safety rules for working with hv electricity - idc … rules for working with hv electricity ... iec...

Safety Rules for Working with HV Electricity

Hans Slagter Technical Marketing Executive

DEHN + SÖHNE

HV Design & Installation Forum

Brisbane 2013

5 Safety rules and Standards

Voltage Detectors, standards, test methods,

interferences fields and maintenance

Live working – Portable Earthing and short-circuiting

devices

Safety Equipment

1.

2.

3.

4.

5.

1. Disconnect completely

2. Secure against re- connection

3. Verify that the installation is dead

4. Carry out earthing and short-circuiting

5. Provide protection against adjacent live parts

Five safety rules

Switching sticks

Fuse tongs

Insulating

blades

Lock-out

systems

Phase comparators

Distance voltage detectors Voltage indicators

Voltage detectors

Earthing and

short-circuiting devices

Ball pins

Earthing

cartridges

E+S kits

Connecting

elements

3. Verify the installation

is dead

4. Carry out earthing

and short-circuiting

Standards – Operation of electrical installations

Five safety rules

4.

3.

Standards concerning voltage detectors

IEC 61243 standards

IEC 61243-3

Live working –

Voltage detectors

Two-pole low-voltage type

IEC 61243-1

Live working –

Voltage detectors

Capacitive type to be used

for voltages exceeding 1 kV a.c.

IEC 61243-2

Live working –

Voltage detectors

Resistive type to be used for voltages of

1 kV to 36 kV a.c.

IEC 61243-5

Live working –

Voltage detectors

Voltage detecting systems (VDS)

AS 2067: 2008 - Substations and high voltage

installations exceeding 1 kV a.c.

6.4.4 Devices for determining the de-energized state

Devices for determining that equipment is no longer energized

shall be provided, where required, taking operational requirements

into consideration……………

All devices supplied shall permit the de-energized state to be

checked at all points where the work is to be done and that have

previously been live, without danger for the operational personnel.

Either fixed equipment or portable devices (see IEC 61243) can be

used to meet this requirement.

ENA: 2009 - National guideline for management of tools

and equipment used in the electricity supply industry.

3.7 High voltage detectors and phasing units

3.7.1 Scope

This section applies to portable devices used for proving high

voltage electrical apparatus energised or de-energised, or phasing of

circuits

3.7.2 References

There is no Australian Standard which specifically covers High

Voltage detectors

Related information may be found in the following standards:

• IEC 61243-1: Live working – Voltage detectors - Capacitive type

to be used for voltages exceeding 1 kV a.c.

• IEC 61243-2: Live working – Voltage detectors - Resistive type

to be used for voltages of 1 kV to 36 kV a.c.




3.7.1 Description/specification

High voltage detectors used on systems subject to induced

voltages (such as double-circuit lines carrying high load currents)

should be able to discriminate between induced voltage and

system voltage – to prove conductors de-energised even if some

induced voltage is present.

Practical Use

Voltage Detectors in accordance

with IEC 61243

Capacitive type to be used for voltages exceeding 1 kV a.c.

Type PHE

Practical use of voltage detectors

IEC 61243-1


IEC 61243-2/A2

PHE/G II d.c. voltage detector

for d.c. links (ICE power car)

Resistive type to be used for voltages

up to 24 kV d.c


IEC 61243-3

two-pole voltage detector

with extension prods

Design of Voltage Detectors


with IEC 61243

Voltage detectors acc. to IEC 61243-1 Design and

description of the individual parts

category L (line)

• Short test prod

• For overhead lines

category S (switch) • Long test prod

• For switchgear installations due to resistance to interference fields

• Also suited for overhead lines

separate type

must be attached to a suitably

rated insulating stick!

complete type

tested unit consisting of an

insulating stick, indicator and test

prod

Voltage detectors acc. to IEC 61243-1

Design and description of the individual parts

insulating clearance II

• Safety clearance

• Sufficient insulation

• Safe operation

hand guard

prevents slipping off or

contact with the

insulating element

handle

insulating clearance II

indicator

test prod with contact

electrode

• For distant parts of an installation

• For eliminating the influence of

interference fields

limit mark

red ring

Application of Voltage Detectors


with IEC 61243

Voltage detectors acc. to IEC 61243-1 Application

Absence of supply voltage

Must be verified on all poles at the work

location or as close as possible to the work

location

Electrically trained and skilled

persons only

Nominal voltage /

Nominal voltage range Only use voltage detectors for the

nominal voltage specified on the name

plate!

Risk of: Incorrect indication

Arcing

Electric shock


Application

Work environment

For indoor use only

For indoor installations and outdoor

switching stations, also suitable for

use in wet weather conditions (e.g.

rain, snow, fog or dew)


Functional test

With self-testing element

Before and after each

use!

