This Marne and Associates NESC and OSHA Newsletter addresses issues relevant to power and communication utilities. Often, our experts also answer questions from utility professionals regarding the NESC and OSHA. Send an email to kirstin@marneassociates.com with a concise description of your NESC or OSHA question. We attempt to answer every question received, but the volume and type of questions limits us.

In This Issue:

• Question 1: Exception to Joint Use Clearances for Service Drops
• Question 2: Arc Flash Hazards
• Upcoming Events

Is there any clearance reduction from 40 in at the transformer pole between the secondary power and communication service drops?

I believe you are referring to Exception 3 to NESC Rule 235C1. Exception 3 allows the clearance of power service drops (0-750 V) runnning above and parallel to communication service drops to be reduced to 12 in at any point in the span including the point of attachment to the building or structure being served. This exception only applies in the span and at the service. The required clearance of 40 in at the pole between the power secondary (0-750V) and communication cables must be maintained. See Figure 1 below.

Fig. 1 - Exception 3 to NESC Rule 235C1

What level of arc rated clothing do we need to provide for the linemen?

NESC Rule 410A3 requires that all utilities assess the potential exposure of employees to electric arcs and provide the proper arc rated clothing by January 1, 2009. The amount of arc energy is dependent on the available fault current, the duration of the arc, and the distance from the arc to the employee. Since the available fault current and the time for the system protection to de-energize the line during a fault vary from system to system and from location to location, each utility will have different requirements. Each utility must determine the available fault energy throughout the system based on the available fault current, time before the arc is extinguished, and the estimated distance to the employee. There is not a "one size fits all" answer.

Public Seminars

Proposed Changes in the OSHA 1910.269 Power Lineman Rules (Day 1) and Arc Flash Hazards and Arc Rated Clothing (Day 2) will be presented around the country this fall:
    September 16 and 17: Dallas, TX
    October 7 and 8: Newark, NJ
    November 12 and 13: Atlanta, GA

More information.

eLearning

Our new eLearning content allows you to learn at your own pace on your own time. Training is delivered in modules lasting approximately 10-15 minutes each followed by a small quiz. The progress is tracked, and each learner will receive a certificate upon completion of the course.

OSHA for Communication Workers is currently available online and courses in OSHA for Power Line Workers and The National Electrical Safety Code® (NESC®) are coming soon.

More information, including a free demo.