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higherrating if necessary.
6. A bi-metal strip consists of one piece of metal.
7. A bi-metal strip must cool before the circuit is complete again.
8. The current manual switch must not be switched off before
replacing the fuse.

Step 5

Put the correct words. Choose from this list.
rectified damage joining supply
piece should clips rated
must melts breaks of
blows manual occurs there
held cartridge

Every circuit... have a fuse in the ... to the equipment. The
fuse can be of the ... type, which is ... in position by two springs ...
or it can be a ... of ... two points in the circuit. Fuses are ... in
amperes and the rating ... be correct so that if ... is an overload ...
current, the fuse wire ... and ... the circuit before any ... to the
circuit wiring ... . If a fuse ... the correct ... switch (be switched off
and the fault ... before replacing the fuse.

Step 6

Explain the difference between automatic trip switches,
manual switches and fuses and why all electrical circuits must be
protected against current overloads.
Examine the electrical system and appliances in your
university, draw diagrams of the circuit and supply. Describe all
the protective devices, which you find.

LESSON 9

SAFETY AT WORK

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