Electronics Forum / Electrical Engineering / January 2006

I have two currently unused 3-Phase transformers, one 30KVA and the
other 45 KVA.
Both are connected in reverse, converting 208 up to 460
I need 65 KVA of 3-Phase 460 power to run a new motor (50 HP)

I'm beginning some projects, entirely for my own education and
amusement.
Among these 'Saturday' projects, I'll be creating a DC or AC motor of
some design, from scratch, and have a few questions:

My sister has a heat pump.  She has bought a thermostat that says it
works in 99% of homes.
Many years back I bought a programmable thermostat for my home that
has gas heat.  I remember at the time I bought it there were

I wish to set up a website and am unsure of the best way to go about it.
My intention is to produce the site in Microsoft Word and then upload it to
a central server.
My understanding is, if I do this I must download some software I use to

I have an air cylinder that I want to use to move a part back and forth
at a variable rate.
Is there any type of rheostat relay controller that will toggle the air
pressure from each endpoint of the cylinder.  This needs to be very

Take advantage of a great deal

Hi, I'm building a pc/104 PC as a side project for fun.  I purchased a
pc/104 board as well as the he-104 12v vehicle power supply
(http://engineering.tri-m.com/products/power/he104.htm).  The system
will enventually reside in a car with 12VDC power but during

I am looking for an autoranging front-end circuit to convert a
universal AC input ( 90-265VAC ) to an unregulated DC voltage ( in the
range of 220-400VDC ) to power some DC supplies at 90 Watts.
It seems that such a front-end should operate as a doubler/rectifier in

See there is a slight issue in the world. Look as I might I cannot find
anything similar to PSCAD (www.pscad.com) for the *Nix platform. This is a
crime for all intents and purposes. I've seen a few other vendors but most
all are Windows only and this isn't workable. For a startup ...

A few years ago I remember there being something in the code book about the
minimum size of wire (I believe it used to say that you could only phase
tape wires larger than #8) that was allowed to be phase teped to identify
the circuit color that it was, but I haven't seen any ...

Anyone know if a standard GE or Dayton motor rated at 220/240 volts can be
easily wired to run on 110/120. Most motors seem to have the option for
both, however if it doesn't state it on the nameplate can it still be done
and how? Thanks - Ken

I have a question about grounding a 120/240 1ph 3w system.  I am trying
to determine if it is a violation of the 1999 NEC if their is a ground
to neutral connection on the load and service side, and the two geound
to neutral connections are connected.  Thanks.

In my country Ghana, most houses have a 3 phase 4 wire system at 220-240
volts. Some if not most electricians use 16mm2 THHN wire to connect from the
service point, through the watt hour meter and to the load center. This is
for 200 amp service. I thought a 200 amp service would ...

Is it possible to figure out the rpm of a motor through its voltage and
wattage and such.
I have a pedestal fan motor.......its specs are
230-240V a.c., 50Hz, 50 Watt

I have completed a new offset bend calculator in JavaScript and placed
it at my site http://www.electrician.com under calculators.  There is
an extensive article describing how this calculator is programmed.
This calculator does not use the Benfield Tables that are very