smoke alarm replacement brk model

[delb0y]

hi folks

was hoping someone can advise. replacing the smoke alarms wires i have on old coming out of celling are red blue brown the one unit even tho its the same make newer model has 3 wires but they are white brown and blue

the new unit brown is live, blue neutral so im guessing white is either earth or to interlink both units as i have two alarms.


the unit is a brk 670 mbx

 

[Gutterball]

what colour are the wires on the 3core& earth connecting the alarms? at one end you should have red/brown + black/blue of the feed. and red/brown + blue/gray + yellow/black of the 3 core. you should use the yellow/black of the 3 core as the interlink, but check the alarms at both ends first. i would assume the white and red on the alarm wiring is the interlink. do you not have the instructions with the new alarm?

 

[PrenticeBoyofDerry]

Did take note of the configuration of thee wiring of the unit removed? if not check at the other smoke alarm for configuration, and copy that.

 

[PrenticeBoyofDerry]

Did take note of the configuration of thee wiring of the unit removed? if not check at the other smoke alarm for configuration, and copy that.
We can only assume, red/brown are live, black/blue is neutral, as far as the brown from the ceiling, can you confirm this as I would expect a yellow.