Power Fail event each time alarm is triggered

I get the following rule (power fail event) triggering every time my alarm is triggered (simultaneous with the alarm activating).
 
any ideas why ?
 
Ian

When the alarm sounds the system uses more current than usual so the first thing that I would look for is overloading of the power supply. Have you calculated the current draw of all of the devices on the system? The elk web site has a spread sheet that makes less work of it.
 
Mike.

You might also try swapping the panel's 16vac power transformer for a new one.

thanks for your comments - I will investigate

Bad battery would also come under suspect. If the panel is in alarm, it'll draw the extra power from the battery. If the battery is too small, aux power too close to the limits and what have you, could give the symptoms of an AC failure....or if the transformer is undersized or has an issue (assuming Elk) and PTC protected, possible issue combined with above.

Have you ever figured it out what causes the power fail?

Yep, think I've got it sussed.  As suggested by mikefamig above, I downloaded the M1-current-draw-worksheet, and stuck all the numbers in.  All seemed good until I remembered the two 12V screamers in my sheds - at 200mA each pushed the current drain above 1A and the spreadsheet suddenly says "auxiliary power supply needed"!
 
Off to the shops.....

I would test by disconnecting the screamers and maybe other items before spending any money or making any changes. It may help you to plan which devices will be off-loaded to the new aux supply.

the new power supply sorted the problem
 
thanks for your responses