Switches and Starters for Single-Phase Motors

Play an AI-generated podcast conversation about this lesson

What is the maximum horsepower rating for most toggle-switch starters?

1.5 hp @ 120 V

3 hp @ 240 V

5 hp @ 230 V

1 hp @ 230 V (correct)

At what voltage are most drum switches for single-phase motors rated up to 3 hp?

230 V

220 V

240 V (correct)

120 V

What is the maximum horsepower rating for push-button starters for single-phase motors?

3 hp @ 240 V

1 hp @ 230 V

1.5 hp @ 120 V

5 hp @ 230 V (correct)

According to the manufacturer's chart, what is the Catalogue Number for a motor with a Full-load Current of 4.40 – 4.79?

GGH 5.5A (A) Signup and view all the answers

If a motor has a Full-load Current of 13.68 – 15.12, what is the corresponding Catalogue Number according to the chart?

GGH 17.1A (D) Signup and view all the answers

What is the horsepower rating for single-phase manual starting switches with Catalogue Number GGH.89A?

~1.67 hp (D) Signup and view all the answers

What is the maximum horsepower for a plugging & jogging-duty poly-phase motor for EEMAC size 2 at 480 volts?

25 (B) Signup and view all the answers

In a motor controller, besides stopping and starting the motor, what is another function that a magnetic contactor can provide?

Overload protection (C) Signup and view all the answers

What distinguishes a magnetic contactor from a magnetic motor starter?

The magnetic starter includes an overload relay (D) Signup and view all the answers

What are the two basic components of a thermal overload relay?

Bimetallic strip and contacts (B) Signup and view all the answers

Is it necessary to have an overload in series with each of the line conductors to a three-phase motor?

No, it is not necessary due to inherent motor protection (B) Signup and view all the answers

What is the maximum horsepower for a nonplugging & nonjogging-duty poly-phase motor for EEMAC size 7 at 208-240 volts?

300 (D) Signup and view all the answers

What is the purpose of low-voltage protection in equipment such as saws and lathes?

To prevent automatic restart after a loss of voltage or in a low-voltage situation (B) Signup and view all the answers

What three significant electrical ratings are important for manual motor starters?

Voltage, current, and horsepower (D) Signup and view all the answers

Why is it crucial for the voltage rating of a starter to match the operating voltage of the motor?

To avoid damaging the motor or starter (B) Signup and view all the answers

How is the ampacity rating of a starter typically related to the overload protection device?

It refers to the current drawn by the motor (B) Signup and view all the answers

Why is it important for the horsepower rating of a starter to meet or exceed the horsepower rating of the motor?

To protect against overloading the motor (C) Signup and view all the answers

What should be avoided when selecting a manual starter based on its horsepower rating?

Using a starter rated above the motor's horsepower at a lower voltage (B) Signup and view all the answers