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Tom Divine, PE, Senior Electrical Engineer, Johnston, LLC

Tom Divine, PE, LEED AP

Articles

Figure 5: Unit equipment in the corridor of a residential occupancy. This unit is normally not illuminated and automatically comes on when normal power fails. Courtesy: Johnston, LLC
Case Study March 19, 2025

Case study: How to meet code and forgo emergency lighting outages

An existing residential facility in Texas added a standby generator to serve its entire load during utility outages.

By Tom Divine, PE, LEED AP
Figure 3: Artist's conception of an exit sign using a pictogram. The pictogram is called "Running Man," and is commonly used in Europe, where the diversity of language is much greater than in the United States. Under NFPA 101, similar pictograms may appear on exit signs in the United States with authority having jurisdiction approval. Courtesy: Johnston, LLC
Lighting and Lighting Controls March 5, 2025

Do you know the requirements for emergency lighting systems?

Emergency lighting requirements derive from provisions of various building codes. Requirements are complex and can be difficult for an electrical engineer to locate in the heat of battle.

By Tom Divine, PE, LEED AP
Electrical and Power July 19, 2022

Your questions answered: How to design electrical distribution systems

In the webcast “How to design electrical distribution systems,” some items were left unanswered. Tom Divine tackles several here

By Tom Divine, PE, LEED AP
Codes and Standards December 29, 2020

Understanding the changes to NFPA 70-2020

New requirements of the 2020 edition of the National Electrical Code will affect facility design

By Tom Divine, PE, LEED AP
Electrical and Power July 29, 2020

Back to basics: Switchgear, transformers and UPSs

Switchgear, transformers and uninterruptible power supplies are among the largest, costliest and most critical devices in a facility

By Tom Divine, PE, LEED AP
Healthcare Facilities June 19, 2020

Basics of NFPA 99 changes for hospital design

How engineers should navigate the changes to the 2018 edition of NFPA 99

By Tom Divine, PE, LEED AP