S3 - Distribution Equipment

Question 1

The most common protective devices on the distribution system

Answer 1

Expulsion Fuses

Question 2

Used to protect overhead and underground primary taps, distribution transformers, and capacitor banks.

Answer 2

Fuses

Question 3

EPB uses this type fuse mounting

Answer 3

XS Fuse Mounting

Question 4

The most common type of expulsion fuses.

Answer 4

Type “K” for Kwik and type “T” for Tardy

Question 5

EPB’s mostly used type fuse links

Answer 5

T

Question 6

This depends on the downstream peak load current, available fault current and upstream protection devices.

Answer 6

Fuse Link

Question 7

This is sized to coordinate with the upstream devices, meaning it will interrupt the load for a fault behind it without any other upstream device operating.

Answer 7

The Fuse

Question 8

Used in most single phase pad mounted transformers and are also used in some of the large three phase pad mounted transformers at Hamilton Place Mall.

Answer 8

Bayonet Fuses

Question 9

The are two types of bayonet cartridges are:

Answer 9

Load Sensing & Fault Sensing

Question 10

A self-controlled device for automatically interrupting and reclosing an alternating-current circuit, with a predetermined sequence of opening and reclosing followed by resetting, hold closed, or lockout

Answer 10

Recloser

Question 11

Interrupting Mediums

Answer 11

Oil, Air, SF6, Vacuum

Question 12

The primary purpose of a reclosing device

Answer 12

To allow temporary faults an opportunity to clear themselves

Question 13

Uses springs and hydraulic systems for timing and actuation for reclosing

Answer 13

Hydraulic Recloser

Question 14

What happens if a temporary fault is located behind the recloser in ideal conditions?

Answer 14

Ideally one reclosing cycle permits the temporary fault to clear and service is restored to all the customers downstream

Question 15

What happens if the temporary fault is located behind a fuse downstream from a recloser in ideal conditions?

Answer 15

The fuse may blow isolating the fault from the mainline and interrupting service for customers downstream from the fuse, or the fuse may remain in tact long enough for the recloser to operate once on the fast curve. If the fault has cleared, service may be restored to all customers

Question 16

When reclosers are in service are bypasses open or closed?

Answer 16

Open, when closed the recloser has been removed from the circuit

Question 17

A type of reclosing device that interrupts the fault similar to a recloser, but instead of closing back into the fault to determine if the fault is still affecting the system this device pulse closes to intelligently test for fault current before closing.

Answer 17

Three Phase Pulse Circuit Recloser or Three Phase PulseCloser

Question 18

Are self-contained, circuit opening devices used in conjunction with a recloser, to automatically isolate faulted sections of a feeder

Answer 18

Sectionalizers

Question 19

This device senses current flow above a preset level, and when the source side protective device opens to de-energize the circuit, the device counts the overcurrent interruption.

Answer 19

Sectionalizer

Question 20

This device is set to count a certain number of interruptions and when it reaches the full count it will open, but this is device is not designed to interrupt fault current and can break load.

Answer 20

Sectionalizer

Question 21

This device is used to add a level of protection where other devices cannot be coordinated with the upstream or downstream devices.

Answer 21

Sectionalizer

Question 22

Devices used to control and route the flow of power through electrical lines

Answer 22

Switches

Question 23

This device is not a protective device that will automatically open for system faults

Answer 23

Switches

Question 24

Devices that can be used to drop load and are equipped with some method of extinguishing the arc when load is being dropped.

Answer 24

Load Break Switches

Question 25

This must be used when switching between two feeders off of different sources

Answer 25

Load Break Switch