I changed wiring on my LED array. I switched from a 24 AWG to 18 Gauge cable. I used the following potentiometers. However after changing wiring, all potentiometers (tried new ones and unused) started heating up really fast and slowly turning off probably from overheating protection. A significant change was that I increased the length of the wiring by 6 feet.
Any idea on what could cause that? If I plug the LEDs directly into the power supply they work fine for prolonged times.
The change in wire gauge means more current can flow. I expect you're getting too much current through the pulse width modulator controllers you linked to.
24AWG wire has a higher resistance per foot than 18AWG wire. I expect the higher resistance of the 24AWG was keeping the current below the rated current of the controller. You switched to thicker wire with less resistance, so there's more current going through the LEDs and the controller. That additional current is making the switching transistor in the controller get hot.
They ought to heat up because you used 18g wire which is way thicker than the recommended 24g wire. There was excessive current drawn due to the very low resistance of the replacement wire. Squaring that current (I2R) explains the excessive rise in heat.
Go back to the 24awg wire that's the before. Simple.
