I would say no. There is no reference to it in the code book. It is good practice to install a cover that says 347 though, it gives a heads up to whoever is working on it.
They make stainless steel flush switch covers that have 347 stamped on them and I think that they make them for FS boxes as well. I don't think that they make them for regular surface mounted boxes though.
#102769 - 11/02/0610:00 PMRe: 347 v marking on cover plate.
Marsbar, your reference is to the integral disconnecting means that is now required in each flourescent fixture that is supplied by voltages exceeding 150V to ground. That rule is not talking about the light switch that Cinner is refering to.
Whoever told you that is wise because safety is key but it is not required and there is no code rule.
#102772 - 11/07/0604:14 PMRe: 347 v marking on cover plate.
The new rule only applies to new fluorescent fixtures that are supplied by voltages exceeding 150 Volts to ground. I never saw one yet because I have only worked on older fixtures and never had to install a new one this year.
Look at 2006 CEC -
Rule 30-308 (4)Each fluorescent luminaire installed on branch circuits with voltages exceeding 150 volts-to-ground shall be: (a) provided with a disconnecting means integral with the luminaire that simulataneously opens all circuit conductors between the branch circuit conductors and the conductors supplying the ballast(s); and (b) marked in a conspicuous, legible, and permenant manner adjacent to the disconnecting means, identifying the specific purpose.
The description of the integral disconnect I guess could be anything, switch, plug, just as long as it does what the rule says.
Wish I could give you a picture of one but I never saw one.
I would say that they would not be able to sell 347V fixtures in Canada without one anymore because it has to meet the CSA standard. Since the CSA wrote the code book you would think that they updated their CSA Standard on the fixtures.
Hope this helps.
#102774 - 11/08/0611:15 AMRe: 347 v marking on cover plate.
CEC 2006 12-3002 Outlet box covers "cover plates installed on flush mounted and surface mounted outlet boxes shall be a type for which each is designed." A 347v switch is longer than a standard switch and would require a 347 box and cover plate. our ESA rep. mentioned that it may be added to the code as the number of accidents that occur. You are correct RobbieD.