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WorksheetsProtection Method Part 1
Total questions: 25
Worksheet time: 13mins
The Burden of CT is...........?
The load of voltage transformer
The load of DB
The load of flicker test.
The load of current transformer
A Class 5P20 CT means 5 = % error, P = Metering class, 20 means = 20 times of rated current
TRUE
FALSE
The false operation of the protection relays connected to CT is caused because of.....?
Wrong connection of main power.
Disconnection of CT burden
Wrong connection of CT poles
All of mentioned
In CT the primary current flows from Primary 2 (P2) to Primary 1 (P1)
TRUE
FALSE
During electrical design, the persone who decide the rate of MCB is .......
The manager
The project owner
you
The designer
The cicuit breaker is a reusable protection methods.
TRUE
False
The Crocodile test lead is comply with GS38.
TRUE
FALSE
To track potential breakdown we must keep history of maintenance activities
TRUE
FALSE
Isolation in accordance with procedure is required before carrying out protection system Maintenance works.
TRUE
FALSE
Before working on a circuit, you must ........................... the power supply
Isolate
switch on
Hold
open
The maximum setting of a motor overload is finding by motor full load voltage
TRUE
FALSE
Which devise in below provide protection against earth fault and over current
RCBO
RCCB
MCB
fuse
Protection unit on power supply is called....?
Flicker Test
Crowbar unit
MCB
RCD
SELV required an earth connection
TRUE
FALSE
What is the BURDEN of CT.
The load of RCD
The voltage of current transformer
The load of current Transformer
The current of current Transformer
What is the recognized method for CT polarity test
Polarity test
Primary injection test
Continuity test
Electrical test
All exposed metal in electrical circuit should be ....
Earthed
Connected together
Kept away
Painted
What meter use for CT Flicker test
Voltmeter
Ammeter
Ohmmeter
All mentioned
RCD testing is carried out with supply present
TRUE
FALSE
Tripping current (It) for 100mA RCD to operate in 150ms is...
200mA
220mA
110mA
300mA
Base on BS-7671, which device below is not classed as a basic protection method?
Fuse
Isolator
RCD
Barriers
According to the British standards, Which of following is not cartridge fuse
BS-3036
BS-1362
BS-1361
BS-88
It is necessary to keep record of maintenance history activities, in order to ....?
Clean the area
Track potential breakdown
To build up the power system
To help isolate the circuit
Why it is important to keep CPC (Circuit Protection Conductor) connection secure all the time?
To insure cut-of the power
To insure operation of MCB
To isolate the system
To insure operation of circuit protection device
Which of the following is fuse open to atmosphere?
BS 1361
BS 7071
BS 1362
BS 3036
