Veritas 8C?

Our house is undergoing a full restoration, so the electricity has been turned off at regular periods over the last few weeks. This is causing problems with our alarm, my sparky has found out that everytime the power is turned off the alarm sounds and it blows the f1 fuse inside the alarm box.He as replaced the fuse several times over the last few weeks. What we don't understand is why it blows the fuse when we turn the power off, we are thinking a dusty environment is to blame and maybe it's got into the electronic circuitry. We have now shut the alarm down until the work is finished, can anyone shed some light on why it keeps blowing the fuse and can the whole circuit board be changed?, if so at what cost and where can I buy one, thankyou to all that can offer help.