Contactor/relay

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Mr T

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evening all...

a job im on at the moment involves fire alarm, gas interlock and 2 speed controllers for air intake and extract...

I want the fire alarm to shut down the speed controllers..

The speed controllers have a thermal protection link which when removed means the controllers dont work..

we have a fire alarm interface with com,nc or no..

it is as simple as taking a t&e into the  interface connecting brown to com and blue with brown sleeving to nc

then connecting the other end of the t&e's brown to a 230v supply (spur) and the blue sleeved brown to a1 on the coil (neutral from the spur to a2) and then simply extending the link from the controller through the contactor..

so 230 v onto the interface nc >230 down to a1 energise the coil making contactor go NC completing the circuit back through the controller ???

 
Is the relay volt free?

is the relay capable of switching this load?

you may need to installa second relay which is controlled by the first relay BUT is capable of switching the increased load.  If you go down this route then you may need an auxillary power supply if the PSU of your panel is not big enough

just saying

 
real job canoe but im also still a student so thought id post it in here so others may find it useful..

the fire alarm interface contacts can take 230 v and the relay is a 230 v coil rated at 10 amp which can handle the load..

 
don't see what the thermal link has to do with it? Fire panel used to control relay, wire supply to speed controllers ( or the fans) via relay. Fire alarm goes off, triggers relay, shuts off power - simples

 
the speed controllers are three phase binky and we are limited for space so rather than install a 3 pole contactor (also more wiring) the thought was a small 2 pole contactor that basically switched the link ( the speed controllers shut down when the link is removed)

 
how about contacting speed controller manufacturer and asking if they have a solution, it's not a new problem, but as being discussed elsewhere, you may be contravening CE regs - effectively it sounds like you are redesigning the controls??

 
the controllers are schneider...OK I will discuss this further and do some more research starting with the manual

 
its better that way, tempting though it is to throw a simplish mod of your own in everything should be CE marked and certified so it could leave you open to litigation if your mod failed, plus you may invalidate any warranties. Life just isn't simple anymore :C

 
Also please remember for your own sake, that if you are "self-employed", or even 1 man Ltd. Co.,  your public liability insurance will not cover you for design errors, thus if the worst happens and the building is destroyed & people are killed and the building / client insurer puts the blame on your mod / work / design, your public liability insurance will not cover this eventuality.

For "intangible" "advice" such as design like this you need to be covered by suitable "professional indemnity insurance".

HTH.

 

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