Surge Protection - Highway Electrical Association · 5 Fundamentals of Surge protection and main...

SURGE PROTECTION

Mark GriffinSurge Protection Solution Engineer UK

Pep SolerSurge Protection Marketing Manager

North Europe, Oceania, LATAM.

FUNDAMENTALS AND SOLUTIONS FOR

STREET & ROAD LIGHTING

Fundamentals of Surge protection and main applications2

1. Why protect LED street lighting / MERSEN experience

2. Introduction to surge protection & the operation of Surge

Protection Device (SPD)

3. SPD features based on the Standard IEC 61643

4. Typical Current (Ityp), beyond the Standard

5. BS 7671: 2018 / 18TH edition

6. SPD placement. LED street lighting application (BS7671 /18th Ed. Section 534.4 “Selection and installation of SPDs)

• Where and how to start?

• Cascading concept

7. Testing experience

TOPICS OF SURGE PROTECTION







5. BS 7671: 2018 / 18TH edition







WHY PROTECT LED STREET LIGTHING?

• « Outdoor » installation is highly exposed to weather and other perturbances.

• A more sensible technology to electric perturbances.

• Safety and continuity of service are key in public lighting.

➢ With a reasonable investment we can:

✓ Maximize life time of equipment

✓ Minimize cost of maintenance.


Inputs of LED market.

- Suppliers and final users take into account that LED Technology faces

some issues with overvoltage's in new installations.

- Main manufacturers of Fuse boxes have started integrating an SPD beside the fuseholder.

- Municipalities start making the surge protection mandatory (fuse box, luminaire) for their

street lighting LED installations.

- Even though some components in the luminaire are self-protected against overvoltage's; these

systems are not enough against lightning surges. Consequently many LED luminaire

manufacturers already integrate an SPD before the driver.

They prescribe protection in order to extend the warranty of the luminaire (panel, pole fuse box…)

- Maintenance savings: An SPD is 4 times cheaper than the driver of the luminaire.

When the protection gets to end-of-life, it needs to be replaced.


MERSEN experience

A common work of development has been together with Philips, and now they prescribe our

solution for street lighting in a white paper that is published on the Philips website.

White paper – Street

Lightning Philips

http://www.lighting.philips.com/b-dam/b2b-li/en_AA/support/product-support/White%20paper_The%20challenges%20of%20surge%20protection.pdf







5. BS 7671: 2018 / 18TH edition







Transient overvoltages are voltage surges that can reach tens of kilovolts with a duration of

the order of microseconds.

The energy content can cause:

• premature aging of electronic components.

• Equipment failure.

• Disruptions to service and financial loss.

WHAT ARE OVERVOLTAGE SURGE?

ARE THESE KA

COMPARABLE

TO POWER

FREQUENCY KA

(50 HZ)?


ORIGIN OF OVERVOLTAGES

Current wave 10/350

Conduction

Current wave 8/20Comparison 10/350 vs 8/20

S2: Induced overvoltage

S4: Induced overvoltage on the power supply lines

S0: Switching based overvoltage

S1: Direct impact of lightning in luminaire.

S3: Direct impact on power line.

Induction

MAIN SOURCE

OF SURGE!!!


HOW SPDS WORK?

Normal voltage = Very high resistance

Over voltage = Low Resistance

= High through current

10kA In(20kA) Imax(40kA)1kA

SPD real behavior – uncertainty

region


8 kV

4 kV

Oudoor LED luminaire robustness:• Some components in the luminaire are self-protected against overvoltages, but this is not

enough against lightning surges. Standards recommend 6-10 kV protection.

• It is a must that external SPDs have to coordinate with these internal elements to

guarantee the protection.

