Download Background Statement for SEMI Draft Document #4773

Background Statement for SEMI Draft Document #4773
Line Item Revisions to SEMI S22, Safety Guideline for the Electrical
Design of Semiconductor Manufacturing Equipment
Revisions related to Short Circuit Current Ratings
NOTICE: This background statement is not part of the balloted item. It is provided solely to assist the recipient in
reaching an informed decision based on the rationale of the activity that preceded the creation of this document.
NOTICE: Recipients of this document are invited to submit, with their comments, notification of any relevant
patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this
context, “patented technology” is defined as technology for which a patent has issued or has been applied for. In the
latter case, only publicly available information on the contents of the patent application is to be provided.
NOTICE: The Safety Checklist for this document will be reviewed and voted on at the committee meeting where
the document is adjudicated.
Dear Colleagues,
Several industry standards require the electrical nameplate of an industrial control panel to include a short circuit
current rating (SCCR). For example:

NFPA 70-2008, Article 670.3
(A) - Permanent Nameplate. The nameplate shall include the following information:
(4) Short circuit current rating of the machine industrial control panel based on one of the following:
a. Short circuit current rating of a listed and labeled machine control enclosure or assembly
b. Short circuit current rating established utilizing an approved method.

NFPA 70-2008, Article 409.110 - Marking.
An industrial control panel shall be marked with the following information that is plainly visible after
installation:
(3) Short-circuit current rating of the industrial control panel based on one of the following:
a. Short circuit current rating of a listed and labeled machine control enclosure or assembly
b. Short circuit current rating established utilizing an approved method.

NFPA 79-2007, Section 16.4.1 - Machine Nameplate Data.
A nameplate giving the following information shall be attached to the enclosure:
(6) Short-circuit current rating of the control panel.

UL 508A, Industrial Control Panel, First Edition, April 25, 2001 (revised through May 1, 2003)
52.1 An industrial control panel shall be provided with a nameplate that includes the following:
b) Complete electrical rating of each source of supply as specified in 49.1
49.5 The input terminals in 49.1 shall have a short circuit current rating. The short circuit rating shall be
based on the requirements in Supplement SB. (Effective April 25, 2006).

SEMI S2-0709, Section 13.4.12 –
A permanent nameplate listing the manufacturer’s name, machine serial number, supply voltage, phase
frequency, short circuit current rating of the equipment or its industrial control panel and…

SEMI S22-0709, Section 20.4 i) – Equipment Nameplate –
A permanent nameplate should be attached to the main electrical enclosure or equipment where it is plainly
visible after installation. This nameplate should include the following information:
i) short-circuit current rating of the equipment or its industrial control panel…

IEC 60204-1 (2005), Clause 16.4 - Marking of equipment.
Equipment (for example controlgear assemblies) shall be legibly and durably marked in a way that is
plainly visible after the equipment is installed. A nameplate giving the following information shall be
attached to the enclosure adjacent to each incoming supply: ...
short-circuit rating of the equipment; …
i

