EC&M - Latest Comments

Re: Whats Wrong Here?

Chuck — Thu, 05 Nov 2009 17:54:38 -0000

What does the code say about the use of two-conductor zip cord to wire the three-prong receptacle on the base of the lighting fixture? Are you sure it's safe for me to plug in my old (not double-insulated) power drill for a little DIY work in this closet?

Re: The Ins and Outs of Optical Fiber Cable Installation

Dave — Thu, 05 Nov 2009 17:34:19 -0000

Ok. If I'm installing fiber optic cable more than 50 feet from outside into a building can non-fire rated cable be placed in fire rated inner duct without the use of rigid steel conduit?

Re: Wiring Methods for Industrial Machinery

randysimpson — Wed, 04 Nov 2009 14:05:19 -0000

In response to the artical above, we ship internationally and try to satisfy the requirements for NFPA 79 and the EN60204. Incoming facilities power to a electrical panel for distribution.

Single phase 230VAC facility power in Europe is one ungrounded Line and one Neutral, so you get 230VAC between Line and Neutral.

Question; what colors should be used as old EU black was Neutral and the new EU light blue is Neutral, and how light can light blue get! so as to not confuse with other blue wires such as 24VDC circuits. We can't be the only manufacture with this problem.

Do we just bite the bullet and wire all to EU standards for our EU customers or do we do somthing right down the middle, I know as long as the wire is identified with a label and documented in the schematic the color for Neutral can be black. What is everbody else doing these days?

Thanks,

Randy

• Black represents ungrounded line, load and control conductors at line

Re: The Fundamentals of a Successful Low-Voltage Lighting Design

timharger — Wed, 04 Nov 2009 10:55:39 -0000

did you get this figured out, if not you really need to run another wire of 12-2 to the area. also does your transformer have multiple volt taps if it does then you can try to up the voltage and even things out. the trick is balancing the load of lights out and making them all happy. your lights burned out because they were over volted and the other will burn out soon from being under volted. there is a lot of things to consider here. let me know

Re: Stumped by the Code?

Gary — Wed, 04 Nov 2009 10:24:25 -0000

what is the Pa. code for installiing 100 Amp underground service cable with reference to the type and depth of piping

Re: Line Reactors and VFDs

arun — Wed, 04 Nov 2009 08:39:33 -0000

In My VFD drive the drive is not start from local panel but only starts from Display controller. so what is the resaon.

Re: Whats Wrong Here?

AL GONZALES — Tue, 03 Nov 2009 20:25:15 -0000

YOU CANT HAVE AC , PHONE OR TV CABLE IN THE SAME SERVICE
CONDUIT AND BOX.

Re: The Top 40 Electrical Design Firms

facebook-1622972805 — Tue, 03 Nov 2009 07:21:22 -0000

The design build relationship puts more risk on the contractor but gives the client a more quality product. During the construction phase this can cancel out much of the "finger pointing".

Re: Sizing a circuit breaker.

donbrewer — Mon, 02 Nov 2009 20:49:05 -0000

I don't agree with all of your statements. The code states that 80% is the maximum you apply to that breaker load wise.Most breakers are in very harsh environments with many other current carrying breakers around them.The way you state this you could have a 199 amp load and use a 200 amp breaker with no problem. I don't think that is the case? To me the code is very clear 80% of its rate load.wheather it is continous or non continous load. This is what I have been tought buy code masters and engineers.

Re: Code Quiz

danroba — Mon, 02 Nov 2009 17:47:56 -0000

Type your reply...

Re: Code Quiz

danroba — Mon, 02 Nov 2009 17:47:09 -0000

It is a misleading question, There are no 50V or less recepticals. The question is just asking what is the minimum ampacity of kitchen recepticals? Put another way, What is the minimum ampacity of recepticals in the room you make cookies?

Re: Understanding The Basics of Wye Transformer Calculations

Tom Juliano — Mon, 02 Nov 2009 14:12:42 -0000

If I have 2400A at 208 into a 1000kva step up 480V transformer, can i get 1200A at 480V?

Re: Wiring Methods for Industrial Machinery

randysimpson — Mon, 02 Nov 2009 12:22:58 -0000

Hello,

We are a manufacture of table top Automation equipment as well as Custom Automation, our friends in the UK want us to identify the incoming Line Neutral and Earth as L N PE, not a problem, we can do this, the problem is some of our legacy equipment has universal voltage input 120/240 primary, and the secondary is always 120VAC with one side of the transformer grounded, this is technically our Neutral, our CE friends would like us to label the secondary with the L N identifiers, in the past we always let Auto Cad do automatic numbers based on the page and line reference, so the line and neutral conductors on the secondary could be any number. I would think that in addition to the line reference label a suffix N or L could be added so that the uninterrupted Neutral wire could be identified throughout. And the Line could be identified up to the distribution point. What is industry doing these days as CE is changing the way we identify wiring. Typically I would identify the Neutral by N and it would match the schematic.