Attach voltage detector to a part of the

installation under operating voltage

Without self-testing

element

• Press the “Test“ button

(approx. 3 sec.)

• Acoustic signal 77 dB

• Red light flashes 50 000

Lux Outdoor type (1 000

Lux indoor)

• Release button

• Permanent green light


with IEC 61243

Influence of Interference Fields

Influence of interference fields on voltage detectors

Effects without external voltage


Effects with external voltage

∆u < 10% U

∆u = U


Use in a phase opposition interference field

Different potential

in the coupling area!


Use in an in-phase interference field

Du = 0

category L category S

Influence of interference fields


with in-phase interference fields - Test set-up

category “S“

with extension

category “L“

without extension

Detector must be

removed from

service!




3.7.5 Tests – Acceptance

In addition to clause 2.2.1 for units that are not manufactured to a

recognised standard, the following tests should be performed to

ensure correct:

• Threshold voltage operation on all ranges – this could include

interference tests

• Visual and/or audible operation

• Operation of self test function

Pre-use - Prior to each use, the high voltage detector or phasing

unit shall be proved for correct operation. They shall also be

proved immediately after any “no indication” results


Calculation of the Threshold voltage range Ut in accordance with

IEC 61243-1

Sample calculation

UN = 20 kV (PHE3 20 S) 0.10 UN max < Ut ≤ 0.45 UN min

0.10 x 20 kV ≤ Ut ≤ 0.45 x 20 kV

2.0 kV ≤ Ut ≤ 9.0 kV

Possible range of Ut

0 kV 2.0 kV 9.0 kV

Sample calculation Switchable Type

UN = 11 ... 33 kV (PHE3 11 33 S) 0.10 UN max < Ut ≤ 0.45 UN min

0.10 x 33 kV ≤ Ut ≤ 0.45 x 11 kV

3.3 kV ≤ Ut ≤ 4.95 kV 0 kV 3.3 kV 4.95 kV


Calculation of the Threshold voltage range Ut


UN = 11 ... 33 kV (PHE3 11 33 S) 0.10 UN max < Ut ≤0.45 UN min

0.10 x 33 kV < Ut ≤ 0.45 x 11 kV

3.3 kV < Ut ≤ 4.95 kV 0 kV 3.3 kV 4.95 kV


UN = 11 ... 49.5 kV) 0.10 UN max < Ut ≤ 0.45 UN min

0.10 x 49.5 kV < Ut ≤ 0.45 x 11 kV

4.95 kV < Ut ≤ 4.95 kV 0 kV 4.95 kV

The ratio of 1:45

can not be exceeded!

Maintenance Test


with IEC 61243

Maintenance test acc. to IEC 61243-1

General test procedure and documentation

Voltage detectors are to be tested

for compliance with the limit

values specified in the

Electrotechnical rules

The test intervals depend on the

conditions of use, frequency of

use, environmental conditions and

transport. However, test have to

be carried out at least every

6 years!

Tests are documented in a test

report and on the voltage

detector.

Health and safety legislation is

mandatory!


Visual inspection, manual testing and measurements


Measurement of the leakage current

earth electrode high-voltage electrode

hs

hand guard

red ring

Hs Height of the insulating

element of the divider

insulator

Test shall be considered

passed if leakage current:

Dry ≤ 50µA

Wet ≤ 0.5 mA


Test for protection against bridging

bar A

bar B

Cu or Fe


Test for protection against bridging


Test for clear indication – Category S

UN

(kV)

ao (mm)

category “L“

ae (mm)

category “S“

H

(mm)

D

Ø (mm)

d

Ø (mm)

1 < UN ≥12

12 < UN ≥ 24

24 < UN ≥ 52

52 < UN ≥ 170

170 < UN ≥ 420

100

270

430

650

850

300

1000

> 1500

> 2500

550

1050

60

100

>H

ring electrode ball electrode

D d

ae

UN

(kV)

ao (mm)

category “L“

ae (mm)

category “S“

H

(mm)

D

Ø (mm)

d

Ø (mm)

1 < UN ≥ 12

12 < UN ≥ 24

24 < UN ≥ 12

52 < UN ≥ 170

170 < UN ≥ 420

100

270

430

650

850

300

1000

> 1500

> 2500

550

1050

60

100


Test for clear indication – Category L

>H

ball electrode ring electrode

D

ao

d


Test for clear indication – Category L


with IEC 61243

Marking of Voltage Detectors


Mandatory labels for indicators

• Manufacturer’s name or logo

• Symbol (double triangle)

• Nominal voltage and/or nominal voltage

ranges

• Nominal frequency and/or nominal

frequency ranges

• Type designation, production

number

• Category (S or L)

• Indication group

• Climatic category (C, N or W)

• Year of manufacture

• Date of the last maintenance test

• “Indoor“ or “outdoor“ use


with IEC 61243

Withdrawal from Use


Withdrawal from use

The following voltage detectors exceeding 1

kV do not comply with EN/IEC 61243-1

No extension

Incorrect indication in an

in-phase interference

field!

