This document provides guidelines for working on low voltage apparatus. It outlines general requirements, dangers, and procedures for working on both isolated and live apparatus. When working on isolated apparatus, all points of isolation must be locked or caution notices affixed. Live work is only permitted when suitable precautions are taken, like using insulated tools and protective equipment. Workers must be trained and verify apparatus is de-energized before starting. The document aims to prevent electric shock, burns, and other dangers to personnel maintaining low voltage electrical devices.

1. KTPS COMMON PROCEDURE
KC-PR-SAF-012
PRESENTED BY
MAVIS EGHAN
LOW VOLTAGE APPARATUS

2. Introduction
•LV apparatus are the electrical devices that are
rated for bel0w 1000V.
•Basically we have 415, 3 phase and 240, single
phase apparatus.These include motors, heaters,
lighting, etc.

3. Dangers
The main Dangers to personnel working on or testing LV
Apparatus are electric shock or burns arising from:
• The possibility of personnel mistaking that part of
Apparatus on which it is unsafe to work without special
precautions, for that which is Isolated and on which it is safe
to work.
• The possibility of the Apparatus being worked on
accidentally or inadvertently being made Live
• Inadequate precautions being taken under Live conditions

4. General Requirements
•Apparatus on which work or testing is to be carried out
should, where reasonably practicable, be Isolated.
BUT
Much as this will not always be possible, no person must
be engaged in any work or testing on or so near any bare
Live conductor.

5. General Requirements
•It is also unreasonable that in all circumstances the
apparatus will be dead.
•It is reasonable in all the circumstances to be at work
on or near Live apparatus
•Suitable precautions (including where necessary the
provision of suitable protective equipment) are taken
to prevent injury.
•The Senior Authorised Person must also consider the
conditions the work or testing is to take place and if a
Safety Document is to be issued.

6. Note:
•Although Live testing may be justifiable it does not
follow that there will necessarily be justification for
subsequent repair work to be carried out Live.
•Where work or testing is to be carried out on
Apparatus which is part of HighVoltage (HV)
Apparatus, adequate precautions must be taken to
avoid Danger from such HV Apparatus and an
appropriate Safety Document issued by a Senior
Authorised Person

7. General Requirements
•When work or testing is to be carried out on Apparatus
which is in proximity to exposed HV Apparatus which
may be Live, or become Live, the relevant
requirements of Safety Rules Procedure
KC-PR-SAF-006, ’Demarcation ofWorkAreas in Sub-
stations’,
must be met and an appropriate Safety Document
issued by a Senior Authorised Person.

8. General Requirements
•When work or testing on Apparatus requires portable
instruments to be used for voltage or resistance
measurements on circuits, the instruments or leads
must be provided with protection to safeguard persons
from Danger.

9. Work orTesting on Isolated Apparatus
•LV isolation should be by the withdrawal of fuse links
or other Isolating Devices.
•Where isolation is by the operation of HV Apparatus,
the isolation must be done in accordance with the
appropriate Safety Rules and Safety Rules Procedure
KC-PR-SAF-001, ‘HighVoltage Switching’.
NOTE that; switches, thermostats and other automatic
switching devices are not Isolating Devices.

10. Work orTesting on Isolated Apparatus
•Where reasonably practical, all points of isolation
should be Locked.
•If this is not reasonably practicable, the fuse links or
other Isolating Devices should be removed and
Caution Notices shall be affixed at all points of
isolation.

11. Work or testing on isolated apparatus
•Where work or testing is to be done on portable or
hand-held Apparatus, isolation may be achieved by
the removal of the plug from the socket outlet
provided that,
the plug remains in sight of the Person doing the work
or testing or the plug has a lockable device applied to it
which prevents it being inserted into a socket outlet.

