Five Safety Rules For Work In And On Electrical Installations - Toshiba TCB-ACREDU1-E Manual

2.2

Five safety rules for work in and on electrical installations

When working in and on electrical installations apply, in order to avoid electrical accidents certain rules,
which are summarized in the ve safety rules according to standard series DIN VDE 0105:
1. Disconnect
2. Protect against reconnection
3. Determine the absence of voltage
4. Earth and short circuit
5. Cover or enclose adjacent components that are still live
These ve safety rules are applied prior to working on electrical systems in the above order. According to
the work they will be canceled in the reverse order.
For electricians, these rules are assumed to be known.
Explanations
1. According to the present operating voltage, di erent lengths separation sections are to be made
between energized and de-energized system component.
Unlocking is referred to in the electrical equipment and disconnect from live parts.
All-pole disconnection can be achieved by, for example:
- Turn o the circuit breaker
- Turn o the motor protection switch
- Unscrewing fuses
- Dragging NH fuses
2. In order to ensure that the branch remains unlocked during the work, it must be secured against
accidental reconnection. This can be achieved by e.g. the motor and system protective switch in the o
state by lock or by unscrewing the fuses is secured by lockable blocking elements.
3. To determine the absence of voltage using appropriate test equipment. For example, two-pole
voltmeter.
Single-pole test pins are not suitable. The supply must be observed at all poles (phase to phase, phase
to N / PE).
4. The earth and short circuit is greater than 1 kV mandatory only on systems with a nominal voltage.
In this case always rst the earth and then connect with the short-circuited active parts.
5. To avoid to touch inadvertently adjacent live parts during work, these parts have to be covered and
safeguarded.
TOSHIBA I 5