Author Archive

Electric Meter Testing Requirements Updated in ANSI C12.1-2014

by admin on Oct.27, 2014, under Meters

Three weeks ago, MET Labs joined other C12 Accredited Standards Committee members in St. Louis, MO at the EEI Transmission, Distribution & Metering Conference to discuss revisions to ANSI C12.1, which provides the basic requirements for all kilowatthour metering devices, both electronic and electromechanical. 

This post highlights changes from the ANSI C12.1-2008 revision to the soon to be released ANSI C12.1-2014, as presented at the meeting by Jim Reed, MET’s Meter Accuracy Lab Manager.  ANSI C12.1 was modified in several sections to keep pace with industry trends and to provide clarity for tests.

Section 2
A number of definitions were added.

Section 3 (Performance requirements) – Tightened the % errors for portable and reference standards at reference conditions including a specific voltage and current. (Variation for reference condition) – Gave additional percent errors for Portable and Reference Maximum Percent Errors @ 23°C over the designed range of voltage and current.

Section 4
4.7.1 (Test conditions under performance requirements) – Adds some clarity for the calibration level of the meters prior to entering into testing.
4.7.2 (Accuracy tests – internal influences) – A host of changes in this section, including the addition of a 0.5% accuracy classification.   Contact MET for all of the changes in this section. (Insulation) – A few changes, including the addition of a requirement to disconnect components providing a path in parallel with the insulation to be tested. (Effect of high voltage line surges) – Adds an allowance for performing the accuracy performance check once after the completion of both a ring wave test and combination wave test. (Effect of operating temperature) – A few changes, including ramp timing change from 6 to 5 hours. (Effect of relative humidity) – A couple changes, including specifying test current between light load and class amps (same as

Section 5
A number of changes in this section, including:

  • Restructuring to provide clarity, guidelines and generally better reflect updated practices within the industry for in-service and new meter deployment.
  • A test plan must be in place for metering devices at various set intervals (periodic interval plan, variable interval plan or a statistical sampling plan).
  • Provides details for corrective actions that must be taken for any metering device or group of metering devices failing to meet performance criteria.
  • Added recommendations on test data that should be recorded for the annual performance test programs.
  • An Acceptable Quality Limit or AQL of 1.0% or less will be used to develop the acceptance criteria for all metering devices.
  • Service switches to fall under a statistical sampling plan.
  • Performance tests for integrated communication devices.

Appendix D (Periodic testing schedule) – Recommended periodic test program cleaned up to reference AMI meters specifically, and then all other meters.
Appendix F (Variable interval plan) – Includes an example of appropriate test rates based on failed meters.

Questions about the changes?  Ask Pat, our meter approvals expert.

Contact us to discuss your electricity meter testing requirements.

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AHJs Use NFPA 790 & 791 to Qualify Labs for Electrical Equipment Field Evaluations

by admin on Oct.14, 2014, under Product Safety

Authorities Having Jurisdiction (AHJs) in the United States have typically used the National Electrical Code, NFPA 70, as the basis for approving electrical equipment installations in the United Sates. Much of the Code relies on having products manufactured and certified by a recognized testing laboratory to consensus-based U.S. product safety standards.

In Canada, the AHJs use the locally adopted Code and rely on products certified to that country’s adopted product safety standards.

However, this approach has historically proved challenging for AHJs, so industry organizations have created additional guidance documents.  Here is a short history of this effort:

2003 – The American Council for Electrical Safety (ACES) publishes the Recommended Practice and Procedures for Unlabeled Electrical Equipment Evaluation.  It became the de facto guide for delivering field evaluations.
2005 – ACES approves the Recommended Competency Guidelines for Third-Party Field Evaluation Bodies.  It uses ISO Guide 65 as its foundation with input from ISO/IEC 17020.
2006 – The International Accreditation Service (IAS), a subsidiary of the International Code Council (ICC), issues AC 354, Accreditation Criteria for Field Evaluation of Unlisted Electrical Equipment.
2008 – The National Fire Protection Association (NFPA) forms the Technical Committee for Electrical Equipment Evaluation (EEE).
2011 – The 2012 editions of NFPA 790, Standard for Competency of Third-Party Field Evaluation Bodies and NFPA 791, Recommended Practice and Procedures for Unlabeled Electrical Equipment Evaluation — are adopted.
2013 – IAS adopts an updated AC 354 that references NFPA 790 & 791.
2013 – The 2014 editions of ANSI/NFPA 790 and ANSI/NFPA 791 are issued.

