Upload
phungnga
View
247
Download
0
Embed Size (px)
Citation preview
1
ULUL’’s Future Approach to s Future Approach to Surge Protective DevicesSurge Protective Devices
byby
JoeJoe De De GregoriaGregoria, P.E., P.E.Primary Designated Engineer Primary Designated Engineer
Surge Protective DevicesSurge Protective DevicesUnderwriters Laboratories, IncUnderwriters Laboratories, Inc..
Thank you for giving me the opportunity to make this presentation today.
UL has been evaluating and Listing low voltage TVSS since the first edition of UL 1449 in 1985. Recently the 3rd edition of
UL 1449 was published and the transition from the 2nd to the 3rd edition will be the subject of this presentation.
2
Past PracticePast Practice
22ndnd edition of UL 1449, edition of UL 1449, Standard for Transient Voltage Standard for Transient Voltage
Surge Suppressors (TVSS)Surge Suppressors (TVSS)
As many of you know the 2nd edition has been used to
evaluated TVSSs since 1996 and included many safety
enhancements from the first edition, notably the Abnormal
Overvoltage testing added to simulate a loss neutral
situation and to establish short circuit current ratings for
permanently wired TVSSs.
3
2ND Edition
TVSS- Up to 600 V
Installation only on the load side of the service equipment overcurrent device -Article 285 of NFPA 70 (NEC)
One critical aspect of the 2nd edition was that it covered
TVSSs installed on the load side of the service equipment
OCP as limited in NEC article 285. The standard covered
cord connected, DPI and permanantly wired TVSSs rated
600V max.
4
Past PracticePast Practice
Surge ArrestersSurge Arresters-- up to 600v up to 600v line or load sideline or load side--Article 280 of Article 280 of
NFPA 70 (NEC)NFPA 70 (NEC)
IEEE C62.1, Standard for IEEE C62.1, Standard for Metal Oxide Surge Arresters Metal Oxide Surge Arresters
for AC Power Circuitsfor AC Power Circuits
The 2nd edition did not cover Surge Arresters as covered in
NEC article 280. These devices were evaluated to IEEE
C62.1 Standard for Metal Oxide Surge Arresters for AC
Power Circuits. Surge Arresters were considered a
different breed of surge protective devices permitted to be
connected to the line side, as well as the load side, of the
service equipment OCP. These SPDs were typically
installed on the service drop and intended to protect
against lightning surges.The surge testing, as specified in
the the IEEE standard, was more rigorous than the second
edition of UL 1449, but did not include the abnormal
overvoltage testing and short circuit current testing that
was part of the 2nd edition.
5
Past PracticePast PracticeLightning Protection SystemsLightning Protection Systems--UL UL
Master LabelMaster Label-- UL 96A (NFPA UL 96A (NFPA 780)780)
Required Surge Arresters or Required Surge Arresters or TVSS suitable for Lightning TVSS suitable for Lightning
Protection InstallationsProtection Installations
Because Surge Arresters were associated with lightning protection they were the only SPD permitted within UL Master Labeled Lightning Protection Installations. In 2004 UL announced a special TVSS for LPS that underwent additional testing and would be permitted within a UL96A installation.
Listed TVSS may be additionally marked “TVSS for LPS” if they:
1) Remain functional after the 10KA Surge Test as verified by the Measured Limiting Voltage
Test; and
2) Comply with the overvoltage test at 137.5% of the nominal system voltage.
RATIONALE
a) TVSS exhibit an acceptable “end of life” condition based on the Short Circuit Current and
Abnormal Overvoltage Tests of UL 1449.
b) They are limited to connection on the load side of the service disconnectovercurrent device.
c) TVSS would be additionally challenged via the 10KA Surge Test, followed by the Measured
Limiting Voltage Test, and the Overvoltage test.
6
Future Practice3rd Edition UL1449,Standard for Surge Protective Devices
(October 2, 2006)
Incorporates TVSS and Surge Arresters up to 1000V in one
UL Standard – RenamedSurge Protective Devices
Spearheaded by the 3rd Edition task group, made up of several people sitting in this room today, through many painstaking hours of discussions, meetings and teleconferences developed the first draft of the 3rd edition for comment by the STP. After several rounds of STP comments and resolution meetings the final draft of the 3rd edition was sent out for ballot and consensus to accept the standard was achieved.
The 3rd edition was finally adopted the end of September, 2006 and was published October 2, 2006.
The striking difference between the 2nd and 3rd edition is a new name- Surge Protective Devices that incorporates TVSSs and Surge Arresters in one standard..
7
In the 3rd Edition UL 1449
SPDs are designated as
Type 1, 2, 3 or 4
It incorporates the different SPDs (Surge Arresters, TVSS) in a single standard with Type designations established as 1, 2, 3 and 4 and based on installation location within the electrical distribution system.