IEC 60204-33 (2009), Clause 16.4 – Equipment nameplate.
A permanent nameplate should be attached to the main electrical enclosure of the fabrication equipment
where it is plainly visible after installation. This nameplate shall include the following information:
(i) short-circuit rating of the electrical equipment connected to each incoming supply.
These standards establish the requirement for an SCCR to be printed on the nameplate of a machine or its industrial
control panel, and for the SCCR to be established utilizing an approved method; however, the standards do not
establish what level of SCCR is acceptable, or not acceptable.
Since the introduction of these SCCR requirements, compliance with NFPA 70-2008, Article 110.10, has become
increasingly difficult. This code requires the SCCR of the circuit components to be selected to permit the circuitprotective devices to clear a fault without extensive damage to the electrical components of the circuit. This
presents a challenge for facilities engineers as the available fault currents at many semiconductor manufacturing
facilities exceed the SCCR rating of many pieces of semiconductor equipment. As a result, equipment installations
at facilities have been affected.
In an effort to help address this challenge, the semiconductor industry expressed an interest to develop and publish a
table containing a set of available fault currents, at various voltages and full load currents, at a ‘typical’ end-use
facility based on a set of ‘typical’ parameters. The goal of this table is to provide equipment suppliers and the endusers with a reasonable target values towards which to strive, both from the perspective of limiting the amount of
available fault current at the facilities level, as well as increasing the SCCR of the equipment or its industrial control
panel.
The table presented in this ballot is based on the available fault current calculations of a typical electrical
distribution system in a typical semiconductor manufacturing facility. The assumptions used and a graphical
representation of the typical facility and its 3-phase available fault currents are included in the proposed text,
The proposed RI includes a table that summarizes the typical maximum available fault currents in the described
facility.
This ballot consists of one Line Item for implementation to the referenced SEMI document. The Line Item
proposes including Table-1 in SEMI S22 as a means of documenting the available fault current at a typical facilities.
Equipment with a lower short circuit current rating than the available fault current may be prevented from being
installed at a facility.
This Line Item consists of two parts:
LI1, Part A:
Revise Note 12 in Section 5.1.66 of SEMI S22 to include reference to Related Information 3
suggesting ‘reasonable’ target values for facilities’ available fault current and short circuit current rating of
equipment or its industrial control panel.
LI1, Part B:
Add Related Information 3 to SEMI S22 with Table-1 Available Fault Current.
This ballot has not been prepared in Delayed Revision format and you are entitled to reject this Line Item based on
its effectivity being immediate upon publication, should it pass. Please also review the technical substance of this
Line Item. If you chose to reject this line item for any reason (i.e., effectivity or technical content), include in your
Reject vote (as required by SEMI regulations) any negative argument about the technical substance or effectivity
that you consider grounds for rejection.
ii
Review and Adjudication Information
Task Force Review
Short Circuit Current Rating Task Force
TBD (will be held during the week of
SEMICON West 2010: 12-16 July 2010)
Time & Timezone: TBD
San Francisco Marriott
Location:
City, State/Country: San Francisco, CA
Eric Sklar (Safety Guru, LLC)
Leader(s):
Group:
Date:
Standards Staff:
Ian McLeod (SEMI NA)
408.943.6996
[email protected]
Committee Adjudication
North America EHS Committee
Friday 16 July 2010
0800-1700 PDT
San Francisco Marriott
San Francisco, CA
Chris Evanston (Salus)
Sean Larsen (AMEC)
Eric Sklar (Safety Guru, LLC)
James Beasley
Ian McLeod (SEMI NA)
408.943.6996
[email protected]
This meeting’s details are subject to change, and additional review sessions may be scheduled if necessary. Contact
the task force leaders or Standards staff for confirmation.
Telephone and web information will be distributed to interested parties as the meeting date approaches. If you will
not be able to attend these meetings in person but would like to participate by telephone/web, please contact
Standards staff.
iii
Safety Checklist for SEMI Draft Document #4773
Line Item Revisions to SEMI S22, Safety Guideline for the Electrical
Design of Semiconductor Manufacturing Equipment
Revisions related to Short Circuit Current Ratings
Developing/Revising Body
SCCR Task Force
Name/Type:
Technical Committee: EHS, FPD
NA
Region:
Leadership
Position
