Emergency Stop! What’s the latest?

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November 28, 2017

Emergency Stop and Maintenance Requirements at Fuel Stations

Emergency Stop switches are nothing new for fuel installations. They have been required for years as a safety feature for customers and operators of these facilities. That being said, the requirements for the operation of these E-Stops has changed over the last few years as the Electrical code has evolved.

The full text of the actual section of code is at the end of this blog.  The simple explanation of the requirements is that ALL power and communications to the fueling must be disconnected when the emergency stop is activated. This latest code revision has also added that all power to remote pumps (submersible pumps) at the tanks must be removed as well as power at the islands.

Many e stops in the past have utilized a “Fuel Only” sub panel that was fed by a shunt trip breaker. The problems with that are the communication wires are not disconnected and the grounded conductor (Neutral) is not disconnected either. In another scenario some homemade systems used normally closed relays that when energized took power away from the dispensing equipment. The trouble with that is the breaker for the e-stop could be turned off and it would never operate when you needed it to, leaving the fuel system energized in an emergency.

Maintenance Switches Required:

The NEC also requires maintenance switches that allow all power and communications to be disconnected from a dispenser for maintenance. The switch must also be lockable. Turning off and locking out the circuit breaker is no longer sufficient.

The best way to make sure your emergency stop system meets the current code it to install a UL approved system that takes the latest codes into consideration.

Fatboy Electric has designed a system that meets these codes. It is UL508a approved and built right here in Kansas City, MO USA. Contact us for specs and pricing on a system for your next project.

Here is the current 2017 NEC code related to E-Stops:

2017 NEC 514.11

A – Emergency Electrical Disconnects. Fuel dispensing systems shall be provided with one or more clearly identified emergency shutoff devices or electrical disconnects.  Such devices or disconnects shall be installed in approved locations but not less than 6m (20 ft) or more than 30 m (100 ft) from the fuel dispensing devices that they serve.  Emergency shutoff devices or electrical disconnects shall disconnect power to all dispensing devices: to all remote pumps serving the dispensing devices: to all associated power, control, and signal circuits; and to all other electrical equipment in the hazardous (classified) locations surrounding the fuel dispensing devices.  When more than one emergency shutoff device or electrical disconnect is provided, all devices shall be interconnected.  Resetting from an emergency shutoff condition shall require manual intervention and the manner of resetting shall be approved by the authority having jurisdiction.  [30A:6.7]

Exception:  Instrinsically safe electrical equipment need not meet this requirement.  [30A:6.7]

B – Attended Self-Service Motor Fuel Dispensing Facilities. At attended motor fuel dispensing facilities, the devise or disconnects shall be readily accessible to the attendant. [30A:6.7.1]

C – Unattended Self-Service Motor Fuel Dispensing Facilities. At unattended motor fuel dispensing facilities, the devices or disconnects shall be readily accessible to patrons and at least one additional device or disconnect shall be readily accessible to each group of dispensing devices on an individual island.  [30A:6.7.2]

514.13   Provisions for Maintenance and Service of Dispensing Equipment.  Each dispensing device shall be provided with a means to remove all external voltage sources, including power, communications, data and video circuits and including feedback, during periods of maintenance and service of the dispensing equipment.   The location of this means shall be permitted to be other than inside or adjacent to the dispensing device.  The means shall be capable of being locked in the open position in accordance with 110:25


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