In our top-to-bottom perspective of a photovoltaic (PV) system, we are still on the dc circuits from the PV array and are approaching the inverter. There are always a few details that get overlooked in designing, installing and inspecting these systems. The Conductors We have noted previously that single-conductor, exposed cables (type USE-2 or the [...]
With the eventual depletion of natural resources and the uncertain international situation, there is an increasing worldwide need for green, sustainable, energy efficient, stylish and affordable mechanical/electrical systems. Of the three disciplines now regulated by the national ASHRAE / IESNA / ANSI1 Standard 90.1 (the United States’ energy standard for other than low-rise residential buildings, [...]
Significant growth in optional standby systems for commercial applications is being driven by the demand for electrical power to be present that will ensure continuity of business activities. Concerns stem from weather related outages to other reliability issues that can result in the loss of electric utility of a building, communication center, or process. Loss [...]
The East Bay Uniform Code Committee (EBUCC) is currently accepting applications for the W. Creighton Schwan scholarship. A scholarship in the amount of $1,000 has been established in his name for a deserving student with a desire to pursue a career in the electrical field. Attached you will find additional info on Creighton as well [...]
Next year we will commemorate the fortieth anniversary of the U.S. Department of Labor Occupational Safety and Health Administration (OSHA). Since its creation, overall workplace fatalities have been cut by more than 60 percent and occupational injury and illness rates have declined by 40 percent. All of this occurred during an era of unprecedented growth [...]
Rule 36-110 refers us to Canadian Electrical Code Table 33, Horizontal Clearances from Adjacent Structures, and to Table 34, Vertical Clearances for Overhead Lines, to provide minimum safety clearances for installations operating in excess of 750 volts. Table 33 provides minimum horizontal clearances between high voltage conductors and buildings. Table 34 provides minimum ground clearances [...]
There are some subjects in the Canadian Electrical Code that often become a source of heated discussions by the users. Selection of dry type transformers and selection of a proper rating of the transformers’ circuits is one of such controversial subjects. So, let’s try to clarify this seemingly complex issue. First of all, we need [...]
In the March/April issue of the IAEI News, I was wondering what our administrators were thinking about when they were downsizing or, in some cases, eliminating the inspection services that provide for the safety and welfare of their constituency. This time, I am wondering what we can do as inspectors, installers, designers, manufacturers, etc., to [...]
Question: Luminaire disconnects and motors? Are the luminaire disconnect connectors that are used to comply with NEC 410.130(G) evaluated for other uses such as a disconnecting means for a motor?
Question: Presentation on how to use UL White book? I received a UL White Book at an IAEI meeting. It seems to contain a wealth of information for electricians and electrical inspectors; however, I do not know how to use it. Does UL have an online presentation that can show me how to use the [...]
Question: Grounding permanently mounted portable luminaires Are permanently mounted portable luminaires required to be grounded? I have seen some wall-mounted portable luminaires that are cord connected with a polarized plug, even though these products often have quite a bit of exposed metal.
Quincy, Mass. – The National Fire Protection Association (NFPA) is kicking off National Electrical Safety Month (May) by reminding the public to be aware of the risks associated with the use of electricity, and providing safety tips to assist individuals in taking steps to reduce the risk of experiencing a home electrical fire. In recent [...]
