National Wiring Rules for HV
Installations
Engineers Ireland 20.03.2014
Cormac Madden and Michael O’Hara TC3
Agenda
• Opening - John McAuley
• ETCI
• National Wiring Rules for HV
Installations
• Implications
• Next Steps
2
Electro-Technical Council of Ireland
Limited (ETCI)
• Voluntary body formally constituted in 1972
• 18 organisations representative of electro-technology in
the RoI
• NSAI is the Irish Member of:
– the International Electrotechnical Commission (IEC)
– the European Committee for Electro-Technical
Standardisation (CENELEC)
• ETCI is the electrical committee within this structure
3
ETCI Publications
4
Scope
• Installations exceeding 1 kV a.c/1,5 kV
d.c.
– Design requirements
– Selection
– Erection/Installation to ensure
• safety of persons
• proper operation
5
Scope (contd.)
• Exclusions:
– Factory-built and type tested equipment
– Type-tested equipment
– UG or OH lines between separate
installations
• Associated EU/International Committees:
– CENELEC CLC TC 99X
– IEC TC99
6
TC3 Members
Ciaran Allen
Consultant
Ian Cowan
NSAI
Philip Hicks
Hivar Engineering Ltd.
Martin Keane
ABB
Iarla Moran
Mayo Co. Co.
Michael O’Hara
O’Hara Engineering
Padraig Plunkett
Kirby Group
Pat Rathbourne
HVSM
Seamus Walsh
ESBI
Paul Moran (sec.)
EirGrid
Cormac Madden (chair)
ESB
7
Growth in MV and HV Installations
2007
2005
2009
Year
2003
2001
1,600
1,400
1,200
1,000
800
600
400
200
0
1999
Customers
MV and HV Customer Numbers
110kV TSO
110kV Network
38kV
MV
8
The Wiring Rules
Format of Wiring Rules
• Based on IEC Standard I.S. EN 61936-1
• Additional, national Requirements
National
requirements
are highlighted
in shaded
sections
10
Scope
Overview of Rules
Normative References
Terms and Definitions
Fundamental Requirements
Insulation
Equipment
Installation
Safety Measures
Protection, Control and Auxiliary Systems
Earthing Systems
Inspection and Testing
Operation and Maintenance
11
Overview of Rules
Scope
Normative References
Terms and Definitions
Fundamental Requirements
Insulation
Equipment
Installation
Safety Measures
Protection, Control and Auxiliary Systems
Earthing Systems
Inspection and Testing
Operation and Maintenance
12
Scope
Normative References
Terms and Definitions
Fundamental Requirements
Insulation
Equipment
Installation
Safety Measures
Protection, Control and Auxiliary Systems
Earthing Systems
Inspection and Testing
Operation and Maintenance
13
Scope
Preliminaries
Normative References
Terms and Definitions
Fundamental Requirements
Insulation
Equipment
Installation
Safety Measures
Protection, Control and Auxiliary Systems
Earthing Systems
Inspection and Testing
Operation and Maintenance
14
Scope
Design, Equipment
and Installation
Normative References
Terms and Definitions
Fundamental Requirements
Insulation
Equipment
Installation
Safety Measures
Protection, Control and Auxiliary Systems
Earthing Systems
Inspection and Testing
Operation and Maintenance
15
4: Fundamental Requirements
Voltage Class
Current
Rating
of Installation
Design
to take
account of:
Normal
Short Circuit
Frequency
Corona
Overvoltages
Harmonics
Note Distribution Code Requirements
Mechanical
Environmental
Special
Maximum operating voltages
Requirements for selection of equipment for Climatic and environmental
conditions both indoor and outdoor are addressed in section 4.