No insulating clearance or

no marking of the insulating

clearance (no red ring)

Risk of electric shock!

Indicator in the

handle section

Illegible

rating plate

d.c. Voltage Detectors in accordance

with IEC 61243-2

Design

d.c. voltage detectors acc. to IEC 61243-2

Design of the PHE/G I voltage detector up to 24 kV d.c.

plug-in coupling

for extending the handle

limit mark

orange ring on test prod

test prod

with positive pole

test prod

with negative pole

Voltage detector for

contact wires with

additional earth-side

magnetic contact

insulating

clearance II

Selection and Design of Portable

Earthing

Earthing and Short-Circuiting Devices

in accordance with IEC 61230



3.12 Portable earthing and protective bonding systems

3.12.2 References

There is NO Australian Standard which specifically covers portable

earthing systems. However IEC 61230: Live working – Portable

Equipment for Earthing or Earthing and Short-Circuiting is

considered the accepted industry reference.

ISSC14 Guide to electrical workers’ safety equipment

16 PORTABLE EARTHING SYSTEMS

16.2 References

There is no Australian Standard which specifically covers portable

earthing systems.

Related information may be found in the following standards:

• IEC 61230: Live working - Portable equipment for earthing

or earthing and short-circuiting

Ref: NSW Industry Steering Safety Committee, October 2010

Earthing and short-circuiting device


High-voltage and low-

voltage installations:

• Earth and short-circuit all

parts at the work location

• Connect earthing and short-

circuiting devices first to the

earthing system

• Earthing and short-circuiting

devices must be visible from

the all work location

Working procedure, General

Earthing and short-circuiting device in accordance with

IEC 61230

transformer station

high-voltage side

transformer station

low-voltage side


High-voltage side – Calculation of the cable cross-section

Max. short-circuit current IK

for a duration tK of

1 s 0.5 s Cross-section

29.6 kA

23.7 kA

18,7 kA

13.8 kA

9.9 kA

6.9 kA

42 kA

33.5 kA

26.5 kA

19.5 kA

14 kA

10 kA

150 mm2

120 mm2

95 mm2

70 mm2

50 mm2

35 mm2

Short-circuit power SK“

Short-circuit duration tK

Nominal voltage UN

IK“ = (UN • 3 )

SK“ Formula for calculating the

short-circuit current IK

IK“ =

20 kV • 3

500 MVA = 15.43 kA

required cable cross-section: 95 mm²

SK“ : 500 MVA

tK : 1s

UN : 20 kV

Sample calculation


High-voltage side – Cable cross-section table

Cable cross-section depending on the max. short-circuit current Ik and

the max. short-circuit time Tk and cable final temperature 250O C

10 s 5 s

Cross-section

of the copper

cable

1 000 A

1 600 A

2 200 A

3 100 A

4 400 A

5 900 A

7 500 A

9 400 A

1 400 A

2 200 A

3 100 A

4 400 A

6 200 A

8 400 A

10 600 A

13 200 A

16 mm2

25 mm2

35 mm2

50 mm2

70 mm2

95 mm2

120 mm2

150 mm2

2 s

2 200 A

3 500 A

4 900 A

7 000 A

9 800 A

13 200 A

16 700 A

20 900 A

1 s

3 200 A

4 900 A

6 900 A

9 900 A

13 800 A

18 700 A

23 700 A

29 600 A

0.5 s

4 500 A

7 000 A

10 000 A

14 000 A

19 500 A

26 500 A

33 500 A

42 000 A

Max. short-circuit current Ik over a duration of


Low-voltage side

100

3.61

25

125

4.51

25

160

5.77

35

200

7.22

50

250

9.02

50

315

11.37

70

400

14.43

95

500

18.04

95

630

22.73

120

800

23.09

120

1000

28.87

150

nominal power of the

transformer (kVA)

short-circuit

current IK (kA)

cable cross-

section (mm2)

Calculation of the

cable cross-section IK“ =

(UN • 3 ) • uz[%]

SK“ • 100 %

1250

36.08

*

1600

46.19

*

2000

57.74

*

UN Nominal voltage

IK Short-circuit current

uz Short-circuit voltage

for example,

SK: 630 kVA

tk: 1s

IK“ = (400 V• 3 ) • 4

630 kVA • 100 %

IK“ = 22.7 kA

UN: 400 V

uz: 4%

Note: The low-voltage side is mostly

solidly earthed. Thus, earthing and short-

circuiting devices must have the same

cable cross-section.