12. Work or testing on isolated apparatus
•Where it is reasonably practicable for the Apparatus to
remain Isolated throughout the course of the work or
testing and the Senior Authorised Person has decided
to issue a Permit for Work, the associated Safety Keys
must be locked and the lock bar key issued with the
Permit for Work.

13. Work orTesting on Isolated Apparatus
•Where it is not reasonably practical for the Apparatus
to remain Isolated throughout the course of the work
or testing, the Senior Authorised Person may issue
the removable means of isolation and/or Safety Keys
to the Competent Person who is to do the work.
•The Competent Person must keep these in safe
custody, preferably by retaining them in his personal
possession, except when the Apparatus is made Live

14. Work orTesting on Isolated Apparatus
•Where the isolation is done by the Competent Person
who is also to carry out the work or testing, whether or
not a Limited Work Certificate is issued, he must take
any removable Isolating Devices and/or Safety Keys
into safe custody, preferably by retaining them in his
personal possession.

15. Work orTesting on Isolated Apparatus
•Where work or testing is to be continued by another
Competent Person, the Competent Person who was
doing the work or testing must surrender any
removable Isolating Devices and Safety Keys held in
his custody to a Senior Authorised Person.
•The Senior Authorised Person must retain them in
safe custody until he reissues them to the Competent
Person who is to continue the work or testing.

16. Work orTesting on Isolated Apparatus
•In order to facilitate the handing over of Isolating
Devices and Safety Keys, they must be readily
identifiable with the Limited Work Certificate or with
the Apparatus with which they are associated.

17. Work orTesting on Isolated Apparatus
• Where adjacent exposed Live Apparatus is present which
gives rise to Danger, work or testing must only be done by a
Competent Person who has completed an appropriate
course of training.
• Persons in Charge of Work must:
Where practicable screen off any adjacent exposed or
unprotected Apparatus which may be considered to be Live

18. Work orTesting on Isolated Apparatus
•Where necessary to prevent injury, use Approved
insulated tools, stands, mats, insulating gloves or other
personal protective equipment as appropriate, and
remove metallic objects from the hands and wrists.
•In addition consideration should be given to the
Competent Person being accompanied by another
Competent Person if his presence could contribute
significantly to ensuring that injury is prevented. Any
accompanying Competent Person should be trained
to recognise Danger and if necessary to render
assistance in the event of an emergency.

19. Work orTesting on Isolated Apparatus
•Before work or testing commences the Competent
Person who is to do the work or testing must check, by
means of an Approved voltage testing device, that the
Apparatus on which he is to work or test is not Live.
•The instrument used should be tested immediately
before and after use.

20. Work orTesting on Isolated Apparatus
•If work or testing is interrupted the Competent Person
who is to continue the work or testing must repeat the
procedure to check the testing device.
•Before work or testing is commenced on exposed LV
overhead conductors which have been Isolated they
must be proved not to be Live at the point of work by
the use of anApproved voltage testing device.The
conductors, including the neutral, must be short-
circuited and, where reasonably practicable, Earthed.

21. Work orTesting on Live Apparatus
• Work or testing may be done with the Apparatus Live
under the following conditions:
•The work must only be done by a Competent Person
who has been appropriately trained.
•The Competent Person who is to do the work should
first remove any metallic objects from his body.

22. Work orTesting on Live Apparatus
•All adjacent metal which is electrically bonded to earth
or conductors which are at a different potential to that
on which work is to be carried out must be screened with
insulating material to avoid Danger.The material used
for screening must be of sufficient strength to withstand
an accidental blow from a tool without tearing or
otherwise ceasing to be effective.

23. Work orTesting on Live Apparatus
•Before commencing work in ducts, trenches or
underground distribution boxes, where there is a
possibility of the presence of gas which might be
inadvertently ignited by electric sparks, a Selected
Persons report should be obtained and such special
precautions taken as are necessary to prevent such
Danger.

24. THANKS FORYOUR
PARTICIPATION
AND
HAVE A SAFE AND
FRUITFUL DAY