12 easy steps to safe isolation
Step 1
Step 2
Step 3
Check with the duty holder/
authoriesd person that it is
acceptable to isolate the circuit/
equipment.
Ensure that there is a ‘Permit To Work’ in
place.
Identify the type of
supply system
TN-S – linked
main switch
TN-C-S – linked main
switch
TT – all pole Isolation –
All circuits and
equipment.
Serial No
Location
06 /
Front
– origi
nal
(Comple
te preci Permit-to
Part 1:
-work
sely an
Issue
d legibl
Issued
y in BL
to
OCK CA
I hereb ....................
PITALS
y
....
)
from all declare that it ....................
is
............
live co
nductor safe to work
............
on the
s and,
....
....
........
in the cas
fol
e of hig lowing electrica ....................
h volta
ge equip l equipment ....................
............
which
ment,
ha
....
is conn
ected to s been made ....................
dead, iso
.
earth:
lated
The sys
tem is
isolated
locks an and safety
d
signs fitt caution
ed at
All othe
r electri
cal eq
uipmen
t is da
ngerou
Danger
posted signs are
No
Identify suitable means
of isolation.
Other
pre
taken are cautions
The fol
lowing
wo
shall be
carried rk
out
Autho
rised Pe
rson
Signed
............
............
....
............
..........
Date ....
............
............
Locate and identify the circuit/
equipment to be isolated
including any alternative sources.
ork on
Step 7
Isolate circuit / equipment by:
• Switching off
- Double-Pole/
three-phase Isolator
- Circuit-Breakers
- Withdrawing fuse.
Step 4
s to w
The eq
uipment
earthe
is
d
locks fitt and safety
ed at
Step 8
Industrial and Commercial Installations
SATISFACTORY
............
............
HTM
06-02/
Step 6
Step 5
Verify the circuit/equipment
is functional.
Select an approved voltage
indicator device (GS 38)* this must
be verified.
• On a proving unit
(recommended)
If the circuit is not operational,
dead testing may be required
to verify the circuit.
Yes
03 PW
1 Ver 1.0
R
50 100 200 400
75 150 240 560
POWE
IT
G UN
VIN
PRO
690v
ge
t Volta
400v
Tes
230v
G
R
POWE
100v
IT
G UN
50 100 200 400
75 150 240 560
VIN
PRO
50v
690v
tage
400v
Vol
Test
230v
100v
50v
*GS 38 - 4th Edition. V1 CAT IV 2 pole VI conforms
to BS EN 61243-3
Step 9
Step 10
Step 11
Fit appropriate
lock off device
and locks.
Verify the circuit/equipment is
isolated. Use the approved voltage
indicator device to verify circuit is
dead. Test between all conductorsLine-Line, Line-Neutral, Line-Earth,
Neutral-Earth.
Re-check the approved voltage
indicator device is still functional
• On the same proving system as
Step 5.
Person carrying
out works to
retain key. Fit
warning label
for isolation and
identified work.
Issue permit to
work.
No
R
IT
G UN
VIN
PRO
690v
50 100 200 400
R
POWE
50 100 200 400
75 150 240 560
690v
Test
Vol
tage
75 150 240 560
IT
G UN
VIN
PRO
400v
230v
100v
No
SATISFACTORY
SATISFACTORY
POWE
G
Step 12
Test
ge
Volta
Yes
100v
50v
Always remain vigilant and recheck
with voltage indicating
device when
moving away and
returning to the
circuit/equipment.
R
POWE
400v
230v
Circuit/equipment should be safe
to carry out the work.
50 100 200 400
Yes
3 Phase = 10 tests
1 Phase = 3 tests
Process for re-energising the circuit/system
Step 2
Remove locking off devices, locks and labels and
restore electrical supply.
www.napit.org.uk
690v
Test
ge
Volta
400v
230v
100v
50v
50v
Step 1
After completing the work inspect and test in
accordance with Part 6 BS 7671 (dead tests).
IT
G UN
VIN
PRO
75 150 240 560
Step 3
Complete testing (live tests).
Commission circuit equipment.
0345 543 0330
Step 4
Complete and issue appropriate
test certificates/reports.