max. short-circuit current

Flat / round conductor


Selection and installation of ball pins

0.5 s 1 s Connection element

20 mm ball pin

25 mm ball pin

20

25

19.5 kA 13.8 kA

33.5 kA 23.7 kA

42 kA 29.6 kA *

* *

*

Installation of a ball pin as

connection point on a busbar

* only applies to straight ball pins from DEHN + SÖHNE

incorrect!

max. short-circuit current

Flat / round conductor


Selection and installation of ball pins

0.5 s 1 s Connection element

20 mm ball pin

25 mm ball pin

20

25

19.5 kA 13.8 kA

33.5 kA 23.7 kA

42 kA 29.6 kA *

* *

*

Testing of ball pins

* only applies to straight ball pins from DEHN + SÖHNE

Earthing and short-circuiting device in accordance with

IEC 61230

Earth connection

element

Phase connection

element

Connection to the

earthing system

1.

2. Connection to the parts

to be earthed.

Visible from the work

location. Otherwise as close

as possible to the work

location!

Reduction of the cross-

section in case of a

compensated earthed

system



Test currents and Markings

Test current - IEC 61230: Live working – Portable Equipment

for Earthing or Earthing and Short-Circuiting

• The a.c. component of the test current It shall be equal to 1,15 times the rated

current Ir ( It = 1,15 x Ir)

• The test first loop peak current Itm shall be not less than the a.c. component

of the test current multiplied by the peak current factor n ( Itm ≥ n x It )

Peak current factor n = 2.5 for 50 Hz and 2.6 for 60 Hz

Example: cable cross-section of 150 mm2, IK = 42 kA / 0.5 s

Itm ≥ n x It = 2.5 x 1.15 x 42 kA

Itm ≥ 120.75 kA

I tm

≥ n

x I

t

d.c. component of the current

Top envelope

Bottom envelope

Test current - IEC 61230: Live working – Portable

Equipment for Earthing or Earthing and Short-Circuiting

The earthing device itself or an additional non-removable label shall be

marked where appropriate with at least the following items of marking:

Manufacturer’s name or trade mark or assembler’s name;

Model or type reference for the device;

Year of manufacture;

Rated current Ir (kA), rate time tr (s) of the device and the value of the

rated peak factor n;

Number of the relevant IEC standard.

Markings

06.03.12/ 0000_E_1

Markings



Maintenance Test


Maintenance test

The employer must ensure that the

electrical installations and equipment is

checked for proper condition at regular

intervals.

The intervals must be chosen so that

the defects to be expected are detected

in time!

Occupational Health and safety

legislation is mandatory!

Earthing and short-circuiting device – Fatigue and

humidity penetration tests on cable with end fitting

60° 60°

10

axis of oscillation

cable guide to be tested

in the contacting cable

lug / connection element

copper cable

steel cable (6 mm)

Weight to obtain a resulting force =

0.5 N per mm2 of copper

Testing the efficiency of the

anti-kink sheath and the

corrosion resistance

01.07.2011 / 7059_E_1

1 000 cycles

Earthing and short-circuiting device – Tension test on

cable with end fittings

Each combination of cable to end fittings shall be tested using three test

samples – the force shall be applied for 30 sec.

Cross-sectional area

of conductor

Aa

mm2

Tension force

Copper

N

Tension force

Aluminium

N

≤ 50 100 x A 60 x A

≥ 50 80 x A 50 x A

a “A” = the rated cross-sectional area of the conductor

Example: 70 mm2 copper equates to a tension force N of : 80 x 70 = 5 600 N


Removal from service

No compliance with IEC 61230

Cable cannot be visually inspected

for black colouration!

Sheath prevents visual

inspection!

Reduction of the cross-

section due to copper

corrosion

Conclusion

• Work Health and Safety Regulation 2011 which came into force 1st

Jan. 2012 has far reaching implications for employers regarding

safety, training and the use of approved equipment.

• All 5 safety rules must be adhered to before work can commence –

there are no short-cuts.

• Only approved safety devices in accordance with recognised

international or local standards must be used. If no local standard

exists then only IEC standards should be adopted in line with

Standards Australia's policy on recognising and adopting

international standards

• All non approved products should be removed and quarantined!

• All employers have a duty to ensure that the employees are

adequately training and that approved safety equipment is made

available!

DEHN+SÖHNE GMBH + CO.KG

PO BOX 290,

South Melbourne, VIC 3205

Australia

TEL. +613 8414 8277

Suite 13, Level 4, 150 Albert Rd

South Melbourne

HANS SLAGTER

Marketing Executive Australia

eMail: [email protected]

www.dehn.com.au

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