Transcript BS 7671 and BS 7909

Health
Healthand
andSafety
Safety
Executive
Executive
ADIPS Inspection Body Conference 2010
Electrical Engineering
HSE Perspective
John Madden CEng FIET
Principal Electrical Inspector
Team Manager Scotland, Wales & West
Agenda
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BS 7671 and BS 7909
Arctic cables
Generators
Anything else for discussion
BS 7671 and BS 7909
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BS 7671 – Requirements for electrical
installations
– Covers requirements for LV power generation
& distribution systems
– Non-statutory, apart from in Building
Regulations
– Provides route to compliance with Electricity
at Work Regs
– Section 740 contains specific requirements
for amusement devices etc
BS 7671 and BS 7909
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BS 7909 Code of practice for temporary
electrical systems for entertainment and
related purposes
– Non-statutory standard
– Offers guidance on management and
control of event electrical systems, as well
as design issues
– Cross references BS 7671.
– Makes recommendations for inspection
and testing.
BS 7671 and BS 7909
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The two standards appear to be complementary.
– BS 7671 provides detailed technical requirements
that are treated as a benchmark technical standard
– BS 7909 provides a commentary on the application
of those requirements and how to manage electrical
safety at events
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There is no duty to comply with either of these
standards, but they do provide a useful and helpful
route to legal compliance.
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Are there problems from the ADIPS perspective?
BS 7671 Section 740
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The most controversial requirements appear to
be:
– 300 mA RCD at origin.
– 30 mA RCD protecting lighting and socketoutlet circuits and mobile equipment
connected by 32 A flex.
– Inspection and testing after each assembly
on site - open to interpretation, judgement
required.
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Are these problematic?
Arctic cables
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Flexible cables for use at low temperatures.
Main applicable standards are:
– BS 7919 Electric cables. Flexible cables rated
up to 450/750 V, for use with appliances and
equipment intended for industrial and similar
environments
– BS 6500 Electric cables. Flexible cords rated
up to 300/500 V, for use with appliances and
equipment intended for domestic, office and
similar environments
BS 7919 Table 44
The IET has advised that this
cable is suitable only for 110 V
applications. It is unclear why
this should be the case – the
standard clearly indicates
suitability for 300/500 V duty and
manufacturers certify their
products for this voltage range.
Similarly, cables to BS 6500 are
rated at 300 V so are suitable
for 230 V applications.
Do we have a history of
problems with this type of cable?
Generators
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A continuing cause for concern
– Inappropriate o/current
protection
– Badly made connections
– Access to live parts
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They are a crucial part of the
electrical system and should
both be safe and subjected to
routine inspection by a
competent person.
Generators
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It is my view that generators and supply cables
should be part of the ADIPS inspection regime.
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Where possible, amusement devices should be
inspected and tested with a generator connected,
preferably the one that’s being used operationally.
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Controllers should know how to connect them safely
and how to use distribution switchgear to distribute
power to multiple loads.
…..Any questions/comments?