Honeywell wireless stat

[townfanjon]

Guys , I am sure one of you fine chaps can help me with this ....

Honeywell wireless stat . Receiver shows an obvious L and N and the remote unit is connected to A and B , I am pretty sure but dont want to blow a board are A and B just switching and have no mains voltage , could one of you confirm ... ?

Thanks in advance .

 

[Chuck]

If you are referring to a BDR91 receiver then you are correct, the A B (and C) terminals are 'cold', i.e. just go to a relay. You can make them 'hot' if circumstances require by including a link.

Diagrams, for example on page 3 of the CM900 installation guide:

http://www.honeywelluk.com/Documents/Full-Install/pdf/1069.pdf

 

[ShaunCorbs]

Lne as normal

Live from boiler to stat (A) and live from stat to boiler, heat call (B)

 

[Scott_D]

A&B are live to and switch live back

What boiler?

 

[townfanjon]

Sorry should have left more info , its a R6660D old one but its for an elderly customer who had the same one before , in other words she is used to it . Boiler is a Viessmann 050 and has a low voltage board ,or maybe volt free not 100%. So the A and B cant have any voltage .

 

[ShaunCorbs]

Sorry should have left more info , its a R6660D old one but its for an elderly customer who had the same one before , in other words she is used to it . Boiler is a Viessmann 050 and has a low voltage board ,or maybe volt free not 100%. So the A and B cant have any voltage .

They can doesn't matter and viessman have live out and live back in

 

[Chuck]

Sorry should have left more info , its a R6660D old one but its for an elderly customer who had the same one before , in other words she is used to it . Boiler is a Viessmann 050 and has a low voltage board ,or maybe volt free not 100%. So the A and B cant have any voltage .

Wiring for R6660D is shown here:

https://products.ecc.emea.honeywell.com/europe/pdf/en0h8557uk07r0906.pdf

Single-pole double-throw potential-free like the BDR91.

 

[townfanjon]

Wiring for R6660D is shown here:

https://products.ecc.emea.honeywell.com/europe/pdf/en0h8557uk07r0906.pdf

Single-pole double-throw potential-free like the BDR91.

Cheers pal , yep I am good with it , I was always sure it was potential free, I am a hard wired 6360 myself lol , this ones for a very old lady who just wants a dial , heating left on 24/7 , no programmer she wouldnt have a hope in hell working one .