Utilizing Code 700.3F in the Design Process

If the emergency system relies on a single alternate source of power, which will be disabled for maintenance or repair, the emergency system shall include permanent switching means to connect a portable or temporary alternate source of power, which shall be available for the duration of the maintenance or repair.

Code 700.3 (F) is a provision in NFPA’s 2017 National Electrical Code for legally required systems. To put it simply, when a permanent generator is under maintenance or repair, a permanent switching mechanism needs to be installed for portable generator hookup. The added importance of this provision is the code requires the secondary system to be permanently connected, making this requirement an important aspect early in the design process.

 Informational Note: there are many possible methods to achieve the requirements of 700.3(F). See figure 700.3(F) for one example.

700.3(F) Considerations Into The Design Process
  • The connection to the portable generator shall not require modification of the permanent wiring system.
  • Transfer of power between the normal and emergency sources shall not exceed 10 seconds.
  • The interlocking shall prevent inadvertent interconnection of power sources.
  • The switching means shall include a contact point that will annunciate at a location remote from the generator indicating the permanent energy source is disconnected from the emergency system.
  • It is permissible to utilize manual switching from the permanent source of power to the portable source of power and to utilize the switching means for the connection of a load bank.
We have you covered

The simplest way to comply with this code is a manual transfer switch that will transfer between the permanent generator and a set of Cam-Loks located in the manual transfer switch enclosure. This will allow the temporary generator to be plugged in and connected.

We have a range of options and customizations to meet these requirements and best suit your project needs.

  • We work directly with Onsite Power Inc. (Thomson Power Systems), ASCO Power Technologies (Quick Connect Power Panel), Trystar (Dual-Purpose Generator Docking Station/Manual Transfer Switches) and others to get you the right product quickly and cost-effectively.
  • Not only can we provide power distribution equipment sales but specialized teams of service, parts, rentals, and emergency 24/7 response teams as your single resource for generator systems.
  • With over 30 years of experience, we have the knowledge, skill, and professionalism to deliver on all of your project needs.
We’ve got you covered 24/7 365 call Gen-Tech today (800)-625-8324
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