Re: Code Q&A

Charlie Koubek — Mon, 02 Nov 2009 06:38:37 -0000

Paul,
In the illustration I see a ground rod supplied at the sub-panel. I have ran into a situation where I installed a 100 amp 4 wire main lug sub-panel to a garage.The inspector failed it for not having a ground rod located at this sub-panel. Correct me if I'm wrong but it is my undersatanding that all faults should reach the main principle. Adding a ground rod at this location could cause a difference of potential?

Re: Code Q&A

voltage — Mon, 02 Nov 2009 00:06:44 -0000

typically panels are not placed in storge areas. That is a safety issue

Re: Whats Wrong Here?

jcflyger — Sun, 01 Nov 2009 04:20:50 -0000

Yes that is Romex and Yes it is wrong SEOOW would of been exceptable. Would also like to coment on those feeder wires that are exposed to phisical damage. A quick fix of SCH 80 PVC would of been an adiquit solution for the code violations. Also the bell boxes should have an inuse cover for the recepticles...

Re: Code Quandaries

georgewolfe — Fri, 30 Oct 2009 12:20:16 -0000

What is the grounding requirements on a 24 volt DC fire alarm system. There is no 120 volt AC power nor is the conduit connected to any equipment or devices that may happen to be connected to any 120 Volt source.

Re: Whats Wrong Here?

curtis12 — Thu, 29 Oct 2009 18:59:54 -0000

different voltages..this is hillarious....

Re: The Case of the Misguided Plumber

Joe DiDonato — Thu, 29 Oct 2009 07:12:14 -0000

The circuit diagram should be enhanced by labeling the Hot, Neutral, and Ground Terminals on the GFCI Outlet to clearly show the error made with the connections from the Temporary Panel (GFCI to the Meter Pan).

Re: Verifying Ground-Fault Coordination for MV Power Cable Shielding

angelrivero — Wed, 28 Oct 2009 15:58:28 -0000

If we did not consider the telecommunication interferences, a solution so that shield of our cable not this exposed to ground faults external the own circuit, is to connect a single end of our MV cable grounding shield

Re: Unconventional Transformer Connections — Part 2

Keith Farnworth — Wed, 28 Oct 2009 00:56:32 -0000

Look at the above case 6 Tee to Tee connection.

Re: Unconventional Transformer Connections — Part 2

Keith Farnworth — Wed, 28 Oct 2009 00:51:18 -0000

It has been awhile since I have studied the connection I will tell you about. It uses two single phases that are 180 degrees out of phase. To get three phase out of the split single phase you can use a Scott connection. Actually I was searching for information on it to refresh my memory when I saw your post. If I find any more information on it I will post it. If you want to talk further about this please email me at umfarnwo@cc.umanitoba.ca and I will be happy to check my documents for more detailed information.

Keith Farnworth

Re: The Basics of Transformer Voltage Regulation

Asad Khan — Tue, 27 Oct 2009 00:21:10 -0000

The difference between no load voltage to full load valtage is called voltage regulation of transformer.

Voltage Regulation %=100 E n.l - E f.l /E n.l

Re: Don’t Be Left Short by Current Transformers

Bob — Mon, 26 Oct 2009 18:45:04 -0000

While the CT is in place and current is flowing through the conductor.If the wires (secondary metering shunt)going to the meter are not connected to the meter yet ,they should be shorted together.The meter socket provides this function simultaneously
when you remove the meter from the socket with the release bar.Leaving
these wires isolated will cause damage to the primary coil and open the
coil.
What do you think?

Re: Fast, Cheap, and Out of Control?

Larry Kingsbury — Sun, 25 Oct 2009 15:36:46 -0000

Thank you for the comprhensive article on PVC conduit. In our industry, the choice of materials often involves compromise. PVC is no exception. Phase to phase faults in 480-volt feeders can damage PVC conduit so severely that the conduit must be exposed and repaired. Faults can occur in plastic pipe at such low amperages that the feeder breaker does not sense the fault. The cost to repair this unusual damage certainly does not compare to the cost to repair corroded underground steel conduits should the need arise.

PVC also does not withstand high pulling forces when installed underground where ground water has caused voids. Several years ago I replaced 12 parallel runs of 500kcmil in PVC where the original cable was damaged during installation because of conduits that broke at 90 degree ells that were in sandy soil where the broken conduits damaged the cables. Eventually the faulted cables burned through all of the PVC conduits before the breaker eventually tripped. In hindsight, lightweigh concrete at the ell locations would have prevented this problem. Sand is at 100% compaction only if totally contained.