help designing circuit

[flukey]

i have to put in a 20amp feed to a firemans switch that will isolate neon sign transformers.
the run is approx 100 metres from db to firemans swich position.
doing cable calcs the cable works out silly size.
there is a perforated tray from db to front of store with many other circuits already on.
am i right in saying that by incorporating a contactor i can reduce cable size somewhat??
any guidance very much appreciated on this one please.

 

[flukey]

cheers tony see you over there

 

[DanBrown]

i have to put in a 20amp feed to a firemans switch that will isolate neon sign transformers.
the run is approx 100 metres from db to firemans swich position.
doing cable calcs the cable works out silly size.
there is a perforated tray from db to front of store with many other circuits already on.
am i right in saying that by incorporating a contactor i can reduce cable size somewhat??
any guidance very much appreciated on this one please.

I've never done a fremans switch, but i would be considering a contactor, and switching the contactor via an inline firemans switch with Aux...

Hope this helps, or do i need help!.
Thanks anyway