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Illustrated Catastrophes

Nov 1, 2007 12:00 PM, By Joe Tedesco, NEC Columnist

More Code catastrophes

As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without criticizing anyone or any product, the following scenarios present us with serious safety questions.

All references are based on the 2005 NEC.

THROUGH THE LOOKING GLASS

I found this installation in a major U.S. airport. The disconnect for this equipment is visible, but is not readily accessible because it's located behind a window. The following Code section applies to this installation.

“440.14 Location. Disconnecting means shall be located within sight from and readily accessible from the air-conditioning or refrigerating equipment. The disconnecting means shall be permitted to be installed on or within the air-conditioning or refrigerating equipment.

“The disconnecting means shall not be located on panels that are designed to allow access to the air-conditioning or refrigeration equipment.

“Exception No. 1: Where the disconnecting means provided in accordance with 430.102(A) is capable of being locked in the open position, and the refrigerating or air-conditioning equipment is essential to an industrial process in a facility with written safety procedures, and where the conditions of maintenance and supervision ensure that only qualified persons service the equipment, a disconnecting means within sight from the equipment shall not be required. The provision for locking or adding a lock to the disconnecting means shall be permanently installed on or at the switch or circuit breaker used as the disconnecting means.”

TRANSITION TROUBLE

I was surprised to learn someone who services this type of equipment everyday installed this arrangement. The transition from one wiring method to another was not one that was designed for this use. Here's how the NEC applies in this situation.

“300.15 Boxes, Conduit Bodies, or Fittings — Where Required.

“Fittings and connectors shall be used only with the specific wiring methods for which they are designed and listed.

“(F) Fitting. A fitting identified for the use shall be permitted in lieu of a box or conduit body where conductors are not spliced or terminated within the fitting. The fitting shall be accessible after installation.”

Found a Code violation? E-mail your text and photos (no cell phone images please) to Joe Tedesco at joetedesco@comcast.net

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