4 kV

8 kV

10 kV

ROBUSTNESS CLASSIFICATION / NEED OF COORDINATIONFOR ELECTRIC & ELECTRONIC DEVICES







5. BS 7671: 2018 / 18TH edition







KEY SURGE PARAMETERS

The following are the most crucial in terms of application and

technical feature comparison:

• Robustness:

• Nominal current (In)

• Maximum current (Imax)

• Impulse current (Iimp)

• Protection level/rating (Up or VPR)

• Installation features:• Maximum continuous operation voltage (Uc)

• Number of poles

• Remote indication

• Common mode & differential mode

• …

THESE

CLASSIFY

SPD TYPES


IEC 61643 MAIN SPD CHARACTERISTICS

1- Robustness:

Iimp Maximum current the SPD is able to

withstand 1 time in 10/350

Imax Maximum current the SPD is able to

withstand 1 time in 8/20

In Maximum 8/20 peak current the SPD is

able to withstand around 20 times


SPD CLASSIFICATION ACCORDING TO IEC-61643-11 STANDARD


MAIN SPD CHARACTERISTICS

2- Level of

protection:Up Residual voltage between terminals after a

nominal current discharge (only for IEC 61643.1)

UcMaximum continuous operation voltage can be

applied permanently to the terminals of the

protection device

Others… Number of poles, configuration, remote

indication…

3- Where to

install:







5. BS 7671: 2018 / 18TH edition







Typical Current (Ityp), beyond the Standard

1- Robustness:

The Iimp/Imax and In show the robustness of the SPD, but the real surge currents

are lower.

The Typical Surge Current (Ityp) is the value that statistically the SPD faces in

real life. The value depends on the level of exposure:

Ityp Typical surge current

HIGH EXPOSED

LOCATIONS:

LOW EXPOSED LOCATIONS OR

SWITCHING SURGES:

Ityp = 20kA 8/20 Ityp = 5kA 8/20


MAIN SPD Characteristics

Robustness:

To estimate the lifetime of the SPD is a must in order to guarantee the protection.

The SPD must be designed in order to pass the test of the standards, but

furthermore to guarantee a great performance in real life.

THE LIFETIME IS DESCRIBED WITH THE NUMBER OF HITS that the SPD is able

to withstand at Typical Surge Current (Ityp).

The minimum lifetime values that we must ask for are:

• HIGH EXPOSED LOCATIONS: 100-200 peaks

• LOW EXPOSED LOCATIONS OR INTERNAL SURGES: 500 peaks

It is important to highlight that in an electrical storm there are hundreds/Thousands of strikes.

The most common surges still come from the switching devices of the installations.

Life time of the SPDs







5. BS 7671: 2018 / 18TH edition







MAIN SPD Characteristics

BS 7671: 2018 / 18TH Edition

The 18th Edition opens the need for installing surge protection in a very broad spectrum from

public, commercial or industrial activities to, even consumer unit applications depending on

the circumstances.

A step ahead for surge protection:

Where is surge protection required?

Section 443. Protection against transient overvoltages of atmospheric origin or due to

Switching states that protection against transient overvoltages shall be provided where the

consequence caused by overvoltages could:

▪ Result in serious injury to or loss of, human life, or

▪ Result in interruption of public services and/or damage to cultural heritage or,

▪ Result in interruption of commercial or industrial activity, or

▪ Affect a large number of co-located individuals.







5. BS 7671: 2018 / 18TH edition







SELECTING A SURGE DIVERTER, HOW AND WHERE TO START

THE PROTECTION DESIGN? (BS7671 /18TH ED. SECTION 534.4 “SELECTION AND

INSTALLATION OF SPDS)

Feeder pillar


≤ 25kA (In) 100kA (Imax)

Ue: 6 kV

BUT…HOW CAN WE

PROTECT IN THESE

CASES?

CASCADING

METHOD!

SELECTION OF SURGE PROTECTION DEVICE

ZONE OF

PROTECTION

100kA (>Imax)


1Street lighting panel2 Mast

LED Street lighting application CASCADING METHOD

3 Luminaire


LED Street lighting application

LuminaireType 1+2 Iimp:12,5kA

Panel

STM SLIM FB

Fuse-box

Luminaire

1

2

3

First an initial protection stage should

be installed in the lighting panel with

the installation of a sturdy protector

with the duty to discharge the energy.

