A smoke damper has to operate if the power fails, so if its 230v with no battery back up supply it should be spring or gravity closing to fail "safe". In which case it wouldn't really matter what isolation or fuse protection is installed so long as it can be safely isolated for maintenance.

regards burn

A smoke damper has to operate if the power fails, so if its 230v with no battery back up supply it should be spring or gravity closing to fail "safe". In which case it wouldn't really matter what isolation or fuse protection is installed so long as it can be safely isolated for maintenance.

regards burn

burn said:

A smoke damper has to operate if the power fails, so if its 230v with no battery back up supply it should be spring or gravity closing to fail "safe". In which case it wouldn't really matter what isolation or fuse protection is installed so long as it can be safely isolated for maintenance.

I'm sure that's not always the case ... for example with smoke control or "positive pressurisation" systems, a "fail to close" might be just as bad as "fail to open".

True, but in those cases there would have to be secondary supplies with auto-changeovers to enable the damper to both close and open. From the original description I didn't think that was the case here.

burn

burn said:

From the original description I didn't think that was the case here

I agree that's probably the case, but the original question is rather brief and devoid of context.