- Location
- Illinois
- Occupation
- retired electrician
Do speakers for a paging system fall under the rule 502.150(B)(2) or (B)(3)?
speakers in Class II, Div 2 Group G
- Thread starter don_resqcapt19
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I would say "yes".
To me the term "communication systems" would include the speakers.
I'm sure you are aware some speaker systems have a 70 volt
supply which can produce a decent arc.
http://www.federalsignal-indust.com/default.asp?pageID=4&lookup=880
(with YOU asking that question I think I am overlooking some questionable "verbage" but I can't find it)
To me the term "communication systems" would include the speakers.
I'm sure you are aware some speaker systems have a 70 volt
supply which can produce a decent arc.
http://www.federalsignal-indust.com/default.asp?pageID=4&lookup=880
(with YOU asking that question I think I am overlooking some questionable "verbage" but I can't find it)
Last edited:
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I would agree with Augie on this one and I would also probably consider the speakers were part of an audio signaling system within the Scope of Article 640.
With the back references to 501.120 (B)(2) and/or (B)(3) my only serious concern would be the T-Class; otherwise a simple dusttight enclosure would be suitable as identified for Class II. (Types 3, 3S, 3SX, 3X, 5, 12, 12K, 13)
Last, but certainly not least, I've noticed a recent trend toward (what I consider) over-classifying Group G locations. I don't want to imply Group G is trivial, but it really takes a LOT of material in suspension to create a serious explosion. A healthy fire is possible though, which is why I'd take a careful look at the T-Class or consider simply locating the speaker outside the classified location, if possible.
With the back references to 501.120 (B)(2) and/or (B)(3) my only serious concern would be the T-Class; otherwise a simple dusttight enclosure would be suitable as identified for Class II. (Types 3, 3S, 3SX, 3X, 5, 12, 12K, 13)
Last, but certainly not least, I've noticed a recent trend toward (what I consider) over-classifying Group G locations. I don't want to imply Group G is trivial, but it really takes a LOT of material in suspension to create a serious explosion. A healthy fire is possible though, which is why I'd take a careful look at the T-Class or consider simply locating the speaker outside the classified location, if possible.
- Location
- Illinois
- Occupation
- retired electrician
What if the speaker is just an 8 ohm extension speaker for a radio or stereo? The workers need to listen to something while they work:grin:
The area is over classified in my opinion, but they want to pay me to upgrade the electrical system to match the classification. Most of the work would be changing the light fixtures and receptacles.
The area is over classified in my opinion, but they want to pay me to upgrade the electrical system to match the classification. Most of the work would be changing the light fixtures and receptacles.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
As I said my, greatest concern would be their temperature; speakers can get pretty hot. (They're terribly inefficient)
If they were located where they might collect a little Group G dust occasionally, I'd get something like Augie pointed at and not look back. If housekeeping was poor and the dust layer could get thick I?d even consider looking for a Division 1 unit. Otherwise, if I knew the T-Class was acceptable I?d still opt for dusttight. I just don?t see ignoring the Area Classification ? even if I personally thought it was excessive (and, like Augie, I suspect your evaluation of the situation is probably correct)
If they were located where they might collect a little Group G dust occasionally, I'd get something like Augie pointed at and not look back. If housekeeping was poor and the dust layer could get thick I?d even consider looking for a Division 1 unit. Otherwise, if I knew the T-Class was acceptable I?d still opt for dusttight. I just don?t see ignoring the Area Classification ? even if I personally thought it was excessive (and, like Augie, I suspect your evaluation of the situation is probably correct)
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