METREL MI 3399, Инструкция с упражнениями

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PAT Appliances & Machines Safety Trainer AD 3
– MI 3399
213
4 Basic theory
The primary goal of testing safety of electrical equipment is to use all electrical equipment
without danger. Common accidents caused by electrical equipment are:

Injuries through electric shock caused by malfunctioned equipment;

Injuries through overheated equipment;

Fire and explosions.
To prevent risk and possible danger caused by using electrical appliances and other
equipment appropriate safety testing procedure should be performed.
Testing of electrical equipment is not regulated the same way in all countries.
Safety of electrical equipment depends on different factors which can improve or worsen
the safety level.
According to the standards electrical equipment is divided in:

Electrical appliances.

Electrical equipment in medical use.

Electrical machines.

Electrical switchgears.
Types of safety tests of electrical equipment are:

Type testing.

End of line testing.

Maintenance testing.

Testing after modification and repair.

Periodic testing.
4.1 Safety management
The term safety management summarizes all necessary steps that must be taken to
assure the safety of electrical equipment through its complete lifetime.
This steps are:

Quality type testing performed by the producer

Obtaining an independent certification mark for the product (recommended)

A strict quality end control at producer

Quality maintenance of the product

Correct handling with the product according to product manuals and working
instructions

Often visual checks by the user

Regular safety check performed by a skilled person (visual check, testing of safety,
“Logbook” of appliance, documentation of tests, etc.)

Adequate corrective measures in case of a noticed safety problem. The figure
below shows how individual factors can improve / worsen the safety level of
electrical equipment