16
5:
Insulation
5: Insulation
Selecting Insulation Level
Highest voltage of installation
Impulse withstand voltage
Neutral earthing method
Environment
Distribution Code Requirements
Basic insulation levels
Clearance distances for 10kV, 20kV and 38kV
17
Table 1 – Minimum clearances in air – Voltage range I (1 kV < Um ≤ 245 kV)
The Distribution Code
requires 125 kV for all
these in Ireland
180 mm in Ireland
220 mm in Ireland
18
5:
Insulation
5: Insulation
Change in the Distribution System: Implications for existing installations
Moving to an unearthed 10 kV system
Earth fault protection
BIL of equipment
Overvoltages in event of arcing earth fault
Phase voltages
Insulation and clearances
Increase in prospective short circuit levels
In particular on the 10 kV system
Care in equipment selection
19
6:
Equipment
• Instrument transformers:
–
–
–
–
–
–
Protection class
Measurement class
Ratio
Safety Factor
Accuracy Limit Factor (ALF)
Burden
• Protection
– Sensitive Earth Fault (SEF) protection:
• Directional is recommended
– Directional SEF:
• monitoring of the secondary voltage of voltage transformers is crucial
• loss of the residual voltage effectively disables the SEF
• Loss of secondary voltage to directional SEF ideally should initiate other
earth fault protection using parameter change over or similar.
20
6:
Equipment
• Switchgear
– Indication of position of primary contacts
• Unambiguous
• Clearly visible
– Earth switch locking facilities at the point of
connection to the Distribution System
– Transformers and reactors
• includes protection of the environment if loss of
insulating fluid
21
6:
Equipment
• Cables:
– “Code of Practice for avoiding danger from
Underground Services” from HSA
– Installation of single core cables set out
– Installation in unstable ground such as bog
land
• Ground movement may put pressure on cable
terminations, bushings etc.
22
8:
Safety Measures
• This section covers measures for protection in respect of :
–
–
–
–
–
–
•
•
•
•
direct contact
Indirect contact
Persons working on electrical installations
Arc fault
Lightning strokes
Fire
Devices to prevent reclosing of isolating devices
Devices for determining the de-energized state
Devices for earthing and short-circuiting
Protection against leakage of insulating liquid and SF6
Together with the requirements of IE EN50110 is
the basis for safe operation of HV electrical installations
23
9:
Protection
• This section covers:
– Protection, overcurrent, Earth Fault etc.
– DC and AC Supply Circuits
– Compressed Air Systems
– SF6 Gas Handling Plants
– Hydrogen Handling Plants
– EMC of control systems
– Measures to reduce the effects of high and low
frequency interference
24
9:
Protection
• DC Supply Unit Batteries must be sized to:
– trip breakers and switches at the start of a discharge
period
– supply any continuous DC load
– close the elements of the installation that will restore
a.c. services
25
10:
•
Earthing
This section covers:
–
–
–
–
Design
Installation
Testing
Maintenance
•
of earthing systems.
•
Main points:
– The requirements are designed to address the possibility of a current flowing
through a human being
– based on a probabilistic curve for touch voltage
– In general, interconnection of HV and LV earths is recommended
– The HV earthing system shall form part of the lightning protection system
•
•
This section should be read in conjunction with the Low Voltage National
Rules in particular Section 442.
This section also sets out touch voltage and stress voltage limits arising
from Earth Potential Rise (EPR)
26
Permissible touch voltage UTp
Scope
Commissioning and
Maintenance
Normative References
Terms and Definitions
Fundamental Requirements
Insulation
Equipment
Installations
Safety Measures
Protection, Control and Auxiliary Systems
Earthing Systems
Inspection and Testing
Operation and Maintenance
28
11: Inspection and Testing
•
This section covers:
–
Inspection and tests to verify:
•
•
•
compliance of the installation with the rules
Compliance of the equipment with the applicable technical specifications
Main points
–
Description of verification by:
•
•
•
–
Visual inspection
Functional tests
Measuring
Completion certificate with generator supplement
•
These tests must be carried out by a competent person as described in IS EN 5110.
•
The following must be available to the person carrying out the inspection
–
–
–
–
Detailed Drawings and specification for the installation
Fault levels at the point of supply
Details of the supply system earthing (Earthed or Unearthed)
The necessary test equipment to carry out the tests set out in this section.
29
11: Inspection and Testing
• Note: setting and testing of protection systems:
– the settings issued by SO are the maximum settings
required to discriminate with the public system
– May not:
• adequately protect a consumer’s installation
• satisfy the requirements of these Rules
• Satisfy the requirements of the HSA
– In particular Earth Fault and Short Circuit Settings.
