BSL3 lab Junction boxes

Status
Not open for further replies.
mshields

mshields

Senior Member
Location
Boston, MA
The commissioning agent on a BSL3 lab we designed and which is under construction is recommending that we use "wet application" junction boxes for all wiring devices. Perhaps in place of all J-Boxes - I'm not clear on that yet. I confess to never having heard of these. He indicated that these were a best practice for the application. These have threaded conduit inputs so we'd have to convert to IMC and he mentioned something about caulking ahead of these boxes which I'm assuming implies a seal similar to explosion proof type. My confession here, is ignorance as to whether or not this really is a better way to go than ordinary J-Boxes. How critical is it (it would be a change order) and do we in fact need to apply a seal ahead of the J-box.

Thanks,

Mike
 
P

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
mshields said:
The commissioning agent on a BSL3 lab we designed and which is under construction is recommending that we use "wet application" junction boxes for all wiring devices. Perhaps in place of all J-Boxes - I'm not clear on that yet. I confess to never having heard of these. He indicated that these were a best practice for the application. These have threaded conduit inputs so we'd have to convert to IMC and he mentioned something about caulking ahead of these boxes which I'm assuming implies a seal similar to explosion proof type. My confession here, is ignorance as to whether or not this really is a better way to go than ordinary J-Boxes. How critical is it (it would be a change order) and do we in fact need to apply a seal ahead of the J-box.

Thanks,

Mike
Click to expand...

I would read the spec and see what they asked for. If they did not ask for them, i would be preparing a cost adder. That usually shuts them up pretty fast.
 
steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
I'm thinking it will be a lot easier (and cheaper) to give them what they are asking for now, than to try and retrofit a solution if the room fails commissioning.

Not to mention the possible impact on the schedule for the owner if they are counting on being up an running at some particular date.
 
M

MEP_PM

Member
In addition to sealing inside the conduits as prevously mentioned. Also check for sealing details around boxes and conduits that passing through the walls (EC or drywaller scope?). As well as checking your fixture shop drawings for opening/knockouts that could allow air to pass between spaces. We had 2x4 fixtures that had prepunched screw holes that had to be sealed.
 
M

MEP_PM

Member
steve66 said:
I'm thinking it will be a lot easier (and cheaper) to give them what they are asking for now, than to try and retrofit a solution if the room fails commissioning.

Not to mention the possible impact on the schedule for the owner if they are counting on being up an running at some particular date.
Click to expand...

Agreed, you don't want 8-10 people standing around watching a room pressure test fail. Then have someone hold a lighter up to the switch and receptible plates only to see the flame nearly get blown out by the air being sucked into the room. :-(
 
Status
Not open for further replies.
Top