INSPECTION & TESTING OF FIXED WIRING INSTALLATIONS
FREQUENTLY ASKED QUESTIONS
What is fixed wire testing?
Fixed wire testing is the testing of the wiring within the fabric of a
Is it necessary?
Yes. It is a mandatory requirement of the "Electricity at Work
What happens if we fail to have it tested?
Failure to carry out such testing is likely to invalidate your
insurance cover in the event of a claim. Also, you may have a personal
duty of care to the employees and by endangering their lives you could
be held responsible and prosecuted, under the HSE laws. The HSE
inspectorate carries out routine inspections.
How often should it be done?
In a normal office environment, combined inspection and testing should
be carried out no less than once every five years, with a yearly visual
inspection. Some larger buildings have 20% inspected and tested every
year, with a 100% visual, to cover the five-year cycle.
Who does it?
A competent person, with knowledge of the electrical system, will carry
out all works. (See competency section towards the end of this guide).
The engineer will have all the relevant qualifications appertaining to
the works undertaken in accordance with BS 7671 Guidance Note 3.
What does it entail?
A full operational process can be found at the end of this guide.
How long does it take?
That depends on the size of the building and the intricacies of its
Is it done during normal office hours?
This may be possible, but most works are effected outside of normal
working hours to minimalise disruption to customers and staff.
Does it entail the powering down of our supply?
Quite simply - yes. Testing involves the testing of the circuits both
when they are ‘live’ and when they are ’dead’.
How long for?
Sometimes for as little as 10 –15 minutes, but in order to verify
that the incoming supply is safe you should allow for a total
power-down of the system for approximately 1 hour. Please note that
individual circuits will be isolated from the supply intermittently
throughout the works, not just for this initial 1-hour period.
What are the implications for our I.T systems?
Many of today’s IT systems are server based, often with the
server itself benefiting from a UPS (Uninterrupted Power Supply).
Whilst the UPS system provides a temporary back-up supply, the servers
themselves should be shut down during testing works to enable the
testing of the final sub-circuits. Usually where we find comm’s
and computer rooms, these areas are tested first to enable IT Managers
to reboot all their computer systems and minimise disruption.
What happens if faults are found?
These are recorded and presented to the client in the form of a defects
report. A plan of action is formulated and remedial works are carried
out. If a fault is found to pose a danger to the building or the people
in it, we will seek authorisation to carry out emergency repairs
without the need to lock off the system.
Are any records kept, and if so by whom?
Both parties will keep a copy of all test results, defects reports and
certificates as proof of maintenance
General Inspection of Installations
Installation will be visually inspected to check for correct
installation, assembly and mounting. Missing bolts, unfilled cable
entry holes, broken corners, damaged cables, open panel doors, etc.,
will be identified and reported.
Conductors and Terminations
Exposed conductors will be identified and tested to prove whether they
are LIVE or DEAD. If they are LIVE, or can be made LIVE, we will
indicate whether sufficient barriers, screens or divisions can be
positioned to prevent touch. We will also indicate whether
the conductor can be placed out of reach. generally we would identify
any LIVE conductors, which were not already protected by enclosures to
IP2X (BS 5490-Degree of Protection of Enclosures) and suggest course of
action to rectify. All cable entries to enclosures will be inspected to
make sure that they are properly glanded with no inner cores exposed.
Flexible conduits and tubing containing electrical cables will be
checked for damage.
Circuits will be inspected to ensure that they are adequately protected
to clear overloads, earth faults and short circuits. Protective devices
will be identified (e.g., circuit breaker or relay) and tested to
ensure they clear the above faults. Results will be compiled and copies
supplied if required. The protection system will be checked to ensure
that faults are cleared locally and do not cause interruption or other
Joints and Connectors
Joints and connectors will be inspected to assess whether they meet the
requirements of electrical conductivity and insulation. Connectors will
be checked for corrosion, electrolytic action, overheating and security
Isolation and Cutting Off Supply
Machinery will be checked for means of isolation (e.g., one stop
button) and its accessibility. The isolators’ condition and
operation will be inspected to check for broken handles, etc., or any
impediment in the operation. The system will be inspected to ensure the
circuit is provided with adequate means of isolation at the mains
switch room and at the respective distribution points.
All isolation points will be inspected to ensure that they are clearly
marked for the circuits they control, (this will also include
identification of fuse ways within distribution boards).
All circuits will be checked to ensure that they have a means of
All conductive parts, i.e., pipes, radiators, taps, etc., will be
checked to ensure they are efficiently connected to earth. If visible,
the earthing protective conductor will be examined for tightness and
the colour coding of the earthing protective conductor will be checked
to make sure it is green, or green/yellow. Earthing from the supply
authority will be identified and the Earth Loop Impedance will be
tested. Results will be compiled and copies supplied to your
In accordance with the law, all work by TCS will be done with the
supply removed, i.e., DEAD.
TCS will implement a “SAFE SYSTEM” to ensure that when the
supply has been removed for work to be done on dead conductors, it
remains off until all works are completed. If a “safe
system” is already in place, TCS will require a demonstration of
Safe System Procedure
• Where possible, all circuits to be worked on will be clearly
• Circuits to be worked on will be isolated and locked off.
• The circuit will be proved to be dead before work commences.
• Warning notices will be used in work areas.
• Engineers will use personal earthing equipment where necessary.
• Where possible, switch rooms will not be accessible to anyone
engineers who will carry keys.
• Where testing requires more than one engineer, constant
will be kept via hand held 2-way radios.
Fixed wire test engineers are fully qualified to 17th Edition standards
and hold a BS2391 certificate. At anytime there will be at least one
fully qualified engineer to BS2391 on site. In addition, all engineers
who complete testing and inspection will: -
• Be aware of the dangers and how to avoid them.
• Be happy with their levels of training.
• Know what is expected of them.
• Be confident that they can complete the job without risk to
• Be provided with all the necessary information to do the job
• Be satisfied with supervision provided.