Summarizing NEC 2017 Changes
Standards can be confusing! In the North American machine marketplace, the key standards are UL508, NFPA79 & NFPA70 (National Electric Code). Below are some key changes that are being required with the latest version of NFPA70 (National Electrical Code) 2017.
Short Circuit Current Ratings (SCCR):
The NEC 2017 edition increases awareness of the proper application of electrical distribution equipment with regard to SCCR and expands the types of equipment that require SCCR marking.
Mandatory Equipment SCCR Marking:
- 409.110(4) Industrial Control Panels
- 430.8 Motor Controllers
- 430.98 Motor Control Centers
- 440.4(B) Air Conditioning & Refrigeration Equipment
- 620.16(A) Elevator Control Panel
- 670.3(A)(4) Industrial Machinery
- 700.5(E) Transfer Equipment for Emergency Systems
- 701.5(D) Transfer Equipment for Legally Required and Standby Systems
- 702.5 Transfer Equipment for Optional Standby Systems
- 708.24(E) Transfer Equipment for Critical Operations Power Systems.
Requirements for Equipment SCCR to be Greater than the Available Short Circuit Current:
- 110.10 Circuit Impedance, Short-Circuit Current Rating, and other Characteristics
- 409.22(A) Industrial Control Panels
- 440.10(A) Air Conditioning & Refrigeration Equipment
- 620.16(B) Elevator Control Panels
- 670.5(1) Industrial Machinery
Available Short-Circuit Current:
The proper application of electrical equipment includes rating the equipment to handle available short-circuit current levels and marking that level on the equipment after installation.
- 110.24 Service Entrance Equipment
- 409.22(B) Industrial Control Panels
- 440.10(B) Air Conditioning & Refrigeration Equipment
- 620.51(D)(2) Elevator Control Panels
- 670.5(2) Industrial Machinery
Surge Protection:
For increased protection and reliability, the NEC 2017 expands requirements for safety-related circuits. Surge protection is required for fire pump controllers, critical operations data systems, industrial control panels, including machinery with safety interlock circuits, and disconnects that supply emergency system loads. Updates include:
- 620.51(E) – Surge protection is now required where any of the disconnecting means for elevators, dumbwaiters, escalators, moving walks, lifts and chairlifts have been designated as supplying an emergency system load.
- 645.18 – New requirement for surge protection in critical operations data systems.
- 670.6 – Surge protection is now required for industrial machinery with safety interlock circuits.
- 695.15 – A listed surge protective device must now be installed in or on fire pump controllers.
Looking for the latest version of NFPA 70, Check out their website.
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