The remaining overvoltage has to be

reduced/limited by the following stage

Afterwards a 2nd stage of protection should be

installed as close as possible to the luminaire

providing fine protection to complement the first

stage

1

2

CASCADING METHOD

STPT12-12,5

Type 2+3 Imax: 10 kA


1

Solutions of protection

STPT12-12,5 STPT12-12,5

Type 1

tests

Peak

current

Number

of tests

12,5kA (L-N)

50kA (N-PE)

1 (Iimp)

Type 2

tests

65kA (L-N)

65kA (N-PE)

1 (Imax)

20kA (L-N)

50kA (N-PE)

20 (In)

20kA (L-N)

20kA (N-PE)

100

200

Street lighting panel:

Type 1+2 Iimp:12,5kA


Fuse box SPD:

2

• Second step of protection

• SPD Type C+D Imax up to 10kA

• Ultra-compact

• Disconnection with end-of-life

Status indicator

• TT, TN,

• Series or Parallel connection

2

2

Solutions of protection

2STM SLIM FB

Type 2+3 Imax: 10 kA


SPDs in the pole can be connected in two ways:

Series:

Priority is protection, if an SPD reaches end-of-life, the luminaire is disconnected.

Parallel:

Priority is continuity of service, if an SPD reaches end-of-life, visual indication of SPD becomes

red but the luminaire remains on.

Priority is

protection

Series or parallel connection

Priority is

continuity of

service







5. BS 7671: 2018 / 18TH edition







STM SLIM FB Lab tests description.

10 meters of wire

Luminaire 1: SCHREDER 1 nos AMPERAMAXI 128

LED 5700K 5518/198w + PHILIPS XI LP 150W 0,2-0,7A

+ SPD VOOSLOH SPC3/230/10K

Luminaire 2: AEC Iluminazione, Italo 1 Basic 0R3,

STE-S 4,7-4M, 107W, IP66, 1-10V Dimmable driver

PHILIPS XI LP 75W 0,2-0,7A + SPD PHILIPS

EXX166001000

Luminaire 3: SCHREDER 1 nos AMPERAMAXI 112

LED 5103K 5103/174w + PHILIPS XI LP 150W 0,2-0,7A

+ SPD PHILIPS EXX166001000

Test Description:

Three sample LED luminaires were tested at the independent “Lightning

Research Institute of Catalonia” to IEC 62475 – High Current Test

Techniques.

Part of this testing involves the sample LED’s having to withstand 15

impulses in 8/20 waveform at 5kA (declared as nominal current by the

manufacturer).

The Mersen SPD was fitted within the TOFCO Cut-Out Unit and wired up

to the LED lantern.


STM SLIM FB Lab tests description.


STM SLIM FB Lab tests results & conclusions.

1- All the samples have withstood the 15 impulses and worked properly after testing.

2- 94% of the surge current was clamped and discharged to earth via the Cut-Out SPD, this

assures that there is coordination between the Cut-Out SPD and the LED SPD, preventing

damage to the electronic driver and luminaire.

Results:

Conclusions:

1- The installation of the additional SPD unit in the Cut-Out provided the protection required to

protect the LED luminaire.

2- Advantage of using the above SPD solution:

• LED is protected and better guaranteed.

• Life of LED increased.

• Maintenance is reduced and the need to visit site to replace damaged SPD within the

luminaire is removed, saving on time and traffic management costs.

• Any maintenance issues are at the base of the lighting pole, instead of at high level

requiring road closure.

• In the event of “end of life” of the cut-out SPD unit, the power to the LED lantern is

disconnected as it is wired in series, again protecting the LED.

• The condition of the SPD can be visually checked through the cut-out window, if the

green indicator is on the SPD is operational, if the LED is off, the SPD had done its job

and requires replacing.

• Cut-Out unit is tested to IP54 & fully insulated.

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