Security & Fire Protection Systems/hard-wired smoke alarm indication question
I live in a double wide mobile home that is 8 years old. It came with a hard-wired smoke alarm system. There are 6ea. Kidde Model 1276 alarms (w/battery back up) in the house. There are 2 on one half of the house, and 4 on the other. A couple of months ago, one of the alarms started chirping during the night. My wife changed out the battery with a new one (didn't do any good). Next day we noticed all the smoke detectors on one side to no longer have the steady green light, but to have the red light blink every 30 seconds. We changed out ALL the batteries in the four alarms that were blinking red but never got a green steady light. On the other side in the two bedrooms the alarms have steady green lights. What can we do to troubleshoot, isolate and fix this issue, or is it beyond simple repair?
Understanding the LED indication of the units is the answer to resolving your issue.
There are two LED's on the Kidde 1276 as you have quite rightly identified - a red and green LED.
The colour(s) operating and how they are reacting indicate the status of the units. The red LED has two modes of operation:
The red LED will flash every 30-40 seconds to indicate that the smoke
alarm is operating properly, regardless of power source.
When the alarm senses products of combustion and goes into alarm, the red LED will flash rapidly (one flash per second). The rapid flashing LED and pulsating alarm will continue until the air is cleared.
When the units are interconnected, only
the red LED of the alarm which senses the smoke, or is being tested (the originating unit), will flash rapidly. All other units in the interconnect system will sound an alarm but their red LEDís will NOT flash rapidly.
The green LED also has two functions:
The green LED will be steady on, indicating the presence of AC power.
This smoke alarm is equipped with an alarm memory which provides a visual indication when an alarm has been activated. A flashing green LED indicates the memory condition. The memory will remain activated until it is reset by pushing the test button.
So, understanding this LED operation, I can tell that if one side of your house has lost the steady green LED on the detectors, it is because the mains power supply to those devices has dropped and changing the batteries will not rectify this issue. This can be confirmed by removing the detector from the base and using a voltmeter, or multimeter, check for a voltage at the connections.
You need to trace back and identify the point at which the power is lost. It may just be a fuse blown within an isolating device, a MCB or fuse within a distribution board or a break in the supply cable itself. Either way, once found and repaired, this should resolve your issue.
If you have any further problems, please feel free to contact me again to follow up.