Accenta 6?

hi, twice now after a thunderstorm my alarm as gone off
even when it was'nt set, the bell in the hallway went off, I tried to put in my code, and it seemed to stop, but I noticed it was on tamper, I have lost my instructions has I not used the alarm for a long while, now the alarm is going off in the night, but the bell is not ringing and it sounds like a whirling, has this been done by the thunderstorm, it has never happened like this before, please can you tell me how to download the instructions, my alarm is Accenta 6, Thankyou