tman
Prominent Member
I'm looking to install a Nest Hello smart doorbell. I have the low voltage wiring in place and an old-school chime unit. As with many, the transformer housed in the chime unit isn't powerful enough to support the Hello (a Friedland Type 4 8-16V unit), so like many I've picked up a Bell CUB1 8 to 24V replacement unit from Screwfix, which should be fine. Two problems though;
1. The new transformer is MUCH bigger than the existing one and will no longer fit in the chime unit, so I'm going to need something else to mount it in. I believe a standard DIN RAIL enclosure should work, but I just need a discreet housing that isn't too big (just for one transformer), and not too expensive. Any ideas?
2. I've been looking at the existing wiring too. It has 4 front mounted terminals; OF, 1 ,2 and T3. I have unmarked white wires going into OF and T3 and then two more white wires going into 1. I found an old Friedland wiring diagram for this transformer, and it seems to indicate that the link between OF and 1 is the doorbell circuit (on/off), then T3 and another connection from 1 go to the transformer (pinout 4b on the attached diagram). I just need to work out how to replace the transformer and integrate everything with the Hello unit!
I'm happy to do this myself, but for those who've already attempted it, advise would be awesome.
Thank
1. The new transformer is MUCH bigger than the existing one and will no longer fit in the chime unit, so I'm going to need something else to mount it in. I believe a standard DIN RAIL enclosure should work, but I just need a discreet housing that isn't too big (just for one transformer), and not too expensive. Any ideas?
2. I've been looking at the existing wiring too. It has 4 front mounted terminals; OF, 1 ,2 and T3. I have unmarked white wires going into OF and T3 and then two more white wires going into 1. I found an old Friedland wiring diagram for this transformer, and it seems to indicate that the link between OF and 1 is the doorbell circuit (on/off), then T3 and another connection from 1 go to the transformer (pinout 4b on the attached diagram). I just need to work out how to replace the transformer and integrate everything with the Hello unit!
I'm happy to do this myself, but for those who've already attempted it, advise would be awesome.
Thank