8
Type 1 SPDsType 1 SPDsPermanently connected Permanently connected Installed between the Installed between the
secondary of thesecondary of theservice transformer and the service transformer and the
line or load side of the service line or load side of the service OCPOCP
WWithoutithout external OCPexternal OCP
Type 1 – Permanently connected SPDs intended for installation between the secondary of the service transformer and the line or load side of the service disconnect equipment overcurrent device, including watt-hour meter socket enclosures and intended to be installed
without an external overcurrent protective device.
IEEE C62.34 Type SPDs
9
Type 2 SPDsPermanently connected
Intended for installation on the load side of the
service equipment OCP
Includes SPDs located at the branch panel.
Type 2 – Permanently connected SPDs intended for installation on the load side of the service disconnect equipment overcurrent device; including SPDs located at the branch panel.
IEEE C62.62 Type SPDs.
10
Type 3 SPDsPoint of utilization SPDs
Installed 10 meters (IEEE C62.41) from the electrical
service panel
Includes cord connected,direct plug-in, receptacle type
and SPDs installed at the equipment being protected.
Type 3 – Point of utilization SPDs, installed at a minimum conductor length of 10 meters (30feet) from the electrical service panel to the point of utilization, for example cord connected,
direct plug-in, receptacle type and SPDs installed at the utilization equipment being protected.
See marking in 65.2. The distance (10 meters) is exclusive of conductors provided with or used to attach SPDs.
The 10 meters (30 feet) comes from IEEEC62.41 where location A, outlets and long branch circuits, shall be more than 10 meters from category B, Service Entrance. 3rd
edition testing for Type1 and 2 SPDs (location B) is different from the testing for Type 3 SPDs (location A).
11
Type 4 SPDs
Component SPDs, including discrete components as well as
component assemblies.
Type 4 SPD can be a single discrete MOV or a module/assembly consisting of different SPD components, including multiple MOVs, GDT, air gap, SAD, etc. intended to be installed with an overall complete SPD.
12
33rdrd Edition TestingEdition Testing
All SPD TypesAll SPD Types6KV/3KA Combination wave for 6KV/3KA Combination wave for
Voltage Protection Voltage Protection Rating(previously SVR)Rating(previously SVR)
2nd edition MLV testing to establish what was called the SVR was 6KV/500A combination wave.
3rd Edition testing for all SPD Types is at 6KV/3KA combination waveform representing the high level of surge exposure (IEEE C62.41.)
13
33rdrd Edition TestingEdition TestingType 1 and 2 SPDsType 1 and 2 SPDs
Nominal Discharge Current,In,Nominal Discharge Current,In,15 surges, 8x20us current 15 surges, 8x20us current
wave impressed through the wave impressed through the SPD SPD
Similar To IEC 61643Similar To IEC 61643
After the MLV testing the same samples of Type 1 and 2 SPDs, will be subjected to an 8x20 us surge current impressed through the SPD, similar to the In testing in IEC 61643.
38.7.1 The manufacturer shall specify (declare) the value of the Nominal Discharge Current (In) to which the sample will be tested. The value of the Nominal Discharge Current (In) selected by the manufacturer shall be: 10 kA or 20 kA for Type 1 SPDs and 3 kA, 5 kA, 10 kA or 20 kA for Type 2 SPDs. The surge generator shall be adjusted to ensure that the value of In (selected by the manufacturer) is impressed through the SPD.
38.1. The same three representative devices that were subjected to the 6 kV/3 kA combination wave in the Voltage Protection Rating Test, shall then be subjected to fifteen (15) x 8/20 short circuit current surges, per mode. The surges are to be applied at the application points specified in 38.4.
38.7.3 During the application of these surges the samples are unenergized. Surges shall be applied in three groups of five surges. Within 1 second after the application of each surge, the manufacturer’s
specified (declared) MCOV shall be applied for 60 seconds ±15 seconds. After each group of 5 surges, the sample shall rest for 30 minutes ±5 minutes. After the 15th surge, the MCOV shall be re-applied for at least 15 minutes.
.
14
Type 1 SPDType 1 SPDNominal Discharge CurrentNominal Discharge Current
10KA or 20 KA10KA or 20 KAto comply with lightning to comply with lightning
protection (UL96A, NFPA780)protection (UL96A, NFPA780)
Type 2 SPDType 2 SPDIn = 3KA, 5KA, 10KA or 20 KAIn = 3KA, 5KA, 10KA or 20 KA
Type 1 SPDs can be rated and tested for 10 or 20 KA corresponding to the requirements in NFPA 780, Standard for the Installation of Lightning Protection Systems and eventually UL 96A (Master Labeled LPS).
