Clean supply?

[polo1]

Hi,
I have been asked to provide a "clean supply" for a new fire panel installation. What does the phrase "clean supply" mean to you guys. A clean earth - if so, how would you deliver this? Something different?????

Serious question, serious answers please!

Thanks,
George

 

[malcolmsanford]

It is basically an earth which as no noise on it ...................so clean and therefore no interference.

In this case I would imagine they will want you run a seperate circuit from the CU to the panel. Is this an actual Spec as the "clean Earth" term is mostly associated with older IT equipment and with modern day technology is not that critical. Is this an old panel?

 

[polo1]

Thanx Malcolm. A verbal rather than written spec for a new fire alarm panel. So in your eyes, a new radial circuit supplying only the FP. I'm guessing the guy spec'ing the new supply has picked up the terminology from somewhere, but I wanted to check my understanding before getting back to him. Does the cpc in a clean earth supply require to be a minimum size, or terminated in a special way?

George

 

[malcolmsanford]

Normally all that was done 15-20 years ago when computers and VDU were being fitted was that each station was fed from it's own individual radial. so if you had 10 stations you had 10 radials feeding them .................often in large offices you would see a sub board which these radial terminated into but, the CPC for that board still terminated back via however to the MET.

It was felt that by using individual circuits you cut down on the noise becasue you only had the one individual item of equipment on a circuit and so no interference. But as said most modern equipment have filters and that brings it's own joys .

 

[Guest123]

I know Kentec fire panels get really upset with external 'noise' on a system, so much so that I have had to fit diodes in the CPC circuit to filter out the nasty 'noise'!

 

[bugsy]

Clean supply would normally be taken from the intake position, as opposed to local DB