Aug 07, 2019
New for the 2017 code cycle is section 330.15, entitled “Metal-Clad Cable: Type MC Exposed Work.” This new Code section requires an exposed run of MC Cable to closely follow the surface to which it is mounted while enjoying a new permission that allows the MC cable to be installed on the underside of floor joists.
Jul 02, 2019
There is an old joke among HVAC contractors. When bidding on a replacement system for a customer, step back 100 feet from the house and hold up your hand. If three fingers will block the view of the house, install a three-ton unit. If it takes four fingers to block the view, then install a four-ton unit. That meager attempt at humor does highlight an issue that has been kicked around since the beginning of the industry. Are load calculations necessary? If so, how do you properly size a heating and air conditioning system for a house or commercial building?
Jul 02, 2019
Prior to the 2017 edition of the NEC, 120-volt receptacles equipped with USB charging outlets had not been addressed by the National Electrical Code. Universal Serial Bus (USB) connections have been around since the 1990s and are widely used to charge portable devices and computer peripherals, as well as transfer data.
Jul 02, 2019
It is no surprise that Ground Fault Circuit Interrupter protection has again been expanded in the 2017 edition of the National Electrical Code. Since its inception in the 1971 edition, GFCI coverage has been expanded and tweaked with just about every code change. In this edition, coverage has been increased in several significant ways, but an important clarification has also taken place. Specifically as regards protection for 15 and 20 amp outlets near sinks, the point at which the measurement is taken as well as the method to be used to measure the 6-foot distance has been clarified.
Jun 28, 2019
Massachusetts electrical licenses expire on July 31, 2019. The Massachusetts Board of State Examiners of Electricians requires licensees to complete 21 hours of electrical continuing education every 3 years in order to renew their license. If you did not successfully renew your license in 2016, and your license expired July 31, 2016, make sure to complete your continuing education and renew your license now! If your license expired July 31, 2016 and you do not renew by July 31, 2019, you will lose your license and will need to re-test to become licensed again.
Jun 05, 2019
Back in the rural south, around 1940, power companies would mail flyers to their customers at the beginning of summer. These flyers would give tips on how to stay cool during the hottest days ahead. Some of the tips were; grow ample shade around your residence, stay inside during the hottest part of the day, use open windows for increased air circulation, and keep wet towels available to cool your forehead and neck. Homes, in those days, were designed to facilitate air movement. Large porches and arched ceilings in hallways enhanced air currents that moved freely through the structure. These conditions were the norm for homeowners before the availability of affordable air conditioning.
Jun 05, 2019
Ground fault protection is not new, having been introduced in the 1971 edition of the National Electrical Code. GFCI devices have saved many lives since then by preventing shock and electrocution. As you may know, they contain a small transformer that detects current leakage from the phase to the grounded (neutral) conductor. That is why they work even in circuits that do not have a separate grounding conductor. These devices are designed to interrupt current when the leakage reaches a threshold of 4 to 6 mA, just shy of the amount of current that can cause injury to the human body.
Jun 05, 2019
The 2017 NEC now requires meeting rooms measuring 1,000 square feet or less to be equipped with 125-volt 15 or 20 ampere receptacles. This new requirement will help serve today’s trend that requires we travel with a myriad of electronic devices to meet our daily personal and business needs. This new Code-reference, 210.71 Meeting Rooms, is found in Article 210 Branch Circuits, Part III. Required Outlets, and is only applicable to meeting rooms or areas measuring 1,000 square feet or less. The qualifying room or area is to be determined by measuring wall-to-wall space, as well as space created using movable partitions.