NFPA 790 and NFPA 791 provide AHJs with the ability to qualify who can complete field evaluations for electrical products.  Read more about what is specified in these standards in a previous Compliance Today blog post.  

MET Labs is one of just a few agencies that operates a NFPA 790 & 791 Quality Management System in addition to being NRTL- and SCC-accredited.  Contact us for a free field evaluation quotation.

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ENERGY STAR Certification for Computers Now to Version 6.1

by admin on Oct.06, 2014, under ENERGY STAR

Now Eligible for ENERGY STAR Certification

As of September 10th, 2014, the U.S. Environmental Protection Agency’s (EPA) ENERGY STAR Version 6.1 requirements took effect. This newer version expands the scope of the computers program to include two new product types and a subtype of Notebook Computers. EPA chose to add Slates/Tablets, and Portable All-In-One computers to their product list and a Two-In-One Notebook subtype. Power management and energy efficiency criteria have also been added to the two new product types.

Note to manufacturers:  These changes to the ENERGY STAR scope do not have an effect on previously certified products.

MET Labs is an EPA-recognized lab and/or certification body for 15 ENERGY STAR product categories.  Get a free quote now to evaluate your product to Version 6.1 or any other energy efficiency standard.

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MIL-STD-461 for Military EMC & GR-1089-CORE for NEBS Telecom EMC Share Some Requirements

by admin on Sep.30, 2014, under EMC, Military, NEBS

The electromagnetic compatibility (EMC) requirements for telecom and military equipment are considered among the most difficult to meet for any industry.  Not many electronics manufacturers conduct testing for both requirements, but it happens occasionally.  For those who do, it’s an advantage to pursue both at the same time, as there is some overlap.  Following is a short MET Labs overview on some of the primary similarities and differences.

One of MET's ESD Testing Rooms

MIL-STD-461 is the primary EMC standard for military approvals.  The current version is MIL-STD-461F, but previous versions may still be specified in U.S. military contracts. 

GR-1089-CORE is the primary EMC standard for telecommunications (NEBS) equipment.  The current version is Issue 6.

MIL-STD-461  is similar to section 2 and 3 of GR-1089 in that they both include EMC conducted and radiated emissions and susceptibility requirements, however the test methods are quite different.

For emissions, MIL-STD-461 requires use of a peak detector and the limits are more stringent for some platforms, like Army Ground.  On the other hand, the radiated emissions test method could be considered less thorough because the test antenna and EUT are placed in one position, while for GR-1089 radiated emissions, the EUT is rotated 360 degrees and the antenna height is adjusted to find the maximum radiated emissions.

For susceptibility testing, MIL-STD-461 test method CS114 is similar to GR-1089 conducted susceptibility.  Test method CS115 is somewhat similar to GR-1089 section 2 EFT.  RS103 is similar to GR-1089 radiated susceptibility, however, for some military platforms, the test level is much higher than GR-1089 (up to 200V/m).

MIL-STD-461 does not include ESD testing, although many military test programs include IEC 61000-4-2 ESD testing along with -461.  GR-1089 includes ESD testing in section 2 and references IEC 61000-4-2 for the test procedure.

Another occasionally-referenced military standard – MIL-STD-1399-070 DC Mag Field – is not like any GR-1089 test.  This is a 1600A/m DC field, which is quite strong.  If the EUT has no magnetic sensors, compass, or other magnetically sensitive components, it shouldn’t be a problem.  If the EUT does have those components, it would have to be specifically designed to withstand this test.

Read more about testing to MIL-STD-461 or GR-1089-CORE, or request a free quotation for an upcoming test need.

