BS 6182-1:1994

Committees responsible
Foreword
Specification
1 Scope
2 References
3 Definition
4 Information and requirements to be agreed and to be
     documented
5 Design and construction
6 Marking
7 Routine tests
Annex
A (informative) Guidance on interconnection with
     other equipment
Tables
1 Output characteristics
2 Component specifications
A.1 Maximum inductance of cables and load for
     connection to the output of the power supply
Figure
1 Circuit arrangement for intrinsically safe d.c.
     power supply
List of references

Specifies construction and testing of mains-input intrinsically safe 18 V, 12 V and 7.5 V d.c. output power supplies.

This Part of BS 6182 specifies requirements for the construction and testing of a range of power supply units intended to be certified intrinsically safe for use in coal mines and which provide an intrinsically safe d.c. output as follows:

1. an 18 DC type power supply provides a nominal 18 V output that may be used, for example, to float charge an intrinsically safe battery with a nominal discharge end-point voltage of 12 V;
2. a 12 DC type power supply provides a nominal 12 V output for use where battery standby is not required, or to float charge an intrinsically safe battery with a nominal discharge end-point voltage of 7.5 V;
3. a 7.5 DC type power supply provides a nominal 7.5 V output that may be used, for example, with equipment using logic circuits requiring 5 V for operation.

It is intended that the components forming the power supply circuit be assembled on to a chassis that may be incorporated within either a flameproof enclosure or, where the power supply is located outside a potentially explosive atmosphere, within some other suitable enclosure. Requirements for these enclosures are not given in this standard. Guidance on interconnection with other apparatus is given in Annex A.

In addition to the definitive requirements, this standard also requires the information detailed in clause 4 to be documented. For compliance with this standard, both the definitive requirements and the documented item has to be satisfied.