Deck 4: Overload Relays

Question 1

Magnetic overload relays can be divided into two major types: electronic and ____________________.

Answer 1

dashpot

Question 2

What are the two types of thermal overloads?

Answer 2

Thermal overloads can be divided into two types: solder melting type or solder pot, and bimetal strip.

Question 3

What does it mean for a current transformer to have a ratio of 150:5?

Answer 3

This ratio means that when 150 amperes of current flows through the primary, which is the line connected to the motor, the transformer secondary produces a current of 5 amperes when the secondary terminals are shorted together.

Question 4

Fuses and ____________________ are designed to protect the circuit from a direct ground or short-circuit condition.

Question 5

Thermal overload relays trip faster when located in a cool area than in a warm area.

Question 6

Overload relays are designed to open the circuit when the current becomes 115 percent to 125 percent of the motor full load current.

Question 7

Magnetic type overload relays are sensitive to ambient temperature.

Question 8

Many bimetal strip type overload relays can be set for either manual or automatic reset.

Question 9

Fuses which are intended to provide both short circuit protection and overload protection are called ____________________ time delay fuses.

Question 10

How do magnetic type overload relays operate?

Question 11

Solder melting type overloads are often called solder ____________________ overloads.

Question 12

One common use for the normally open set of contacts on an overload relay is to provide an input signal to a programmable logic controller (PLC).

Question 13

Overload relays are divided into two separate sections. What are the two sections?

Question 14

What are the elements of a single pole double throw switch arrangement?

Question 15

Motor starting current is referred to as ____________________ current.