• Also true of synchronising generator protection
settings [check TSO]
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Completion Certificate Layout 1
Part A: Installation ( < = 38kV ).
Grid
Ref.
MPRN:
N
W
Site
Details
Substation
Name:
Customer
Name:
Company
Installation
Name &
Address:
Postcode:
Certificate in respect of:
Construction & Test of Installation:
or Test only of existing installation:
Date:
/
/
Type:
New
Alteration
Test only
31
Completion Certificate Layout 2
Connection ratings:
Connection Voltage
Max. Import capacity
kV
Site Fault Level
Min. I’’k3 1
Min. I’’k1 2
MVA
kVA
kA
kA
Max. Current
Max. Export capacity
kA
Site Generation capacity
Max. I’’k3 1
Max. I’’k1 2
kVA
kVA
Connection
Ratings
kA
kA
Supply System Neutral arrangement
Resistance of Earthing system
1
2
3 phase fault currents
Line to Earth Fault Currents
32
Completion Certificate Layout 3
Protection Settings & Tests (Directly connected Equipment):
Settings
Received from
DSO:
Protection Type:
Earth Fault:
Sensitive Earth
Fault.
Overcurrent.
On Site Settings:
Relay has
agreed
settings
implemente
d.
Confirmed
Relay
injected &
functionally
tested.
Relay
ripping
circuit
verified.
Confirmed
Confirmed
Earth Fault.
Sensitive Earth
Fault.
Overcurrent.
Refer to Protection Report
(Please include report references)
33
Completion Certificate Layout 4
Alarms & Signalling:
All protection alarms and signals verified

Yes
Equipment Type &
Label.
(e.g. switchgear,
transformer,
generators, cable,
surge arrestors)
Ratings (as applicable)
kV
A
MVA
Short
cct.
Cable
BIL
(kV)
Test Sheets
attached:
Quantity
Connected Equipment Details:
Length Size
(m)
(mm2)
(kA)
34
Completion Certificate Layout 5
Verifications
Main Compound
Other locations
Yes
Yes
(tick boxes as appropriate)
Equi-potential Bonding
Earth Electrode
Resistance Measurement
Verifications
Tolerable EPR limits not
exceeded and verified by
current injection.
Switchgear Compliant
Interlocks Operational
Facility to Lock Earths
DC supplies
Protection Operation
Protection Trips verified
Cables
Access & Egress control
Cleanliness & Tidiness
General
Environmental
(Other as applicable)
(Other as applicable)
(Other as applicable)
(Other as applicable)
35
Completion Certificate Layout 6
Contractor:
Reg no:
Name:
Tel:
Certification
Address
All necessary commissioning tests
completed and satisfactory.
Signed:
Date:
Designer:
Name:
Signed:
Date:
Yes
(tick box)
36
Steps followed
Since we last met….
February 2011
Consultation Opens
May 2012
Consultation Closes:
8 submissions
212 questions
November 2013
Conclusion
December 2013
Completion
Next steps….
Jan – Mar 2014
Prepare for publication
May 2014 est
Publication of 1st
edition
June/Sept 2014
Communication
October 2014 -
Maintenance
Questions
38
Thank You
ETCI, Unit H12, Centrepoint Business Park, Oak Road, Dublin 12.
Tel: 01-4290088
email: info@etci.ie
www.etci.ie
ETCI Objectives
• Promote and co-ordinate standardisation in all branches
of electro-technology
– in harmony with international agreements
– in collaboration with the National Standards Authority of Ireland
(NSAI).
• Liaison with similar bodies in other countries and with
international bodies.
• Promote safety in electrical equipment and installations
• Awareness of electrical safety among the general public
• Advise and make recommendations on any matter
pertaining to electrotechnology
– subject to the statutory powers, duties and functions of other
bodies.
40
Structure of ETCI
41
REFERENCE SLIDES
42
12: Maintenance Manual
• Each installation shall have:
– An operation manual
• Procedures: Normal, emergency and maintenance
• Safety instructions for operation of HV installation
– A set of up-to-date drawings and diagrams on
premises
– Manufacturers’ operation and maintenance manuals
– Visible display of emergency routes to nearest
hospital and emergency phone numbers
43