1.5mm2 section cable

Discussion in 'Grow Room Design & Setup' started by KLITE, Mar 8, 2014.

  1.  
    KLITE

    KLITE Well-Known Member

    Hi all

    An old friend is trying to set up 4 1000W lights. He has a 25A (at 220 V) contactor wired in a circuit with a 32 A breaker and with 6mm2 section cable. He has a fair bit of 1.5mm2 section cable kicking about, would that cable be alright for wiring the lamp to the ballast and the ballast to circuit with the contactor and the 6mm2 cable? I have had 600W running on 1.5mm2 cable for a very long time without anywires even getting warm or any other issues, though i wonder if itd be a tad tight for 1000W.

    Thanks in advance.
  2.  
    CAPSLOCK

    CAPSLOCK Member

    Hello. Finally someone using EU units and not the stupid AWG !!
    1.5 mm^2 is good for up to 25 amps of current (depending on the thermal insulation material). Your load seems to be less than half of it. Divide Power/Voltage to estimate current. If it's smaller it should be ok.
  3.  
    KLITE

    KLITE Well-Known Member

    Yeman check this. The shop where my pal got the stuff they were telling him to make the connection with 6mm2 and to get an extra 25 amp contactor for the other two lights and have them turn on 5 or 10 minutes apart from the other two because when each lamp starts up they start up with 10 times the potency and that you can burn the wires. And i was like wait? then what the hell are the contactors for? 4 lamps come to around 18 amps so i dont think theres any need for an extra contactor.. Plus all the cabling for the circuit is 6mm2 which can easily hold double the amount of power hes gonna be using.
    Apparantly it was the first time that shop sold 1000W lights. Everyone works with 400 and 600 here in Spain.

    Thanks for the help!
  4.  
    CAPSLOCK

    CAPSLOCK Member

    There is a thing called starting current - different devices use much bigger current than the nominal current when started. With motors it can reach up to 20X. Since HID lamps have pretty big starting current you need to use a "C" type breaker. It holds starting currents of 5-10X the nominal current. The contactor (relay) should be a good one, that fits motors, or you might have sticking contacts.
    Hope I understood you right.. You don't need to time the ignition if you're using a proper C or D type breaker. If you add a little drawing of your system maybe I can help more.
    KLITE likes this.
  5.  
    KLITE

    KLITE Well-Known Member

    I get you now. The breaker is actually 40 amp and It has a capital C before the 40.
    1 (2).jpg
    Heres the contactor box, a bit refugee style but everything is screwed tight and holding well.
    2 (2).jpg
    Heres where the ballasts connect thats enclosed inside another box that he took out to photograph, again everything is tight as hell and well grounded.
    3.jpg
  6.  
    CAPSLOCK

    CAPSLOCK Member

    Disclaimer - electrical guidance should not be given by means of telecommunication ..
    But... I it's a C40 it should hold very well. The wiring looks fine.
    If the cantactor is of good quality and designed for high power (most of them are), the contacts won't stick and everything will be alright.
    I think the guy in the store just tried to encourage you to buy more than you need..
  7.  
    KLITE

    KLITE Well-Known Member

    Nice disclaimer! Its a hager contactor, hager is pretty good i think.
  8.  
    CAPSLOCK

    CAPSLOCK Member

    Hager's good, get to growing !!! :weed:

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