Christopher Dent, PresidentDENT Instruments, Inc.

NEMA Submetering WorkshopRosslyn, VA May 21, 2014

1. Safety UL (Broadly – the NRTLs) International (IEC, CE) Other Regulators (FCC)

2. Certification ANSI IEEE IEC

3. Consumer Confusion Metering Terms “Revenue Grade” ANSI Self-Certification vs. Independent

Certification

A Listed device can be used by itself, a Recognized device cannot be used by itself and requires some other device to make it whole or useful (e.g., an enclosure around a Recognized meter board)

Meters must be UL Listed to UL61010-1but…

CT’s can only be UL Recognized to UL61010-1 and cannot be UL listed because a CT “is useless by itself” Wha?!

Therefore, Listed meters must specify in their UL report the recognized CT’s they will use

Our list of critical components for meters from UL specifies the only recognized 6101 CTs that we can use. ($2k to add an already recognized CT to our report; ~$10-16k if not recognized)

We need 61010 UL LISTED CTs that can be used on anybody’s meter!

UL 2808 (Subject, and later) listing coming; But, we need 61010 for use outside the US

UL 508 Panel Shops are not allowed to use UL recognized meters in their enclosures if they contain built-in power supplies (e.g., a bare meter board) even though the only difference between the UL recognized meter and the UL listed meter is that the UL listed meter is inside an enclosure!

UL does not recognize other NRTLs Panel shops have been told they will lose

their UL Certification if they use components listed by other labs (e.g., Intertek ETL)

Manuals must contain wording similar to: “The UL listing covers the use of the following DENT Instruments CTs that are UL Recognized and have been evaluated to IEC 61010-1 (list) The use of any other CT will invalidate the UL Listing of the (meter).”

This prohibition includes CTs listed by other NRTLs including ETL, CSA, TÜV – even when tested to the same 61010-1 standard!

Ah, whither thou ANSI C12.16-1991? Now removed, it was the only standard written for electronic meters

ANSI C12.1 and 12.20 have 39 Tests including effect of Tilt and Register Friction

ANSI C12.x is not written for CT meters that can accept a variety of CTs with different Full Scale amperage ranges. It is written for ‘this is a 100A meter, that is 200A meter’

C12.x is not made for removable CTs Some meters can compensate for ratio and

phase shift errors and make an ugly CT look good

Even though ANSI C12.1-2013 is to be released soon, rumors state the changes are minor and are still not geared to electronic meters

IEEE C57.13 is for CTs only; and has 1.2%, .6%, .3% Accuracy Thresholds vs. ANSI 1%, .5%, and .2%

ANSI is (probably?) an “end to end” accuracy specification, but…

Wouldn’t it be nice if we could use any CT with any meter?

We need Harmonizing of ANSI & IEEE & IEC (Europe et al… and IEC 60044-1 for CT accuracy)

Need a global accuracy standard (I’m dreaming)

There is only one 3rd party lab (Met labs) that can test to ANSI C12.x (even though OSHA states UL and TÜV are recognized to test to ANSI C12.1, we cannot find anyone in their companies that know anything about ANSI certification.)

Leads to monopoly pricing We need more independent (Accuracy)

Certification testing laboratories

We need a standard definition of power terms

For example, DENT Instruments defines:+PF as lagging and -PF as leading+ kW as power into the load (away from the

grid) and –kW from the load (to the grid)“System” Amps are the average of 3

phases, etc.

We need standardized accuracy terms:“Revenue Grade”ANSI Self-CertificationANSI Independent Certification

Matching CT Accuracy (IEEE C57.13) to Meter Accuracy

We need an Accuracy/ANSI-like standard for modern electronic meters – best if global

Take UL down a notch …or 20! Increase competition of Certification Labs Harmonize the interplay of various agencies –

NRTLs (UL, ETL...), OSHA, NEC, etc. Who should lead the effort? Who should be

involved? In what way(s)? Create an ‘Association of Meter Providers’

(AMP!) AMP stamp/certification?