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#200874 - 04/23/11 07:42 PM 5 ohm speed pot wiring
lite bulb Offline

Registered: 02/12/06
Posts: 77
Loc: wilm,de.
I have a 5 ohm speed pot to wire I ran a three wire shielded cable red, black, white, what is the proper color wiring.

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#200875 - 04/23/11 08:32 PM Re: 5 ohm speed pot wiring [Re: lite bulb]
NJwirenut Offline

Registered: 09/15/01
Posts: 816
Loc: Bergen County, NJ
Not enough information. What wire goes to what pot terminal depends on how the OTHER end of the cable is connected.

If I was wiring the whole system, I would wire it as follows, just out of habit:

Red---Positive voltage
Black ---Negative voltage (or ground)
White---Pot wiper (to drive speed input signal)

Typically, the Positive supply voltage goes to the CW terminal of the pot. This way, CW rotation produces a positive output voltage, and increasing speed. But this is subject to the specifics of your installation.

If this is a speed control pot for use with a VFD or something like that, typically it is set up as a variable voltage divider across a DC reference supply, to provide a 0-5V, 0-10V, +/-5V, or +/-10V speed command signal. You should ground the shield only at the drive end, and leave it float at the pot end.

5 ohms is a very low value for a speed control pot. Are you sure you don't mean 5 kilohms (5,000 ohms)?

Edited by NJwirenut (04/23/11 08:36 PM)

#200994 - 05/02/11 12:39 AM Re: 5 ohm speed pot wiring [Re: lite bulb]
Scott35 Offline

Broom Pusher and

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Agree with NJwirenut per the Colors -vs- Position on the Pot (Potentiometer).

With the Device's Shaft facing towards you:

  1. "RED" - to "Left-Side" of the Resistor (Terminal #1), for the Input Lead (DCV+ / Vss),
  2. "WHITE" - to the "Center / Wiper Lead" (Terminal #2), for the Loop-Back Lead,
  3. "BLACK" - to the "Right-Side" of the Resistor (Terminal #3), for the Ground Lead (DCV- / Vcc).

Terminate the Drains & Shields of all Cables at one common point. Isolate the Drain and Shield at the Pot, with Electrical Tape.

-- Scott
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!


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