Ask the experts/Technical
Fully charged For handlamps
Fig 2 Automatic disconnection of supply used in conjunction with additional supplementary bonding
The only protective measure permitted to be used for the supply to handlamps is SELV, in accordance with Section 414. The SELV supply may be used to supply a fluorescent luminaire operating at a voltage exceeding extra-low voltage, incorporating an integral step-up transformer having electrically separated windings (indent (ii) a) of Regulation 706.410.3.10 refers).
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Protective device
Fixed equipment
For fixed equipment
Source
The protective measure of automatic disconnection of supply in accordance with Section 411 may be used, provided this includes supplementary bonding in accordance with Regulation Group 415.2. The supplementary bonding should connect together all exposed-conductive-parts within the location (such as metallic conduits and equipment enclosures) and the conductive parts of the location itself (such as the metalwork of a boiler, vessel, duct or similar). Fig 2 refers. The protective measure of double or reinforced insulation in accordance with Section 412 may be used, on condition that the circuits supplying the equipment are provided with additional protection by RCDs having a rated residual current (Iﾎ馬) not exceeding 30 mA and an operating time not exceeding 40 ms at a residual current of 5 Iﾎ馬.
cpc
Fortuitous contact with earth
Additional supplementary bonding conductor
Fig 3 The use of SELV and PELV to supply any type of equipment in a conducting location with restricted movement (a) SELV
(b) PELV
Access Protective device
SELV source
Protective device
SELV circuit
Source
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SELV current-using equipment
SELV source
PELV circuit
PELV current-using equipment
Source
cpc cpc
56
Winter 2013-14 Connections
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