Type 2 SPDs can be rated and tested at 3, 5, 10 or 20 KA
15
Type 3 SPDType 3 SPD
Operating Duty Cycle Operating Duty Cycle 15 Surges, Combination 15 Surges, Combination
wave, at 6KV/3KA, wave, at 6KV/3KA,
After the MLV for the VPR the same samples of Type 3 SPDs are subjected to 15 surges of 6KV/3KA combination waveform similar to Class III SPDS in IEC 61643.
38.8 Operating Duty Cycle Test – For Type 3 SPDs
38.8.1 Type 3 SPDs or Type 4 SPDs (intended for locations in which a Type 3 SPD may be installed),
shall be energized and subjected to the Operating Duty Cycle Test while connected to a rated power
source. The same three representative devices that were subjected to the 6 kV/3 kA Combination Wave
Surge, shall be subjected to fifteen (15) x 6 kV/3 kA combination wave surges, per mode, as specified in
Table 38.1, applied at the application points specified in 38.4. Eight (8) surges shall be positive polarity at
a phase angle of 90 (+0, -15) degrees and 7 shall be negative polarity at a phase angle of 90 (+0, -15)
degrees. The surges are to be conducted in succession with a maximum 60 second period between each
surge.
16
Type 4 SPDType 4 SPD
Testing based on application Testing based on application as Type 1, 2 or 3 SPDas Type 1, 2 or 3 SPD
Type 4 SPDs are tested based on their intended application as Type 1, 2, or 3 SPDs.
Type 4 SPDs intended for other than SPD applications (appliances, etc.) may be tested at
the manufacturer’s stated rating.
17
Voltage Protection Voltage Protection RatingRating
Repeated after In or Repeated after In or Operating Duty Cycle Operating Duty Cycle
Shall not deviate by more Shall not deviate by more than 10% from initial VPRthan 10% from initial VPR
The same 3 samples that were subjected to In testing or Operating Duty Cycle testing are again subjected to the VPR test. 3 surges at 6KV/3KA, combination waveform.
VPR shall not deviate by more than 10% from the initial VPR.
18
Operational VoltageOperational Voltage
115% of rated SPD voltage115% of rated SPD voltage
Following the repeated VPR tests the same samples shall be subjected to an overvolate at 115% of rated voltage.
Following the repeated VPL VPR Test (6 kV/3 kA Combination Wave Surge), the SPD shall be subjected to an overvoltage of 115 percent of the rated supply voltage (to simulate the upper tolerance of the supply voltage) for 30 minutes. The SPD must remain operational and shall meet the pass criteria as specified in 39.5. For SPDs intended for use on ungrounded systems, impedance grounded systems, or corner grounded delta systems, the line-to-ground modes shall be tested at 115% of the rated line-to-line voltage.
39.5 Pass Criteria – During and following the overvoltage tests the following conditions shall not result:
a) Emission of flame, molten metal, glowing or flaming particles through any openings (preexisting
or created as a result of the test) in the product.
b) Charring, glowing, or flaming of the supporting surface, tissue paper, or cheesecloth.
c) Ignition of the enclosure.
d) Creation of any openings in the enclosure that results in accessibility of live parts, when
e) Supplementary protective devices, internal or external to the SPD, opening.
19
Current TestingCurrent Testing
Type 1 and 2 SPDType 1 and 2 SPDShort Circuit Testing (forced Short Circuit Testing (forced
conduction of SPD) and Short conduction of SPD) and Short Circuit Current Rating (NEC Circuit Current Rating (NEC
requirement)requirement)
Type 1 and 2 SPDs are subjected to this test at the SCCR of the SPD chosen by the manufacturer(5KA- 200KA).
Type 1 SPDs are tested with no series OCP unless provided as part of the overall equipment.
Type 2 can be tested in series with a specific type of OCP, circuit breaker or fuse that will be marked on the SPD.
SPDs are subjected to twice the rated voltsge to force conduction or the following options are applied:Exception: For permanently connected (Type 1 and Type 2SPDs) devices that do not conduct current (beyond leakage current) when subjected to the test, any one of the following options, or any combination thereof, shall be implemented and the test described in 40.2.1 repeated:a) Short out any voltage switching components with solid wire that shall not open during this
test;
b) Increase the test voltage above the values in 40.1 until operation occurs; or
c) Use lower voltage rated (MCOV shall be in a range of 60 – 80 percent of the nominal
system voltage) nonlinear voltage limiting components from the same manufacturer and product family with identical chemical composition. Test the lower voltage rated component at the
maximum voltage specified in 40.1.
d) For voltage switching-type SPDs, a combination waveform surge shall be applied on the ACpower source at a voltage level to turn on the SPD.
Pass criteria – During and following the tests described in 40.2.1 – 40.4.2, the following
conditions shall not result:
a) Emission of flame, molten metal, glowing or flaming particles through any openings (preexisting
or created as a result of the test) in the product.
