Testing Equipment and General Electrical
Ladder Logic Schematics
3 Phase Motors
100

What happens to Resistance, and current in a circuit when a Load is shorted?

Resistance goes down, current goes up!

100

What does N.O mean?

Normally Open

100

Name the two wiring configurations for 3 phase motor windings.

Delta and Wye

200

What voltage should I read with my Black lead at ground and my red lead at the positive side of a 9V battery?

+9V

200

What does N.C mean?

Normally Closed

200

In order to reverse the direction of rotation of a 3 phase motor what must I do?

Swap any two of the power connections to the motor windings. For example, Swapping L1 and L3, or L1 and L2 etc

300

How does your meter measure voltage?

The difference in voltage potential at my leads (Red minus Black)

300

What computer device primarily uses Ladder Logic as its main Programming Language?

PLC'S!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

300

What is the standard frequency and voltage for US homes?

120VAC at 60Hz

400

Before measuring Ohms I must do what?

Ensure power is off/disconnected from the circuit

400

In a ladder diagram, do we ever have two loads in series?

NO

400

This type of motor uses a copper band around a stator pole in combination with the stator windings to produce a rotating magnetic field using only single phase power.

Shaded Pole!

500

When performing a LOTO (Lock out Tag out) What are the steps I must perform in order to properly Lock out a piece of equipment (for ex. a 3 phase motor).

1. Notify your supervisor or coworker for the shutdown request. Make sure to notify all affected employees

2. Deenergize and tag the equipment

3. Lock out the power source

4. Sign that my lock has been placed on the equipment

500

Mr. Paine will draw a Ladder Diagram for you to troubleshoot. The customer does not know why but, when powering up the circuit he can hear a buzzing sound coming from inside the panel.

Doorbell!

500

What degree or angle must you cut the flux lines in a generator to produce the peak voltages?

90 and 270!

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