here, not sure on the part no.
so, best place for the fuse then Dave? ;D
cant do any harm surely?
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After reading all of this I asked at the dealers today how much a new one is on trade card and the man he said £55.97 part number 9194455 does this sound correct.
price sounds about right from what i've read on here, not sure on the part no.
so, best place for the fuse then Dave? ;D
cant do any harm surely?
Agreed, price sounds about right, but I cannot confirm part number either.
:-/
Best place for the fuse? In the packet it came in, it does not need one, and would not benefit from one.
::)
And if you think that it would not cause any harm by fitting one, well actually, it might !! The thatcham category one alarm status as required by your insurance company would be null and void if an in line fuse was fitted, or if the alarm was tampered with in any such way, as this would contravine the very strict installation specifications.
;)
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Best place for the fuse? In the packet it came in, it does not need one, and would not benefit from one.
::)
And if you think that it would not cause any harm by fitting one, well actually, it might !! The thatcham category one alarm status as required by your insurance company would be null and void if an in line fuse was fitted, or if the alarm was tampered with in any such way, as this would contravine the very strict installation specifications.
;)
...and thereby lies the problem of just removing it... the vehicle is insured as having the standard VX alarm setup and knowing how much insurance companies like to wriggle out of things it's feasable that should the car be stolen / recovered and the vehicle is checked thoroughly the missing powersounder could be noted......
Tempted to remove the powersounder, open it and unsolder and remove all the components except the loom connector, then put it all back in place so it looks complete ;D
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Tempted to remove the powersounder, open it and unsolder and remove all the components except the loom connector, then put it all back in place so it looks complete
Dont be silly !! You would get found out very quickly if the car went up in flames and it wasn`t the powersounder that caused it !!
:P ;D
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Tempted to remove the powersounder, open it and unsolder and remove all the components except the loom connector, then put it all back in place so it looks complete
Dont be silly !! You would get found out very quickly if the car went up in flames and it wasn`t the powersounder that caused it !!
:P ;D
;D
Well I could sell the batteries to anyone who needed to 'release the value of their automotive asset' in these hard recession times..... ::)
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;D ;D ;D
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When replacing batteries in a power sounder I have fitted these...
(http://www.component-shop.co.uk/images/battery/400_6vp2600aa-h.jpg)
...externally.
Easy to test and replace and if they leak they won't leak on the PCB!
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When replacing batteries in a power sounder I have fitted these...
(http://www.component-shop.co.uk/images/battery/400_6vp2600aa-h.jpg)
...externally.
Easy to test and replace and if they leak they won't leak on the PCB!
Although I can see the logic in what you are doing, sadly that would not be sufficient to satisfy the insurance company with regards to keeping the alarm within spec.
Basically, and in laymans terms, the alarm powersounder criteria is that the siren must have an internal and uninterruptable power supply that is capable of sustaining the alarm sounder for a period of not less than five minutes, and that during that five minutes of operation, it should not be possible to deactivate the siren with or without the use of tools as part of its attack test specification.
But I must confess to really liking the idea of using something a bit beefier, plug in, commercially available and of a design not so prone to failure. How about something like small telephone or radio control car batteries fitted inside the sounder on a similar plug type arrangement? Food for thought?
:-?
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First time I tried I used 2 x 3.6v pack like above, ran them in series and they fitted inside the sounder itself (that's why I went for the 2 due to size). If I could find a smaller 7.2v pack I may go back to inside the sounder itself. As for removing them in an alarm state, Mr. T. Hief would have to know they were there and remove half the skuttle to get at them ;) ;D ;D