Last
Leader
Karl
Author/Editor* Bryan
Editor*
Sklar
First
Edward
Matt
Eric
Affiliation
Applied Materials
Intel Corporation
SafetyGuru
Documents, Conflicts, and Consideration
Safety related codes, standards, and practices used in developing the safety guideline, and the
manner in which each item was considered by the technical committee
# and Title
Manner in Which the Standards was Considered in This
Safety Guideline
UL 508A, Industrial Control Panels
Reviewed the procedure for determining SCCR of Industrial
Control Panels, as specified in Supplement SB.
Cooper Bussmann, Bulletin EPR-1,
Reviewed the point-to-point method for determining SCCR
http://www.bussmann.com/library/docs/EPR_ from one end of a conductor to another, as well as SCCR of
Booklet.pdf
transformer output.
NFPA 79-2007, Electrical Standard for
Reviewed the criteria for SCCR.
Industrial Machinery 2007 Edition
NFPA 70, National Electrical Code
Reviewed the criteria for SCCR in Articles 670.3(A) and
Article 409.110.
SEMI S2, Environmental, Health, and Safety Reviewed the criteria for SCCR.
Guideline For Semiconductor Manufacturing
Equipment
SEMI S22, Safety Guideline for the Electrical Reviewed the criteria for SCCR.
Design of Semiconductor Manufacturing
Equipment
SEMI S26, Environmental, Health, and Safety Reviewed the criteria for SCCR.
Guideline for FPD Manufacturing Equipment
IEC 60204-1 Safety of Machinery – Electrical Reviewed the criteria for short-circuit rating.
Equipment of Machines, Part 1
IEC 60204-33 Safety of Machinery –
Reviewed the criteria for short-circuit rating.
Electrical Equipment of machines, Part 33:
Requirements for Semiconductor Fabrication
Equipment
iv
Known inconsistencies between the safety guideline and any other safety related codes,
standards, and practices cited in the safety guideline
# and Title
Inconsistency with This Safety Guideline
None
Other conflicts with known codes, standards, and practices or with commonly accepted safety
and health principles to the extent practical
# and Title
Known Conflicts with this Safety Guideline
None
Participants and Contributors
Last
Karl
Bryan
Crockett
Wong
Guild
Rehder
Petry
Roberge
Greenberg
Kapur
Palmero
Sigmund
Krov
Sklar
Kennis
Kryska
First
Edward
Matt
Alan
Carl
Ed
Alan
Bill
Steve
Cliff
Ken
Edwin
Peter
Alan
Eric
Debbie
Paul
Company
Applied Materials
Intel Corporation
KLA-Tencor
AKT America, Inc.
IBM Corporation
Underwriters Laboratories
IBM Corporation
Axcelis
Nikon Precisions
KLA-Tencor
Applied Materials
Applied Materials
Tokyo Electron of America
Safety Guru
Semitool
Novellus
Email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
The content requirements of this checklist are documented in Section 14.2 of the Regulations
Governing SEMI Standards Committees.
v
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
SEMI Draft Document #4773
Line Item Revisions to SEMI S22, Safety Guideline for the Electrical
Design of Semiconductor Manufacturing Equipment
Revisions related to Short Circuit Current Ratings
Line Item 1, Part A: Revise Note 12 in Section 5.1.66 of SEMI S22 to
include reference to Related Information 3 defining the available fault
current at a typical facility.
Text to be removed is shown struck through; text to be added is shown underlined. Only the text
that is struck through or underlined is proposed to be changed by this Line Item.
5.1.66 short circuit current rating — the maximum prospective available current to which an equipment supply
circuit is intended, by the equipment manufacturer, to be connected.
NOTE 12: Short circuit current rating for an electrical system is typically based on the analysis of short circuit
current ratings of the components within the system. See UL 508A and Related Information 2 for methods which
may be used to determine short circuit current rating. Related Information 3 describes the available fault current at given
piece of equipment in a typical semiconductor facility to be considered during semiconductor equipment and semiconductor
facility design.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 1
Doc. 4773  SEMI
LETTER BALLOT
Document Number: 4773
Date: 2010/04/16
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
Line Item 1, Part B: Add Related Information 3 to SEMI S22 with
Available Fault Currents for Different Nominal Voltages and Full Load
Current at a Typical Facility.
The following text is proposed to be added as Related Information 3 to SEMI S22. For ease of
reading, it has *not* been underlined.
RELATED INFORMATION 3 – Available Fault Currents for Different
Nominal Voltages and Full Load Currents at a Typical Facility.
NOTICE: This related information is not an official part of SEMI S22 and was derived from the work of the global
Environmental, Health & Safety Committee. This related information was approved for publication by full letter
ballot.
R3-1 Introduction
R3-1.1 While there are a number of product safety standards specifying short circuit current rating of the equipment
