Arc flashes in switchgear and drives imply:

1. the risk of injury to site personnel, as well as

2. damage to the affected equipment.

• Switchgear offers “passive” arc mitigation solutions (safety by design, defined by standards) and on top of that “active” arc mitigation technologies.

• But also MV Drives have solutions at the forefront of arc flash safety (ABB MV Drives have defined 4 classes for arc fault protection)

This presentation outlines the different steps and how they make a difference.

Summary

Arc Flash Detection and Mitigation

February 18, 2017 Slide 1

GAS/ELECTRIC PARTNERSHIP CONFERENCE, HOUSTON, FEB. 9TH 2017

Arc Flash Detection and MitigationTanner Knecht, Project Proposals Manager, ABB Drives and Controls, MV and High Power Drives

Thomas Schmidtchen, Global Oil and Gas Segment Manager, ABB MV Electrification Products

Passive arc mitigation – safety by design

Arc Flash Detection and Mitigation

February 18, 2017 Slide 3

Pressure relief plenums integrated in the switchgear design

Arc resistant switchgear

Passive arc mitigation – safety by design

Arc Flash Detection and Mitigation

February 18, 2017 Slide 4

Maximized personnel safety

Non-arc resistant switchgear Arc resistant switchgear

Active arc mitigation

Arc Flash Detection and Mitigation

February 18, 2017 Slide 5

Multiple solutions for highest personnel and equipment safety

Mechanical microswitches(on pressure relief flaps)

Optical sensors and CTs(flash + current = trip)

ABB’s UFES™(Ultra-fast Earthing Switch)

A B C

Arc cleared in 70... 90ms Arc cleared in 60... 90ms Arc cleared in <4ms

Active arc mitigation via Ultra-fast earthing switch (UFES)

Arc Flash Detection and Mitigation

February 18, 2017 Slide 6

W/o grounding switch (arc duration 100ms) With grounding switch (arc duration <4ms)

Medium Voltage Drives

Arc Flash Detection and Mitigation

February 18, 2017 Slide 7

IEC

NEMA

Switchgear Power Electronic Converters Drives

IEC 61800-5-1 Safety requirements, Electrical, thermal and energy

IEC 62271-200 High-voltage switchgear and controlgear

IEC 62477-2 Safety requirements for power electronic converter systems and equipment

IEEE C37.20.7 IEEE Guide to test metal-enclosed switchgear

nonIEC 61800-5-1 Safety requirements, Electrical, thermal and energy

UL UL347 (a) Medium Voltage Power Conversion Controllers

UL347Medium-Voltage AC Contactors, Controllers, and Control Centers

none

This are most relevant standards for

MV (and LV) drives safety

requirements.

Future revision will reference to

IEC62477 (-1 for LV) and (-2 for MV)

for arc resistant design

Presently there is no relevant standard

released for arc resistant design of

MV drives.

ABB and other companies have applied

switch gear standards.

IEC and IEEE are very similar

A new IEC standard relevant for MV drives will

be released soon (IEC62477-2)

This standard will be relevant in IEC world and

likely also in NEMA world

The standard allows to reuse the certifications

according switchgear standards

Standards witharc resistant design requirements

Standards withoutarc resistant design requirements

Medium Voltage Drives

Arc Flash Detection and Mitigation

February 18, 2017 Slide 8

Class I - protection based on arc prevention

• Design of insulation systems in accordance with relevant IEC and NEMA standards

• Class I is not an certified arc resistant design, it is mainly focusing of arc fault prevention.

Class II - protection based on cabinet structure

• The cabinet is designed to withstand the pressure of an arc flash

• Arc fault is contained in the cabinet or guided through pressure relief vents.

• The drive will be face severe damage after an event.

Class III - protection based on external arc fault limitation and elimination

• HV Fuses are applied externally to the drive in order to limit the arc fault current to less than half cycle of the fundamental AC frequency (< 10ms in case of 50Hz supply)

• This method is only used to reach arc resistant designs for MV drives connected without external drive transformer to the mains (integrated transformer solutions and DTL solutions).

Class IV - fast arc elimination

• This is a ABB patented method, which combines fast optical arc fault detection and ABB MV drives “protection firing” system. The arc fault is detected and converted into a non severe bolted short circuit within 4 – 8ms.

• Provides highest level of personal safety and the equipment remains undamaged and can be immediately restarted after inspection and elimination of the arc ignition cause.

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Medium Voltage Drives

Arc Flash Detection and Mitigation

February 18, 2017 Slide 9

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Product ABB class Rating

ACS1000a II IAC AFLR 5kA / 0.5s

ACS1000w II IAC AFLR 6kA / 0.5s

optional: 15kA / 0.5s

ACS2000 DFE IEC II IAC AFLR 15kA / 0.45s

IV IAC AFLR 18kA / 0.5s

ACS2000 AFE IEC II IAC AFLR 3.5kA / 0.5s

ACS5000a non

ACS5000w IV IAC AFLR 56kA / 0.5s

ACS6000 II IAC AFLR 20kA / 0.5s

IV IAC AFLR 50kA / 0.5s

LCI (w) II IAC AFLR 23kA / 0.5s