NFPA Requirements For Electrical Disconnects

To disconnect or not to disconnect?

By Jim Rocco

Want to know more? Read the unabridged version of this article with even more information about NFPA requirements here.

The National Fire Protection Association (NFPA) Code for Motor Fuel Dispensing Facilities and Repair Garages (NFPA 30A) provides requirements for both emergency electrical disconnects and maintenance electrical disconnects. After speaking with a number of contractors, suppliers and marketers about the electrical disconnects, there seems to be no agreement on what electrical circuits are controlled or should be controlled by these electrical disconnects.

Emergency Electrical Disconnects
The current (eighth) edition of NFPA 30A (NFPA 30A-2008) provides the following requirements for emergency electrical disconnects in Section 6.7:

In addition to disconnecting the power to the dispensers and remote pumps, this provision requires that the power be disconnected to “all associated power, control and signal circuits.”

In a recent survey conducted by PEI, respondents were split 50/50 on whether existing emergency electrical disconnects are thought to meet the requirements of Section 6.7 of NFPA 30A-2008. All responses identified the AC circuits, including lighting and dispenser power and remote pumping controls and DC circuits for dispenser control, as circuits that were part of the emergency electrical disconnect. Intercom and other data-related circuits associated with such devices as credit card readers, cash acceptors, containment sump monitoring devices, video displays and Internet-accessible monitors, however, were typically not identified separately. The confusion seems to be whether these circuits are included in the scope of the emergency electrical disconnect requirements as “associated power, control and signal circuits;” whether the circuit can be disconnected between the dispenser and the control; or whether the power to the control itself needs to be disconnected.

This leads me to question whether the current language associated with the emergency electrical disconnects adequately describes the electrical circuits that should be disconnected. Have the devices and accessories on today's dispenser islands evolved beyond the original scope of this provision? If so, what revisions should be made? What is included in “all associated power, control and signal circuits” and “all other electrical equipment”? Are there any circuits besides intrinsically safe circuits that should be specifically excluded from these requirements?

As newer facilities have become larger, the matter of how many disconnects should be installed and their location in light of the minimum and maximum distance requirements seems to require clarification. Should the provisions address specific locations of emergency electrical disconnects, i.e., in close proximity to an attendant or exterior to a building in close proximity to a customer? Should the separation distance be greater than 100 feet? Where fuel islands are remote from one another, should a single electrical disconnect be provided to disconnect power to multiple fueling areas if there is an emergency on one of them?

Maintenance Electrical Disconnect
The maintenance electrical disconnect is intended to disconnect the power to an individual dispenser or group of dispensers during maintenance activities. The maintenance electrical disconnect is generally in the back room of a facility and accessible only to employees or service contractors. The current edition of NFPA 30A (NFPA 30A-2008) provides in Section 6.3.6(2) that:

Again, there seems to be a considerable difference of opinion as to what power should be disconnected, how and when. Some service contractors indicated that disconnecting the electrical power as described in this provision can be done at some facilities only by essentially shutting down the entire fueling operation.

Numerous Questions To Explore
Is the intent to ensure that the flow of motor fuel through a dispenser cannot occur while working on a dispenser, or is it also intended to include elimination of all potential ignition sources while working on a dispenser? What are the activities that may cause “an accidental release or ignition source”? Clearly, working on the piping within or connected to the dispenser or replacing a hose, nozzle, filter or circuit board in a dispenser would trigger this provision. Depending on how broadly this provision is interpreted, replacing a nozzle could require that all other dispensers associated with a remote pumping system be taken out of service.

The requirement for disconnecting the power at the main electrical disconnect panel seems to be a reference to the circuit breakers in the electrical panel. Most isolation controls for dispensers are a group of relays between the main electrical disconnect panel and the dispenser. These isolation controls are designed to disconnect the power and neutral lines to the dispenser and controls. It is unclear whether this provision precludes the use of relays or other isolation-type controls to control groups or individual dispensers. How is this different than the electrical code dispenser isolation? Or different from OSHA lockout/tagout requirements?

The extent of “all associated control circuits” is unclear. Does this refer only to controls that could authorize flow of product, such as the point of sale device? Or is it intended to more broadly disconnect ancillary devices, i.e., electronic line leak detectors, that interact with the remote pumping systems, or credit card readers or intercoms that are integrated into or adjacent to the dispenser? Is it intended to be as broad as the requirements under the Section 6.7 emergency electrical disconnect provisions or limited to primary circuits that control the flow of motor fuel?

Want to know more? Read the unabridged version of this article with even more information about NFPA requirements here.

As the National Fire Protection Association Technical Committee on Automotive and Marine Service Stations moves through the next revision cycle for NFPA 30A, these questions must be addressed. It is important for the committee to understand the complexities of complying with these requirements and the potential alternatives, as well as the similarities and differences between the electrical disconnect and dispenser isolation and lockout/tagout provisions of other codes. Comments concerning this issue would be greatly appreciated.

Bob Benedetti, NFPA's principal flammable liquids engineer, has volunteered to collect and summarize comments for the committee. You can submit comments to Bob via e-mail at bbenedetti@nfpa.org.

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The PEI Journal • First Quarter 2009 • Volume 3, No. 1 • Contents are Copyright © Data Key Communications, Inc.
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