Does NFPA 70E allow pressing the service button (pin) on the WattNode® in a live panel?
First, there is an alternative which should work in most cases: the WattNode has the Neuron® ID printed on the front label. Most LonWorks® network management tools allow the entry of the Neuron ID in place of pressing the service button.
If the WattNode is installed in a panelboard (breaker panel) or other electrical enclosure with exposed conductors, then there are some specific guidelines according to NFPA 70E (2009 Edition). The following is a partial list of relevant topics.
Because of the complexity of the NFPA standards, the frequent revisions, and local additions to the rules, you must consult local experts, rules, or authorities before deciding on a course of action. Continental Control Systems, LLC cannot guarantee that the following list is complete or accurate, and cannot be responsible for the final determination of the safety or allowability of any course of action.
- Section 110.8.(A).(1): Exposed energized conductors and circuits must be made safe (disconnected) before work is done within a safe distance boundary. This would rule out pressing the service button, because power would have to be removed first and the service button won’t work if power is off.
- Section 130.1.(A).(2): This allows work on energized circuits where a required task cannot be performed in a deenergized state due to the design of the equipment. This exception appears to allow pressing the service button, provided all other applicable rules are followed.
- Section 130.1.(B): Generally, work on an energized circuit requires a work permit. There are exceptions to this rule for testing, troubleshooting, etc. if the work is done by a qualified person.
- There are many additional rules on protective equipment, lockout, tagout, etc. that must also be followed, whether the circuit is energized or deenergized.
If the WattNode is installed in a separate electrical enclosure, the NFPA 70E standard is not completely clear as to the requirements. In particular, it’s not clear whether the green screw terminals should be considered exposed (capable of being inadvertently touched…parts that are not suitably guarded, isolated, or insulated). If the WattNode is properly installed, there should be no exposed wires, and the only possibly exposed items may be the screw heads on the green screw terminals. These screw heads are recessed and the openings are smaller than 5mm (the UL touch probe size), so it generally is not possible to touch them without using a conductive tool such as a screwdriver. However, NFPA 70E is unclear as to whether these would be considered exposed or not.
If a qualified person or relevant authorities decide that the WattNode in a separate enclosure does not have exposed parts, then it appears the 70E standard would allow pressing the WattNode service button (service pin) by an unqualified person without the use of safety equipment and without the need for permits, lockout, tagout, or any other precautions.