• 100 Definitions
• 220.70 Energy Management Systems (EMS)
• 705.13 Power Control Systems
• 750 Energy Management Systems
• 750.6 Listing

Systems that meet the new definition of an energy management system must comply with the requirements found in Article 750 when used as permitted in the following sections:

220.70

Load calculations are permitted to take advantage of an energy management system when sizing feeders, service conductors, and equipment. If an energy management system (EMS) such that current to a feeder or service is limited and when the EMS is in accordance with 750.30, the setpoint value for maximum amperes current is permitted to be used for the load calculations. The current value used must be considered to be a continuous load.

705.13

The previous edition of the NEC included details that were more appropriately located in Article 750 Energy Management Systems. Section 705.13 Energy Management Systems (EMS) now points to 750.30 with permissions to leverage the setpoints of the EMS to limit current and size equipment based on this setpoint value.

The new definition of an EMS found in Article 100 helps the user of the Code to understand that an EMS consists of any of the following:  

    • Monitor(s)

    • Communications equipment

    • Controller(s) 

    • Timer(s)

The listed devices, or other device(s), must monitor and/or control an electrical load or a power production or storage source.

When an installed system meets the definition of an EMS, it must comply with Article 750 Energy Management Systems. This article has important requirements including the following:

Section 750.6 includes listing requirements ensuring that EMSs be one of the following:

    · Listed as a complete energy management system

    · Listed as a kit for field installation in switch or overcurrent device     enclosures

    · Listed individual components assembled as a system

In addition, 750.20 includes requirements to make certain that the EMS does not override any control necessary to ensure continuity of an alternate power source for:

    · Fire pumps (695)

    · Healthcare facilities (517)

    · Emergency systems (700)

    · Legally required standby systems (701)

    · Critical operations power systems (708)

220.70 is a new section recognizing the impact an energy management system can have when the EMS is used to limit the current ot afeeder or service in accordance with 750.30. The new requirement notes that you must based the calculation on a single value that is equal to ther maximum ampere setpoint fo the EMS and it must be considered a continuous load.

705.13 was modified to point to 750.30 for details on the energy management system.  

Article 100 now includes the definition of the term energy management system which used to be a part of 750.2. The definition did not change the existing definition but now it’s location in Article 100 must be recognized to ensure it is not missed.  When an installed system meets the definition of an EMS, it must comply with Article 750 Energy Management Systems. 

Article 750 had various changes made including the following:

Section 750.6 includes listing requirements ensuring that EMSs be one of the following: 

    • Listed as a complete energy management system 

    • Listed as a kit for field installation in switch or overcurrent device enclosures 

    • Listed individual components assembled as a system 

In addition, 750.20 includes requirements to make certain that the EMS does not override any control necessary to ensure continuity of an alternate power source for: 

    • Fire pumps (695) 

    • Healthcare facilities (517) 

    • Emergency systems (700) 

    • Legally required standby systems (701) 

    • Critical operations power systems (708)