Is anyone looking at either of these cloud apps?
My firm currently uses Masterspec and we have been told it is being phased out this year and the replacement is a cloud based service called Specpoint. We got a demo account of Specpoint from our sales rep, but frankly the pricing we are being...
It is well known that an un-bonded ferrous metal sleeve or conduit surrounding a single conductor adds substantially to the inductance of the conductor. Does anyone know of any actual measurements of this effect, and the effect of bonding the sleeve to the conductor?
IEEE 142 (Green Book)...
When an iron core reactor or transformer is driven into saturation, is there a finite amount of time required for saturation to occur?
Textbooks always discuss in terms of B-H curve, but time is not generally a parameter.
Alan
The engineer's first problem in any design situation is to discover...
Hello! I've been away from eng-tips for a while, but thought this would be a good question for this group.
The 2017 NEC, paragraph 240.67 requires, starting in year 2020, that low-voltage fuse protection 1200A and larger have a means to reduce potential arc energy, similar to the present...
Way back in 2009, I posted thread238-234338 here about failure of surge arresters on a 4.8 kV ungrounded delta system owned by my client. I received some excellent feedback at the time and thought I would post an update.
The arreters were replaced in 2009 with new IEEE C62.11 station class...
Using SKM Powertools for arc flash studies and labeling, I've been wondering if there is a better way to handle LV transformers where there are multiple buses in a single enclosure. I usually print separate labels for each bus, which was the suggestion of SKM's technical support. It bothers me...
Well it's been a long time since I've posted here. Maybe some of you guys and gals can give me some advice.
I'm involved in a small wind turbine project (two 2 MW units). We are connecting to an existing 12.47 kV campus system (the utility substation transf serving the campus is Dyn). The...
I'm looking for a TCC for an ABB Type PS, Issue RT-706 MCCB.
There was another inquiry here: thread238-233687, but no conclusion was reached. Just wondering if anyone has any ideas on how to find this. ABB support seems clueless, but I probably just haven't found the right gray hair.
Alan...
I have two Cat 3512BDITA 1.5MW DEGs with EMCP II and ADEM controls. We need to synchronize the outputs to a utility source (without actually paralleling) so that static switches supplied from the generator and the utility source can operate in fast transfer mode whenever possible.
Does anyone...
I'm wondering if the traffic level here is any indication of the popularity of Revit in the engineering community. Architects I know seem to like it. It's all some of them talk about. M/E/P engineers not so much in my experience so far.
Alan
“The engineer's first problem in any design situation...
Does anyone know of a source for CAD files of the RUS overhead distribution standard details (Bulletin 1728F-804)?
Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.
Siemens recently announced availability of a 3 MW direct-drive turbine. Their web site is severely lacking in any technical details however. Makes me wonder if it's real.
GE's acquisition of ScanWind (Norway) last year should put them in the direct-drive business, but I don't see anything about...
A recent test on a client's low-voltage system in a data center indicated a neutral-ground connection somewhere downstream of the main disconnect. We have inspected everywhere we can think to look, but no signs of the connection. We could use current injection to try and locate the extraneous...
Interesting idea -
http://finance.yahoo.com/news/Superconductor-Electricity-bw-1358093940.html?x=0&.v=1
http://www.tresamigasllc.com/
Available conventional transmission capacity to connect this project may be a big piece of the puzzle.
Alan
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"It’s always fun to do the impossible." - Walt...
I have a outdoor utility-owned pad-mounted transformer, 480Y/277 4-wire secondary, serving a switchboard in a building via cable in underground conduit. The transformer is located very close to the building.
The utility requires a ground ring surrounding the transformer, which is bonded to the...
It may not be entirely PV, but seems headed in that direction.
http://www.bloomberg.com/apps/news?pid=20601130&sid=aN2RJ9ob3OoY&refer=environment
Alan
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"It’s always fun to do the impossible." - Walt Disney
My firm has been asked to provide a price for designing a small but complex facility. The client wants an alternate price for doing the complete A/E design in Revit. We have all architectual/engineering disciplines in house, but so far only our architects and structural engineers are experienced...
We experienced failure of the arresters I mentioned in thread238-213060. The utility feeding this switchgear is 4800V ungrounded with about 21kA sym available. The circuits are from a common substation bus, ungrounded, and do not have recloser operation. I selected an intermediate class polymer...
In another thread we discussed transmitting RF over power lines. Here's an article on transmitting power with RF. Tesla would be proud.
http://www.lightninglab.org/papers/WirelessPower/index.html
