Emergency lights dimly lit while on AC power?

[aerhardt]

I posted this recently:

@aerhardt

For some reason, many emergency lights in the store were on dimly, although they showed that they had AC power:

I’ve seen this a few times, where many emergency lights in a building will be on quite dimly at once, but the building has power, and their AC indicators are lit.

[KBM_Fire_andSecurity (SlyFox Alarms)]

I have definitely seen this before in buildings but don’t really have any idea why either., I was thinking maybe something on the particular circuit was messed up so that’s why they were? Like maybe there isn’t enough voltage for the units to register that the power is on so they believe that the power is out???