Signs of the Times - January 2014 - (Page 30)

Lig hti n g T e c hn i ques By Marcus Thielen UL's Mandated Hazards Marcus Thielen is a physicist and lighting-industry consultant from Duisburg, Germany Technological advances make testing dangerous. H ere's some sobering irony. Allegedly, the entire purpose of Underwriters Laboratories (UL) is to ensure safety. However, due to technological advances, UL 48's mandated testing procedures (Parts 31-37) have now become dangerous in some cases. As often stated, the road to hell is paved with good intentions. Because most hazards presented by electricity and electrical equipment are not obvious or easily visible, early in the history of society's electrification, groups of specialists - like UL and the National Fire Protection Assn. (NFPA) - appropriately established regulations for making electrical equipment safe. The National Electrical Code (NEC) and the UL document series would follow. To make newly built electrical equipment safe, it must be inspected and tested before being put in use (and in the hands of "dumb" users). This also applies to electric signs. For the electric signshop, it's mainly "UL 48 - Electric Signs" Photo 1: An electronic fluorescent lamp ballast. The red circle indicates the capacitors across the line, and the blue circle shows the capacitors to ground of the RF line filter. The schematics are similar to those in Fig. 1. (ISBN 1-55989-974-3). The first edition was published in November 1917, 11 years after the first edition of ST. Still today, even if construction sections are observed, performance Fig. 1: Typical input circuit of an electronic, fluorescent lamp ballast. Note the rated voltages for the capacitors across-the-line and to ground (red circles). 30 SIGNS OF THE TIMES January 2014 tests (Parts 31-38) must be carried out. Especially with large or unique signs that are built onsite, admin-

Table of Contents for the Digital Edition of Signs of the Times - January 2014

Signs of the Times - January 2014
ST Update
Technology Update
Large-Format Design Strategies
Vinyl Apps
Strictly Commercial
Lighting Techniques
The Moving Message
Technology Review - Agfa’s Jeti Titan X
Technology Review - Polytype’s NQ32 UV hybrid printer
Design Matters
New Products
Industry News
GableSigns’ Casino Signs
Dynamic Digital Signage Made Simple
Building Street Cred
Modern Sign Engineering
Advertising index
Editorially speaking

Signs of the Times - January 2014