How to wire a 3-Step controller to a fan (what kind of cable do I need?)

Discussion in 'Technical Repair' started by MThompson, Feb 1, 2018.

  1. MThompson

    Thread Starter New Member

    Feb 1, 2018
    I just received a small (1amp) in-line centrifugal fan and 3-step controller that I ordered, I thought wiring everything together would be pretty straightforward but I got stuck on something simple.

    I picked up standard electrical cable (GY BR BL) and a plug to wire the controller to my mains, but what can I use to connect the controller to the fan? Should I be using 5 individual wires and sheathing them myself? From what I can tell there's no existing 5-wire cable, am I supposed to make one or is there something I'm missing?

    Thank you in advance for the help!

  2. ericgibbs


    Jan 29, 2010
    hi MT,
    You can buy 5 core mains flex cables, cost will be a problem when only wanting a 'short' length.
    Another way would be to use two lengths of standard 3 core, if the cable grips will accept that.?
    E core cables&network=g&matchtype=b&ad_type=&product_id=&product_partition_id=&test=finalurl_v2&gclid=EAIaIQobChMIh-nQqbGE2QIVV80bCh2XtQayEAAYASAAEgJGR_D_BwE
  3. MThompson

    Thread Starter New Member

    Feb 1, 2018
    Oh that's an excellent idea using two 3-core cables! The fan actually has a second grip and hole to punch out so that would accommodate it perfectly.

    I just opened the controller box and there are no grips or openings at all. I was just going to drill into it but not sure what to do about the lack of any grips, is there a specific piece to seal and secure the cables that I should be using? I guess I can see if I can find some grip piece at the shop...

  4. MaxHeadRoom


    Jul 18, 2013
    You need a conduit to cab tire starin relief, you can get them at any electrical supplier.
    You need to drill the box accordingly.

  5. MisterBill2

    Distinguished Member

    Jan 23, 2018
    You can also use 5 individual wires in a twisted bundle, which may make keeping which is which simpler. One question is how long do the wires need to be to get from where you want the controller to be to where you are putting the fan. And will the wires be exposed or not. Another concern is the issue of radio frequency noise from the controller. Some controllers are "silent" while others generate a lot of noise and interfere with radio and TV reception. In some areas the electrical code forbids using the ground wire color code,(Green/yellow) for any function except earth ground. For a fairly small fan such as this you can use as small as #18 size wire. And in some areas you can use a flexible metal sheath known as "greenfield". So there is anothe r option.