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For Product Safety Approvals, Uncertified and Improperly-Rated Components Require Surveillance

by admin on Sep.24, 2014, under Product Safety

Electrical/electronic equipment manufacturers often ask if it is acceptable to use uncertified or improperly rated components in their products.  The following Frequently Asked Questions address the implications of using these components for North America product safety approvals

An uncertified power suppply?

What is an uncertified component?

Any safety critical component that is not certified by a suitably accredited agency and that does not provide surveillance comparable to that required by United States and Canadian regulatory schemes.

What is an example of an uncertified component?
Some examples include power supplies, transformers, plastics, insulation, adhesives, potting compounds and more.

Is an improperly rated component the same as an uncertified component?
No.  An improperly rated component is any safety critical component that, though it may be certified by a suitably accredited agency that does provide surveillance comparable to that required by United States and Canadian regulatory schemes, is not rated for the end-product application.

What is an example of an improperly rated component?
Some examples include power supplies connected to supply voltages greater than for which they are certified or flammable plastics rated for HB but required to be V-2 or better.

You used the term safety critical component – what does that mean?
Safety critical components are any component, material or substance that, if its performance or features change, can affect compliance with the essential safety requirements of the applicable standards.

Ok, I have equipment with uncertified/improperly rated components in it, what do I do now?
Usually the easiest route is to replace the component in question with one properly rated and certified for the end product application.  Second easiest is to have the component certified by its manufacturer, if that’s possible.  The final option is to have the component evaluated and tested by MET Labs, with a schedule for continued compliance.

I understand it may take more time and money to safety certify a product with uncertified/improperly rated components in it, but are there other implications also?
Yes.  If using uncertified components, there is no assurance of continued compliance even after evaluation and testing in product.  If certified but improperly rated, there is no assurance of continued compliance even if tested in product.  Changes may be made by the manufacturer that allow the item to remain compliant with original certification but that might cause it to become non-compliant in the end product application.

Is continued compliance a regulatory requirement?
Yes.  The United States and Canadian certification schemes require surveillance to assure continued compliance.  Surveillance applies to the end product and its components.

How is continued compliance enforced for a MET-certified component?
If a repeat of testing is not necessary and the item is not too complex to inspect at the same time as the end product inspection, the item may be described in detail in our report and our follow up inspector will verify continued compliance during the end product factory inspection.  It is necessary that the report contain sufficient product description and instructions for effective surveillance.

More complex components are returned to the laboratory on a minimum of an annual basis for reevaluation and perhaps some retesting.  Some components or circumstance might require more frequent surveillance. 

Contact us for a question about component integration into your equipment, or for a free quote for an upcoming product evaluation.

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MIL-STD-461 EMC Testing FAQs for Military and Marketing Requirements

by admin on Sep.08, 2014, under EMC, Military

MIL-STD-461 is the standard that defines the test limits, test levels, and test procedure for various electromagnetic phenomena for electronic equipment used by the U.S. Army, Navy, and Air Force on all platforms (ground, sea, and air).  MIL-STD-461F is the latest version.  Following are answers to common questions about this often-utilized military EMC standard.

Where can I find MIL-STD-461 and how much does it cost?
The standard is free and approved for public release.  It can be downloaded from a number of sites, but we recommend using the official U.S. Defense Logistics Agency (DLA) ASSIST site.  This site requires registration and a wait for approval.

What is included in MIL-STD-461?
Test methods cover electromagnetic emissions, which are an unintended, but unavoidable byproduct of every electronic device, as well as electromagnetic susceptibility, which is a measure of the equipment under test’s (EUT) ability to withstand electromagnetic disturbances.

Test methods include specific types of conducted, radiated, transient, and continuous emissions and susceptibility tests.  See a full list of test methods on MET’s Military EMC Testing page.

The first few sections define general aspects of the standard and testing, such as terminology, test facilities, test equipment, setup of the EUT, applicable tests for equipment to be used on various platforms, etc.

Section 5 contains a test procedure for each test method, which defines the test equipment needed, instructions for setup, and a procedure for how to conduct the test.

Is compliance with MIL-STD-461 mandatory?
MIL-STD-461 is usually only required when part of a specific military contract between the U.S. military and an electronic equipment manufacturer.

