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- All socket-outlet circuits rated not more than 32 A for
construction sites (where reduced low voltage, etc. is not used).
- All socket outlets supplying equipment outside mobile or
transportable units.
- All circuits in caravans.
- All circuits in circuses, etc.
- A circuit supplying Class II heating equipment for floor
and ceiling heating systems

100 mA
Applications
- Socket outlets of rating exceeding 32 A in agricultural
locations.
- Where Loop Impedances are too high, RCD ratings can be
calculated.

300 mA
Applications
- At the origin of a temporary supply to circuses, etc.
- Where there is a risk of fire due to storage of combustible
materials.
- All circuits (except socket outlets) in agricultural locations

500 mA
Applications
- Any circuit supplying one or more socket outlets of rating
exceeding 32 A, on a construction site

3 Make a written translation of the following:

The regulations recommend, therefore, that the preferred
method of earth fault protection for installations in TT systems be
achieved by RCDs, such that the product of its residual operating
current and the loop impedance will not exceed a figure of 50 V.
Residual current breakers (RCBs), residual current circuit
breakers (RCCBs) and RCDs are one and the same thing.
Modern developments in CB (circuit breaker), RCD and

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