Just twice so far this year? At two different locations?
Don't lose sleep over that. You're fine.
I've been to multiple calls from the same building - on the same day - after being warned not to repeat the process that generated the first call.
Here's a tip for you though:
If you are doing ANY kind of maintenance or testing though, my only suggestion to you is to CALL THE ALARM COMPANY AND NOTIFY THEM FIRST!
It depends on the alarm company as to what will happen next.
Some companies will ask you to estimate the time you'll be working (ie: 1300H - 1400H), so if an alarm is tripped during that time period, they'll hold off on dispatching the FD. If an alarm comes in at 1403H though, they will likely dispatch the FD.
Other companies will request that you call them upon the completion of the work.
False alarms are a part of the deal though, so most firefighters aren't irritated by them...but like anything, it's possible that you may encounter a cranky Captain/Lieutenant.