I believe that a change needs to be introduced to the verbiage in this section... I just don't know how to properly word it. The way the section is currently worded it is going to require disconnection of the grounded conductor to the supply wiring for the ballast. I can see a problem with this if the grounded conductor is part of a multi-wire branch circuit. If the switch is not attached to a "pig-tail" off of the grounded conductor of the circuit then the grounded conductor being disconnected from the circuit could introduce a hazardous condition. While section 404.2(b) does address this maybe language similar to 300.13(b) could be introduced into 410.73(g) to help alleviate this potential? Looking for suggestions or maybe I am reading too much into this.
410.73(g)
- Thread starter pete m.
- Start date
- Status
- Location
- Massachusetts
Re: 410.73(g)
Pete it is my understanding that the likely way manufactures will handle this is not the use of a switch at all.
I have heard we can expect to see them use a nylon male and female plug.
The pig tailing of the neutral will be done by us in the field to conductors that supply the receptacle, that receptacle in turn will feed the ballast.
But plug and receptacle or switch it does not matter the grounded connector and for that mater the ungrounded conductor will both end up pigtailed.
I imagine multiwire branch circuits are exactly the reason they are requiring both conductors to be disconnected by the disconnecting means.
Pete it is my understanding that the likely way manufactures will handle this is not the use of a switch at all.
I have heard we can expect to see them use a nylon male and female plug.
The pig tailing of the neutral will be done by us in the field to conductors that supply the receptacle, that receptacle in turn will feed the ballast.
But plug and receptacle or switch it does not matter the grounded connector and for that mater the ungrounded conductor will both end up pigtailed.
I imagine multiwire branch circuits are exactly the reason they are requiring both conductors to be disconnected by the disconnecting means.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: 410.73(g)
What I have heard is each light will have a two pole switch between the ballast and the circuit wiring then a connector that is on the ballast like some of the electronic types now have. But it won't be required until 2008. So we have a long wait.
What I have heard is each light will have a two pole switch between the ballast and the circuit wiring then a connector that is on the ballast like some of the electronic types now have. But it won't be required until 2008. So we have a long wait.
Re: 410.73(g)
However, a read of the rules is that IF there are enough branch circuits installed that disconnection at the supply panelboard will not leave the area in total darkness, then that is an acceptable method.
However, the circuits breakers would need to be handle tied in the case of shared neutrals for this application.
Other alternative methods:
A disconnect for each row of lights if there are enough rows for this to be practical.
Fully insulated quick connects instead of 2-prong plugs. The Molex type nylon plugs are not rated for load breaking or making.
An electrical inspector told us at a Code meeting that the disconnect is for both ballast change and LIGHT BULB CHANGES. Changing the bulbs while the ballast is alive tends to damage both the ballast and the bulbs.
Also, I have also had to take down 400 watt metal halide and high pressure sodium fixtures to change the bulb. It sometimes takes 3 people to wrestle the bulb out of the socket which is more than allowed in a high reach.
However, a read of the rules is that IF there are enough branch circuits installed that disconnection at the supply panelboard will not leave the area in total darkness, then that is an acceptable method.
However, the circuits breakers would need to be handle tied in the case of shared neutrals for this application.
Other alternative methods:
A disconnect for each row of lights if there are enough rows for this to be practical.
Fully insulated quick connects instead of 2-prong plugs. The Molex type nylon plugs are not rated for load breaking or making.
An electrical inspector told us at a Code meeting that the disconnect is for both ballast change and LIGHT BULB CHANGES. Changing the bulbs while the ballast is alive tends to damage both the ballast and the bulbs.
Also, I have also had to take down 400 watt metal halide and high pressure sodium fixtures to change the bulb. It sometimes takes 3 people to wrestle the bulb out of the socket which is more than allowed in a high reach.
- Status