The contract would specify the specific test methods within -461 which need to be performed and passed by the equipment being built for the military.

MIL-STD-461 testing is sometimes voluntarily performed by electronic equipment manufacturers for marketing purposes, to attract possible military contracts and/or for quality purposes, to ensure a rugged design.

I want to voluntarily perform MIL-STD-461 testing and am not worried about my EUT’s susceptibility to electromagnetic disturbances.  What are the best test methods for determining compliance with the standard’s electromagnetic emissions requirements?
CE102 and RE102 are the most applicable test methods for this.

CE102, conducted emissions, power leads, 10 kHz to 10 MHz, is performed to verify that electromagnetic emissions from the EUT do not exceed the specified requirements for power input leads, including returns.

This will ensure that the EUT does not cause interference to other electronic equipment operating from the same power source, since the emissions can conduct along the supply lines.

A special piece of test equipment called a line impedance stabilization network (LISN) is connected in series with each conductor of the input power lines to the EUT.

The LISN establishes a 50 Ohm impedance on the power line and has a coaxial measurement port, which allows for connection to a 50 Ohm spectrum analyzer for measurement of the RF emissions.

The EUT is exercised in a way typical of its normal use and the emissions are compared to the limit.  If CE102 emissions exceed the limits, the tests are considered not compliant.

RE102, radiated emissions, electric field, 10 kHz to 18 GHz, is performed to verify that electric field emissions from the EUT and its associated cabling do not exceed specified requirements.

This will ensure that radiated emissions from the EUT do not cause interference to other electronic equipment operating nearby.

The EUT and test antenna are set up within a shielded test enclosure, which is internally lined with RF absorbent material.

The shielded enclosure prevents RF ambient noise from entering the test area, while the RF absorbent material reduces RF reflections from the metallic chamber walls, allowing for accurate radiated RF measurements of the EUT emissions with a test antenna.

The test antenna is connected through coaxial cable and chamber wall bulkhead connectors to the spectrum analyzer outside the test chamber.

The EUT is exercised in a way typical of its normal use and the emissions are compared to the limit.  If RE102 emissions exceed the limits, the tests are considered not compliant.

For MIL-STD-461 testing for marketing purposes only, does MET issue a test report?
MET can issue a test report and a one-page certificate upon completion of testing.

The test report and certificate would not guarantee acceptance of the product by the U.S. military.  However, you are free to use your engineering judgment to make claims of compliance for similar projects, based on the test report and certificate provided.

MET Labs has a reputation for high quality test results and our test reports will increase the credibility of your marketing claims.

Request a free quotation for MIL-STD testing for military or marketing requirements.

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IEC 60601-1 3rd Edition for Medical Electrical Equipment Continues to Gain Adoption in Global Markets

by admin on Sep.02, 2014, under Medical, Product Safety

The 3rd edition of IEC 60601, issued in 2005, is in various states of adoption by regulatory bodies around the world.  IEC 60601-1 is the harmonized standard for medical electrical equipment recognized by public health authorities in most countries.  Unlike 2nd edition, the 3rd edition requires a risk management file and process conforming to ISO 14971, the international standard for Application of Risk Management to Medical Devices, in order to show product conformance.

In addition to safety requirements, IEC 60601 includes particular standard requirements for functional safety, software, lasers and EMC.

Following are the known global transition dates. 

European Union (EU)
General Standard – June 1, 2012
Particular Standards – Varies, noted by the Official Journal (OJ) of the EU
General Standard with Amendment 1 (EN 60601-1:2006/A1:2013) – June 1, 2018

United States
FDA – From January 1, 2014, FDA requires the 3rd edition of the standard for new product submissions, while for existing products the 2nd edition is still acceptable.
NRTL – In March 2014, OSHA announced through a Federal Register Final Notice its incorporation of  ANSI/AAMI ES60601-1 into the list of Appropriate NRTL Program Test Standards.  This is the U.S. National Version of IEC 60601-1 + A1.