20
Intermediate Current Level Intermediate Current Level TestingTesting
Type 1 and Type 2 SPDType 1 and Type 2 SPD1KA, 500A, 100A1KA, 500A, 100A
Type 3 SPDType 3 SPD50A, 150A and 1kA or 2KA50A, 150A and 1kA or 2KA
Type 1 and 2 SPD are subjected to twice rated voltage to force conduction or the following options are applied:
For permanently connected devices that do not conduct current (beyond leakage current) nor
exhibit any conditions described in 40.1.11 when subjected to the test, any one of the following options,
or any combination thereof, shall be implemented and the test described in 40.3.1repeated:
a) Short out any voltage switching components with solid wire that shall not open during this
test;
b) Increase the test voltage above the values in 40.1 until operation occurs; or
c) Use lower voltage rated (MCOV shall be in a range of 60 - 80 percent of the nominal system voltage) nonlinear voltage limiting components from the same manufacturer and product family with identical chemical composition. Test the lower voltage rated component at the maximum
voltage specified in 40.1.
d) For voltage switching-type SPDs, a combination waveform surge shall be applied on the AC power source at a voltage level to turn on the SPD.Type 3 are connected to twice rated voltage for 7 hours.
21
Limited CurrentLimited Current
Type 1 or 2 SPDType 1 or 2 SPD10A, 5A, 2.5A, .5A10A, 5A, 2.5A, .5A
Type 3 SPDType 3 SPD5A, 2.5A, .5A, .125A5A, 2.5A, .5A, .125A
Four previously untested representative devices of the SPD for each combination of conductor pairs that were tested in accordance with Section 38, are to be connected to an ac power supply having
an open circuit voltage equal to the test voltage specified in Table 40.1. The power supply is to incorporate a series variable resistor that can be adjusted to obtain the short-circuit current (Isc) specified below. See
adjusted such that Isc equals the values specified in Table 40.6. The four representative devices are to be energized for 7 hours,or until current to, or temperatures within the SPD attain equilibrium, or until the
SPD becomes disconnected from the ac supply (due, for example, to open circuiting of a thermal or overcurrent protective device).
Type 4 SPDs shall be tested based on the intended application.
22
SPD MarkingSPD Marking
SPD TypeSPD TypeElectrical RatingsElectrical Ratings
VPRVPRIn,MCOV for Types 1 and 2In,MCOV for Types 1 and 2
SCCR for Types 1 and 2SCCR for Types 1 and 2
An SPD shall be plainly and permanently marked with the following information:
a) The name of the manufacturer or other descriptive marking by which the organization
responsible for the product can be identified;
b) A distinctive catalog number or equivalent designation;
c) SPD Type (1,2,3). Type 4 (assembly or module) SPDs shall be marked based on the
performed testing for Type 1, 2 or 3 applications;
d) Electrical ratings per Section 64;
e) Nominal Discharge Current (In) Rating (64.1);
f) Maximum Continuous Operating Voltage Rating (MCOV) (64.1);
g) Voltage Protection Rating (VPR) (64.2)
h) Date or period of manufacture not exceeding any three consecutive months which is able to
be abbreviated or in a nationally accepted code;
i) Short Circuit Current Rating (SCCR) (65.11 and 65.11);
23
2008 NEC2008 NEC
Article 285 will reflect 3Article 285 will reflect 3rdrd
Edition UL 1449 Type Edition UL 1449 Type designationsdesignations
Article 280 will cover Surge Article 280 will cover Surge Arresters over 1KV evaluated Arresters over 1KV evaluated
to IEEE C62.11to IEEE C62.11
Proposals for 2008 NEC
Article 285 will replace the term TVSS with SPD up to 1KV and include SPD Types.
Article 100 (definitions) will include definitions of SPD Types 1, 2, 3 and 4.
Article 280 will cover Surge Arresters over 1KV evaluated by UL using IEEE C62.11-1999.
24
2007 NFPA 7802007 NFPA 780
Will reflect 3Will reflect 3rdrd edition UL 1449 edition UL 1449 In ratings for Type1 and 2 In ratings for Type1 and 2
SPDSPD
2007 NFPA780 will specify In requirements for SPDs in lightning protection installations that correspond to the In levels in the 3rd edition of UL 1449.
25
Where do we go from here?Where do we go from here?
File Review for all Certified File Review for all Certified TVSS and Surge Arresters for TVSS and Surge Arresters for compliance with the 3compliance with the 3rdrd Edition Edition
of UL 1449of UL 1449
36 month effective date.
26
Next Revision CycleNext Revision Cycle
Include the Verification of Include the Verification of Discrete Component Discrete Component
Parameters in the 3Parameters in the 3rdrd Edition Edition of UL 1449 to Facilitate the of UL 1449 to Facilitate the Interchangeability of Interchangeability of MOVsMOVs