At the 2011 ASHE Conference, we gained some very interesting and important information regarding the National Electrical Code requirements for healthcare facilities. We wanted to share this with you and hope you find the article below helpful when considering the design of your next healthcare project.
Mark Fratto, P.E., LEED AP
NFPA 70 (the National Electrical Code) requires that the electrical distribution system in a healthcare facility be coordinated. In other words, the circuit breaker or fuse closest to the load should interrupt power to a failed device instead of a circuit breaker or fuse that would take an entire electrical panel or part of the hospital off line. Obviously this makes sense, especially in a healthcare facility. However, the code leaves room for interpretation on the parameters associated with the coordination analysis.
Some of you may have experienced local authorities interpreting the National Electrical Code to require system coordination at 0.01 seconds in lieu of the 0.1 second standard that has existed for some time.
The 0.01 second requirement requires a more complex and more expensive electrical system with larger equipment. This has resulted in higher construction costs and larger electrical rooms. In addition, it can increase the incident arc flash energy which increases maintenance costs. For these and other reasons, many states have clarified the code to only require the standard 0.1 second coordination. However, at this time, Texas has not issued that clarification and is leaving the interpretation up to local electrical inspectors.
During the July 2011 ASHE Conference in Seattle, we were informed that the NFPA 99 committee has reviewed this issue at length and the 2012 NFPA 99 will make it clear that systems can be designed for 0.1 second coordination.
For now, we would recommend that you discuss this issue with the local electrical inspector prior to starting the design of any healthcare project.
For more information regarding this issue, please contact us at (817) 461-2337.