General Standard – June 1, 2012
Particular Standard – Varies, with a 3-year transition from the date of publication of the particular standard.

Published June 1, 2012, with potential transition in 2017

South Korea
Classes 3 and 4 + 14 Particular Products – June 1, 2014
Class 2 + 21 Particular Products – June 1, 2015
Class 1 + 19 Particular Products – June 1, 2016

Taiwan & Singapore
Recognize third edition, no transition date announced

MET Labs will continue to provide testing to the 2nd edition of IEC 60601 as long as regulatory bodies continue to recognize it. For those companies launching global products, it may be necessary to maintain a certified 2nd edition test report with local country deviations and also a 3rd edition test report. In those cases, MET offers a dual certification package at a bundled discount.

As a leading medical National Certification Body (NCB), MET can issue a CB Test Report and CB Certificate, for application to CB Scheme participating countries for local marketing approvals.

Contact us for an immediate test or certification need or sign up for an upcoming free webinar on 60601-1 3rd Edition Overview or 60601-1-2 4th Edition Medical EMC.

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EMI/EMC Testing Best Practices – Before & During Your Lab Visit

by admin on Aug.26, 2014, under EMC

Most electrical/electronic designs today are subject to electromagnetic interference/electromagnetic compatibility (EMI/EMC) testing.

Preparation before entering the test laboratory is vital.

Before Testing
The first step is to write a test plan. If you are working in the defense industry, a military test plan is usually a contract requirement. If not, you’ll still want one.  If you don’t know enough to create one, ask your lab to do it, or to recommend an independent consultant who can help.

A good test plan includes:

  • A configuration, mode of operation, and monitoring method, which represents a worst case scenario from an EMC perspective
  • Special software, test fixtures, and supporting equipment may be needed to exercise the equipment under test
  • A description of hardware to be tested, including peripherals & I/O configurations
  • An indication of which external power and data I/O ports need to be tested for each test method
  • Required tests
  • A definition of failure criteria
  • How to monitor, recognize & report failures
  • Special needs: Software, power, cooling, etc.

Then, get pricing and scheduling from a leading 3rd party test lab, like MET Labs.

You’ll have to determine what the lab will supply versus what you will supply.  You will need:

  • Equipment under test (EUT) & spares
  • Cables & connectors
  • Test fixture (for some programs)
  • Tool kit
  • EMI suppression supplies – ferrites, copper tape, etc.
  • The equipment’s design or compliance engineer or someone else familiar with the product to witness testing

In the Lab
Preliminary testing (pre-testing) is always a good idea.  Shortened versions of each test method can be performed to identify failures.  Design modifications can be made before final testing is scheduled.  A radiated emissions pre-test, often referred to as a pre-scan, is the most common pre-test performed.  Even if there is no plan to perform pre-testing for the other test methods, a radiated emissions pre-scan can identify failures and allow for design modifications, which will likely cause the equipment under test to perform better for the other test methods as well.

Then run the full program as specified in the test plan.  If you pass the first time, congratulations!  If not, don’t take it personally – it’s not unusual, especially with early-stage pre-compliance testing.  And practically anything can be overcome. 

If you fail a test, do some quick troubleshooting – you may be able to fix the problem right away.  Do the easy things first:

  • Verify that the EUT is still working properly. This is particularly important with immunity tests that might cause damage.
  • Unplug external cables to see if it improves results.  External cables, although not designed to do so, act as antennas to radiate emissions and receive RF interference.
  • Add ferrites to cables
  • Clean mating, conductive surfaces of paint and other materials.
  • Add an RF filter module at the power input to the equipment under test to limit RF emissions and protect from continuous conducted disturbances.
  • Add a MOVs or other transient limiting device at the power input to protect from transient disturbances.
  • To limit leakage, wrap the EUT in aluminum foil

For immunity, back off the test levels to determine the actual failure levels. If you are close, maybe a ferrite will fix things. If not, that’s good information to have – it will help you narrow the possible failure mechanisms.

Don’t be afraid to ask for suggestions.  Test engineers at an experienced lab like MET will have seen hundreds if not thousands of products, and know many debug and quick-fix solutions.