or its industrial control panel to be included on the equipment nameplate, they offer no guidance in terms of
reasonable target values towards which equipment designers should strive. As a result, end-users of the equipment
are often faced with the challenge of installing equipment which has a lower short circuit current rating than the
available fault current from the facilities. In an effort to address this challenge, the industry developed a set of
descriptions of available fault current values that are likely to exist in a “typical” end-use facility.
R3-1.2 Table-R3-1 describes the available fault currents at the facility points of connection terminals for equipment
in a typical semiconductor facility based on the equipment's nominal voltage and maximum full load amperes
ratings. This information is provided for consideration in designing semiconductor facilities and semiconductor
equipment. The installation challenges described above will be reduced if facility designers strive not to exceed
these values and equipment designers strive to meet or exceed these values.
R3-1.3 The following assumptions were used to establish the typical electrical distribution system in a
semiconductor manufacturing facility, based on IEEE and ANSI Standards (e.g., IEEE Standard 551 for Calculating
Short Circuit Currents in Industrial and Commercial Power Systems, IEEE Standard 141 for Electric Power
Distribution for Industrial Plants, IEEE Standard 399 for Power System Analysis, ANSI C37.010 for Application
Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis), as implemented by
commercially available software (e.g., EasyPower®). See Figure R3-1 for a graphical representation of this system
showing its components and available fault currents.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Infinite utility source at the primary of a 12.5kV to 480V transformer
2500kVA, 7% Z, 12.5kV-480V transformer
3.48 m (10 ft) of 4000A bus from the transformer secondary to the 480V switchgear
7.62 m (25 ft) of wire from the 480V switchgear to a 480V 1200A distribution board
7.62 m (25 ft) of wire from the 480V distribution board to the primary of a 480V-208V transformer
300kVA, 4%Z, 480V-208V transformer
7.62 m (25 ft) of wire from the transformer secondary to a 208V 1000A distribution board
3.48 m (10 ft) of wire from the 208V distribution board to a 208V 200A panel board
12.19 m (40 ft) of wire from the 480V distribution board to 480V equipment with FLA 16A thru 640A
12.19 m (40 ft) of wire from the 208V distribution board to 208V equipment with FLA 64A thru 320A
12.19 m (40 ft) of wire from the 208V panel board 208V equipment with FLA 16A thru 56A
All wires sized based on the 75 deg C ampacity rating for copper conductor
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 2
Doc. 4773  SEMI
LETTER BALLOT
Document Number: 4773
Date: 2010/04/16
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
LETTER BALLOT
Document Number: 4773
Date: 2010/04/16
Figure R3-1: Graphical Representation of Typical Facility and its 3 Phase Fault Current
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 3
Doc. 4773  SEMI
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
Table R1-1 Available Fault Current for equipment with nominal voltages and maximum rated
equipment full load current (FLA).
Available Fault Current [kA]
Nominal Voltage#1
120 V
Max Rated Equipment Full
Load Current (FLA)
Nominal Voltage#1
208 V
Nominal Voltage#1
480 V
16
1
2
4
24
2
2
6
32
3
4
9
40
3
4
9
48
4
5
13
56
5
7
19
64
7
19
72
8
21
80
8
21
88
9
24
100
10
26
120
11
28
140
11
29
160
12
30
180
12
31
200
12
32
240
13
32
280
13
33
320
14
35
360
14
36
400
14
36
480
14
36
560
14
37
640
14
37
#1
Voltages expressed represent nominal U.S. voltages. The closest corresponding nominal voltage(s) could be used for non-U.S. power systems.
NOTICE: SEMI makes no warranties or representations as to the suitability of the safety guideline(s) set forth
herein for any particular application. The determination of the suitability of the safety guideline(s) is solely the
responsibility of the user. Users are cautioned to refer to manufacturer’s instructions, product labels, product data
sheets, and other relevant literature respecting any materials or equipment mentioned herein. These safety
guidelines are subject to change without notice.
By publication of this safety guideline, Semiconductor Equipment and Materials International (SEMI) takes no
position respecting the validity of any patent rights or copyrights asserted in connection with any item mentioned in
this safety guideline. Users of this safety guideline are expressly advised that determination of any such patent
rights or copyrights, and the risk of infringement of such rights are entirely their own responsibility.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 4
Doc. 4773  SEMI
LETTER BALLOT
Document Number: 4773
Date: 2010/04/16