I am repairing a door lock at an apartment block showing these symptoms.


A transformer feeding the MA-485 is outputting 19.25 volts...will this harm the unit.It is a 16 volt amplifier.

B when an apartment station depresses the door button the output at the amplifier terminals for the ac door reads 19.25 volts...but when it is released it only drops to 18.85 volts...which makes me think the relay is stuck on the amplifier.....bottom line do I need a new controller?

C the electric strike shows a rating of 24 vac? how could this function well on a 16 volt system?It appears to have been part of this system for some time..and the caretaker has said there are problems with the system as far as people getting in without being buzzed. what is the lowest voltage a 24 volt buzzer could activate at?