We've just encountered the requirement for this in the 2012 International Building Code Section 3007.6.2. This requires the entire shaft to be lit to min 1 foot-candle measured on top of the car when firefighter's emergency operation is active. How is anyone achieving this these days...
Anyone have any experience with Baldor Generators? The local sales rep made a pitch for them a couple of years ago and we've been asked by the electrical contractor on a project if we would accept one. I know they've made fine motors for decades but haven't seen their generators installed in...
Adding a generator to serve the entire load of a building. The intent is to intercept the underground service (multiple sets of 3 hots & grounded neutral in PVC ductbank) between the utility padmount transformer and the switchboard inside the building and install an ATS oudoors. This ATS will...
Any opinions on allowing the use of Metal Clad - All Purpose cable in an office building in US? We generally allow regular MC cable, with the green insulated ground wire normally terminated with wire nuts. Electrical contractor wants to use MCAP, which has a #10 aluminum bond wire which is...
Found the following quote on a cycling forum and wondered what you guys thought about it. Not sure if vehicles means cars or bicycles. Not even sure if he really means transmission poles or just your average medium voltage distribution pole line.
"I'm an electrical engineer in Australia, and...
For a typical 480V, 3 Ph, generator, say under 2 MW, is the output circuit breaker(s) really protecting the generator winding? Obviously the NEC says you need protection for the feeder conductors but not sure if the breaker does anything for the generator. I've been under the impresssion that...
Typical high bay HID fixtures are available with either the hook or the loop on the fixture. Is there a standard that states which should go on the fixture and which should go on the structure? Do contractors or maintenance people prefer one over the other?
I am going to be designing the power distribution system for a movie studio (sound stage). We have been told that in addition to the normal 120Y/208V AC supplied for production lighting, several thousand amps at 120V DC is required for additional lighting of some type.
Does anyone know just...
I'm working on a 5 story hotel project which will use battery packs for egress lighting. The city reviewer has come back and said that we need to add a generator to supply the elevators so they can be used as an "accessable means of egress". They are citing IBC (International Building Code)...
Is there anything in the NEC that prohibits mounting a panelboard behind a door? This is the only wall space left in a small room. With the door closed there is plenty of NEC required clearance in front of the panel. The door obviously prevents anything from being stored there. Does anybody...
I'm working on a project that will have over 70 wind turbines mounted on a building. Each turbine will have a generator with a max output of 10kW, (120VDC @ 80A). I'm looking for some inverters that could be used to produce 480VAC, 3 phase output. These would synchronize with the grid and...
Anyone know what sort of demand factor could be applied to the AC input load of multiple battery chargers for golf carts? This involves over 50 carts. I'm assuming the chargers are integral with the carts but not being a golfer I don't know if this is true. Not that it would matter.
What is special about light fixtures recessed in a ceiling used for return air in the City of Chicago. I notice many fixture cut sheets with a "Chicago Plenum" option. What do they know in Chicago that everybody in the rest of the US does not? Or is this just a reaction to Mrs. O'Leary's cow...
Working on a new, low-rise, office building project. Since the building was completed the utility has lost a phase several times, probably due to construction in the local area. No problems with equipment, only partial lights out. Client wants to know why we didn't specify phase loss...
The NEC section 605.6 & 605.7 now requires multiwire branch circuits supplying the partition to be provided with a means to simultaneously disconnectall ungrounded conductors. This seems simple enough with 3 circuit furniture, just use a 3 pole breaker. But many manufacturers offer 4 circuit...
I want to put a 225 kVA dry-type transformer outside, which seems pretty ordinary. However, this transformer will only be energized when an outdoor emergency generator is running. I am concerned about moisture getting in the insulation during the long periods of non-use. Has anyone...
Does anyone have a preference in combination motor starters for using a thermal-magnetic circuit breaker (CB) versus using magnetic only motor circuit protectors (MCP)? Or does anyone like fusible switches with dual-element fuses? This is in regular 208 or 480 volt, 3 phase projects in the...
I recently designed a building addition that required an 800A molded case circuit breaker to be added to an existing (less than 5 year old) 3000A GE switchboard. There appeared to be plenty of space in the board, a whole section as a matter of fact. When the electrical contractor went to...
I'm working on a hospital project where the facility person is insisting on yellow plates on all the emergency outlets. Does anyone have a source for these? I'd hate to just have my electrician spray paint some metal plates.
Is there any code that requires that laboratory exhaust systems be shut down by the building fire alarm system in the event of fire. These would include lab hood exhaust, biosafety cabinet exhaust and general lab exhaust. Seems to me that you would want these fans to be on during a fire to...
