The Reference Point - Spring 2011 - (Page 8)

ISO Electrical Documents 13297 (a.c.) and 10133 (d.c.) What’s coming up? By John Adey T he ISO electrical documents have been under a several year review. The challenges and opportunities to harmonize with U.S. standards have created some interesting changes and benefits in the new draft standards. Although these documents are not slated for release for several months, this article outlines some of the major changes you can expect to see in both the a.c. and d.c. electrical documents. ISO Working Group 10 – Electrical…A bit of history Many of you may or may not be aware that since the mid 1990’s, ABYC has held the convenership of ISO Working Group (WG) 10. I recently took over the convenership from long-time ISO and ABYC member Ralph Lambrecht. Ralph had the distinction of having more ISO WG convenerships than any other person in the process, quite a position for an American in a foreign standards writing group! He had the history, the knowledge and the skills that make his shoes very difficult to fill. Fortunately, I had been able to work with Ralph as sort Original text Crafts earth Notable Change Main grounding/earthing point of a vice-chairman for the last several years. This gave me the opportunity to get to know the members, the issues and the nuances of running an ISO WG meeting. My personal thanks goes out to Ralph and I hope I continue his long standing tradition of excellence. The documents 10133 Small craft - Electrical systems - Extra-low-voltage d.c. installations (ISO 10133:2000) You will see that the current version of the d.c. electrical standards is from 2000. The versions that are in the final stages of the ISO process are the ones that will be discussed briefly here. The purpose of this article is to give you a heads-up regarding the changes the WG has made to the documents. Please do not make engineering changes based on what I offer here; rather, evaluate what you may have to consider as this document moves through the long process at ISO headquarters. Discussion The group has apparently always been confused by craft’s “earth.” We now have a common point, similar to ABYC. This change is made throughout the document. Like ABYC, the concept has been added to the document and additional overcurrent protection flexibility allowed. System – All components, conductors and power sources (e.g. batteries, charging sources) considered collectively, that provide, distribute and consume d.c. power. Like ABYC, 10133 now includes certain items that are required to have a 3% voltage drop: Panelboard mains, navigation lights and bilge blowers. Exceptions for self-limiting were added as stated above as well as tweaking the wording to match ABYC rules and exceptions. This is now the same as E-11. The screw can no longer bear directly on the conductor. TECHNICAL *Addition* Self limiting *Addition* Definition of a “system” 10% voltage drop Addition of a 3% voltage drop Overcurrent protection Now matches E-11 “Screw clamp” connections “Screw-clamp terminals or screwless terminal blocks shall clamp conductors to ensure reliable mechanical linkage and electrical contact is properly maintained without bearing directly on conductor strands” Overcurrent protection Drawings The 7”, 40” and 72” drawings were added from E-11 to clarify the location of the overcurrent protection. 8 Our Global Purchasing Directory is online at • the Reference Point • Spring 2011

Table of Contents for the Digital Edition of The Reference Point - Spring 2011

The Reference Point - Spring 2011
Letter from the President
Standards Week 2011
ISO Electrical Documents 13297 (a.c.) and 10133 (d.c.)
Marine Automation
Tall and Thin? Aspect Ratio and Your Rig
An Update on Educational Webinars…
The Kathy and Jerry Wood Foundation Supports ABYC Education
ABYC Foundation Update
Bulletin Board
Letter to the Editor
Welcome Aboard!
Long Range Planning Calendar
Index to Advertisers

The Reference Point - Spring 2011