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Data Center Miscoordination: A Case Study

By Conduit

The NEC requires over current protective devices (OCPD) to protect cables from overheating and catching fire which is achieved using long-time (LT) breaker settings. The NEC also provides guidance on ground fault (GF) and ground fault delay (GFD) settings. Additional settings on OCPDs include long-time delay (LTD), short-time (SD), short-time delay (STD), and instantaneous (I), which can be adjusted and coordinated to protect personnel and equipment from dangerous fault currents. If the only goal was…

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Fit for Life? Avoid Equipment Failures

By Conduit

Fitness centers are busy at the start of each new year as people renew their commitments to health and fitness with the help of sophisticated electronic equipment such as treadmills, exercise bikes, and stair climbers. One such facility contacted us desperate for help with repeated electrical problems, including variable frequency drive (VFD) failures, fitness equipment control screens locking up and requiring frequent reboots, and physical damage to electronic components requiring replacement. Building managers frequently blame…

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HP&D Named Certified Commissioning Firm

By Conduit, HP&D in the News

Hood Patterson & Dewar (HP&D) is pleased to announce our status as a Certified Commissioning Firm (CCF). Organizations that hold the CCF designation stand out among competitors as experts – with the determination and ability to provide premier services to clients and the commitment to the advancement of the practice of commissioning. Established in 2002, the Building Commissioning Association (BCA) established the BCCB as a committee to oversee the process of creating a commissioning certification.    Established in 1982, HP&D is…

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Substation Safety: What Will You “Settle” For?

By Conduit

Hilton Mills, HP&D grounding specialist, was presenting at a technical conference about best practices for testing substation grounding systems. During his presentation, he stated that after a ground grid is freshly installed, it will take some time for the voids in the soil to compress, providing a good connection between the ground grid conductors and the soil. Immediately after installation, these voids can cause higher than designed (calculated) impedance, touch, and step values, which should…

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Hood Patterson & Dewar Named 2021 Commissioning Giant

By Conduit

For the third consecutive year, Hood Patterson & Dewar is pleased to be in the top tier of the 25 firms recognized on the Consulting-Specifying Engineer’s  2021 Commissioning Giants list. HP&D reported a commissioning revenue of $27.2 million. The magazine’s report is based on the annual commissioning revenue of firms of all levels, including new or existing buildings, whole building, recommissioning, monitoring-based, fire protection systems, building enclosure (envelope), emergency power systems, retro-commissioning, and communications systems….

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Hood Patterson & Dewar Opens Phoenix Regional Office

By Conduit

Hood Patterson Dewar (HP&D), a wholly-owned subsidiary of Patterson & Dewar Engineers, Inc., is pleased to announce its new office in the Phoenix area, located at 1525 North Hayden Road, Suite 100, Scottsdale, Arizona. This office gives HP&D a local presence and allows us to provide better service to our clients in the western region. The Phoenix office opened in July, with several tenured staff offering a wealth of knowledge and experience in electrical and…

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Conduit Bushings – Who Knew?

By Conduit

Conduit bushings play an important role in preventing damage to conductor insulation where the conductors pass through panelboard enclosures and tap box openings. Lately, we have seen numerous instances of plastic bushing inserts missing, displaced, or damaged, to the point where they no longer prevent the conductors from contacting the sharp edges of the equipment. The electricians were aware that the bushings were broken at one site but did not deem the situation important enough…

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Tales from the Script: What Is “Ready” in Commissioning?

By Conduit

Greenfield data centers are built the same way most other facilities are built: the building schedule is driven by constructability. From design through turnover, the primary and often the only driver is efficient, linear construction. While this makes perfect sense for most facilities, this traditional process leads to copious issues involving commissioning, schedule, and budget in a data center. The data center MEP equipment’s criticality creates a need for commissioning that far exceeds the typical…

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AJC Names Patterson & Dewar a 2021 Top Workplace

By HP&D in the News

Patterson & Dewar Engineers, Inc. (P&D) is pleased to announce it has been selected as one of the Atlanta Journal Constitution’s 2021 Top Workplaces. The Top Workplaces list is based solely on employee feedback collected through a survey administered by Energage LLC, a third-party employee engagement technology partner. The anonymous survey measures 15 culture drivers critical to an organization’s success, including alignment, execution, and connection. P&D is an employee-owned company, and as Mike Bryan, President…

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