Author Topic: Scantronic alarm - transformer replacement  (Read 1157 times)

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Offline Bicurico

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Scantronic alarm - transformer replacement
« on: January 23, 2017, 09:29:27 pm »
Hi,

I own a Scantronic 9448 alarm system and the transformer got damaged - the coil burnt due to a current spike.

I went on eBay and bought a second hand transformer from a Scantronic 9600 system, which from the pictures looks exactly like the one I have. It has not arrived, yet.

Meanwhile, it occured to me to look at installation manuals for both devices and I found out that the Scantronic 9448 manual referes to a 21VAC intput connector from the transformer, while the Scantronic 9600 manual has a 19VAC connector.

My question is: what can possibly happen, if I connect the 19VAC transformer to my Scantronic 9448 board, which expects 21VAC? Is there like a +/-10% voltage tolerance? Or will the house burn down?

Thanks,
Vitor

Offline Muttley Snickers

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Re: Scantronic alarm - transformer replacement
« Reply #1 on: January 23, 2017, 09:56:21 pm »
It wont know the difference and I would be very surprised if it complained, most systems can run on anywhere from 16VAC to 22VAC and I've measured quite a few unloaded transformers/ power supplies/ plug packs output being much higher than the label without detrimental effects.
 

Offline Bicurico

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Re: Scantronic alarm - transformer replacement
« Reply #2 on: January 23, 2017, 09:59:48 pm »
Thanks for your reply.

I opted to ask the seller for a cancellation and he just refunded me.

I know nothing too bad would happen, but because this a house I am not living in, I felt even a minor risk was something I was not comfortable with.

Regards,
Vitor

Offline james_s

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Re: Scantronic alarm - transformer replacement
« Reply #3 on: January 25, 2017, 12:38:21 pm »
The difference between 19 and 21V is less than 10%, that's well within the normal tolerance on something like that. Your line voltage may well vary more than that over time.
 


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