# Reply To: module 3 unit 2

#14080
Sam Brown
Keymaster

question 1 If you’re testing a pair of timer contacts using a voltage test (line voltage), what should you measure across those contacts if they are good (closed)?

I don’t understand how the answer could be 0vac. Wouldn’t there be voltage going through the contacts?

Voltage is not current — it doesn’t “move” or “flow”. It’s either present at a point or it’s not.

Furthermore, remember what we’re doing when we take a voltage measurement. We’re measuring the voltage difference between the two points where we place our leads. If you place your leads on either side of a closed switch (like a timer contact), there will be a voltage difference of 0 volts between those two points.

Question #3: In the video, what are the timer contacts switching for the motor speed windings?

When he traces the lines the there is both L1 and neutral being traced. I don’t understand how the question could only be neutral.

Timer cams 6 and 8 are responsible for determining whether the slow or regular winding is energized, and they do this by switching the neutral side of the power supply. That’s why we say that neutral is what is being switched to the speed windings.