Exposed electrical motor connection splices

April 2, 1996

Mr. Henry J. Smahlik
Director of Safety and Health
[Recipient address omitted]
Dear Mr. Smahlik:

This is in response to your September 25, 1995, letter to Mr. Joseph Pipkin, Director of the Office of Electrical, Electronic and Mechanical Safety Standards. In your letter, which was forwarded to this office for disposition, you requested an interpretation of the electrical standard, 29 CFR 1910 Subpart S. Please accept our apology for the delay in responding. Your scenario and question and our reply follow.

Scenario: During a safety inspection of a workplace, some electrical motors (called "DC Mill Motors") were observed as not being equipped with covers (junction boxes) over the electrical connections where the motor wiring connects with the facility wiring. The wiring connects outside of any house or junction box, and, when installed, is covered with electrical tape. The voltage to the motors is in excess of 110 volts. The motors are easily accessible to plant personnel. The ratings of the motors range from 5 to 3000 horsepower.

Question: Is the wiring connection described in the scenario above in violation of the aforementioned electrical standard?

Reply: Yes. An electrical conductor splice connection point must be quarded by approved cabinets or other forms of approved enclosures or by any of the means required under paragraph 1910.303(g)(2). Otherwise, the method you described of electrical-tape-covered connection of motor wiring to the facility wiring would be a violation of the aforementioned standard. Sections 300-15 and 370-28 of the 1996 National Electric Code (NEC) requires a box to be installed at each conductor splice connection point, outlet switch point, junction point, or pull point for the connection of conduit, electrical metallic tubing, surface raceway, or other raceways.

Section 370-28 requires that all pull boxes, junction boxes, and conduit bodies be provided with covers compatible with the box or conduit body construction and suitable for the conditions of use. When an employer meets this NEC standard and uses a box which is an approved enclosure as noted above, it would comply with paragraph 1910.303(g)(2). A copy of these NEC standards and other OSHA standards are enclosed for your use.

We appreciate your interest in occupational safety and health. If we can be of further assistance, please contact the Office of General Industry Compliance Assistance [at (202) 693-1850].

Sincerely,

John B. Miles, Jr., Director
Directorate of Compliance Programs

Enclosures

[Requester letter reproduced on OSHA page; omitted here.]