MET Labs is a full-service EMC testing lab with multiple convenient locations.  Contact us for a free quick-response quotation.

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OSHA Close to Authorizing NRTL Certification to ANSI/AAMI ES60601-1 for Medical Equipment

by admin on Aug.19, 2014, under Medical, Product Safety

After a long wait, medical electrical equipment manufacturers are looking forward to the Occupational Safety & Health Administration’s (OSHA) expected near-term recognition of one or more labs – including MET Labs – for product safety certifying medical devices to ANSI/AAMI ES60601-1:2005/(R)2012 under the U.S. Nationally Recognized Testing Laboratory (NRTL) Program.

In March 2014, OSHA announced through a Federal Register Final Notice its incorporation of  ANSI/AAMI ES60601-1 into the list of Appropriate NRTL Program Test Standards.  This version of the standard is the U.S. National Version of IEC 60601-1 + A1.

OSHA delayed NRTL recognition for the U.S. version of IEC 60601-1:2005 (3rd edition) due to what it saw as subjective compliance requirements, as well as statements in the standard that would have required the NRTL to accept statements from the manufacturer without the ability for the NRTL to verify the validity of these statements.

The changes in language introduced in Amendment 1 (496 changes for the IEC standard) allows the NRTL to verify the validity of data accepted from the manufacturer.

Here are some of the key changes in AAMI ES60601-1 as compared to UL 60601-1:

  • Clause 9.6 Acoustic Energy – Not included in UL 60601-1
  • Clause 9.7.2-.4 Pressure vessels and parts subject to pneumatic and hydraulic pressure – Not included in UL 60601-1
  • Clause 9.7.6 Pressure control device – Not included in UL 60601-1
  • Clause 9.8 Mechanical hazards associated with support systems – This is a unique mechanical test not included in UL 60601-1
  • Clause 11.2.1 Oxygen Rich Environment – An optional additional test if evaluation is not sufficient for proving that the product is not an ignition hazard in an oxygen-rich environment
  • Clause 15.3.5 Rough handling test – Additional ascending shock testing and door frame shock testing is included that was not present in UL 60601-1
  • Clause Lithium batteries – Not included in UL 60601-1

MET Labs is OSHA-recognized for UL 60601-1, and is expecting to soon be recognized for ANSI/AAMI ES60601-1:2005/(R)2012 as well.  Contact us for a free fast-response quote for electro-medical equipment testing and certification for any major market.

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FCC Part 15 DFS Testing Requirements Change for U-NII Devices

by admin on Aug.11, 2014, under EMC, Wireless

To accommodate changes in the Federal Communication Commission’s (FCC) Docket 13-49, the Dynamic Frequency Selection (DFS) test procedure document KDB 905462 D02 UNII DFS Compliance Procedures New Rules has been issued. 

The document describes the compliance measurement procedures for performing DFS tests under FCC Part 15 Subpart E Rules required for U-NII (Unlicensed –National Information Infrastructure) equipment that operates in the frequency bands 5250-5350 MHz and/or 5470-5725 MHz.

A U-NII network will employ a DFS function to detect signals from radar systems and to avoid co-channel operation with these systems. 

Section 6 provides the parameters for required test waveforms, minimum percentage of successful detections, and the minimum number of trials that must be used for determining DFS conformance.

One of the new requirements is for devices to detect a new radar waveform for DFS testing.  Historically, the FCC has required devices to detect 5 radar types. The new rules require detection of a 6th radar type which they designated as Type 1. A previous waveform which was designated as Type 1 is now called Type 0.  See the accompanying Table 5.

These rules became effective on June 2, 2014.  FCC has established a transition period:

  • New devices will be permitted to be approved until June 1, 2015 under the old rules
  • Starting June 2, 2016, all devices approved partially or completely under the old rules cannot be marketed, and permissive changes will not be permitted for devices approved under the old rules, unless they meet the requirements of the new rules

MET Labs has the capability to generate the new radar type using Agilent hardware coupled with custom software. Get tested to the latest DFS requirements on new products or update an existing product with a Class II Permissive Change.  Get a free quote now.

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