Tag: NEC

Perkins School for the Blind. Courtesy: Fitzemeyer & Tocci Associates Inc.

Codes and Standards

Know the latest codes and standards for K-12 building design

Figure 1: A 1,000 hp, 460 V motor driven by a variable frequency drive. Courtesy: CDM Smith

Case study: Tips for replacing a motor or drive

Figure 1: A graph displaying the harmonics caused by a variable frequency drive and the resulting waveform. Courtesy: CDM Smith

Motors and Drives

Know the common design considerations regarding motors and VFDs

Figure 3: Example of paralleling switchgear with touchscreen interface and three generator control sections. Unseen are the hot-swappable, dual redundant programmable logic controllers. Courtesy: Kevin G. Reeves, CannonDesign

Emergency, Standby, Backup

Guidance on designing reliable mission critical power systems

Figure 6: Electric room sizes using the 2023 edition of the NEC are larger in design because clearances listed in Table 110.26(A)(1) need to be met plus the additional egress requirements when the doors of the electrical equipment are open. Courtesy: CDM Smith

Electrical and Power

Know how to size an electrical room properly

Figure 4: NEC Chapters 6 and 7 can be used together to properly design microgrids using renewable energy sources. Article 690 details the requirements of photovoltaic electrical energy systems, including arrays, inverters and controllers. Article 705 defines the connections to a primary source of electricity such as the utility grid. Articles 706 and 710 include guidelines for energy storage systems and their installation and operation as stand-alone systems. Courtesy: CDM Smith

Electrical and Power

What to know about NEC 2023 in electrical design

Figure 4: Simplified one-line diagram for a well station. Courtesy: CDM Smith

Case study: How to size circuitry for low-voltage motors at a well station

Figure 2: Motor branch-circuit protective device and motor starter installed in a motor control center bucket at a wastewater treatment facility. Courtesy: CDM Smith

Motors and Drives

Know the NEC design requirements for low-voltage motors

Figure 3: This Level 3 charger is properly protected from potential collisions by having bollards installed. Courtesy: CDM Smith

Electrical and Power

How to more meaningfully integrate EV charging infrastructure

Figure 2: ChargePoint products provided dual-port electric vehicle service equipment for a college campus project. Courtesy: SmithGroup

Electrical and Power

Case Study: Virginia Tech EV Charging Project Awarded Green Vehicles Credit