Yesterday, a young engineer was reviewing some drawings and noticed some drawings would reference a UPS (uninterruptible power supply) panel and others would reference an emergency panel. The question was simple; what is the difference between a UPS panel and an emergency panel?
A UPS is  define by the NEC as “a power supply used to provide alternating current power to a load for some period of time in the event of a power failure.” A UPS panel would then be defined as a panel board supplied with power from a UPS.
Emergency power refers to a situation where there is a backup power source for the normal power supply. Backup power may be derived from a second feed from the power company, an on-site generator, a UPS, etc. An emergency panel is a panel board serving as a distribution point for an emergency power system. The emergency power system would consist of at least 2 potential power sources, some form of transfer switch dictating which power supply is used, and the distribution equipment supplying the emergency power to the system.
Based on definitions, we can conclude that a UPS panel qualifies as an emergency panel. However, an emergency panel doesn’t always mean it is a UPS panel.

As a side note, not all emergency power systems are the same. Many will vary by the amount of time required to transfer to the emergency source, equipment capability, maintenance required, complexity of the system, etc.

-M