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April 10, 2012
Vote for the 2012 Product of the Year and Qualify for a Chance to Win $100!
Broken Breakers, Part 6
Electrical Troubleshooting Quiz
Replacing Cables, Part 9
NEC in the Facility
Safety

Product of the Year Competition


Vote for the 2012 Product of the Year and Qualify for a Chance to Win $100!

Your vote will help us identify the 2012 Platinum, Gold, and Silver Product of the Year award winners. Simply review the category winners, and then choose your favorite from the drop-down menu. Three lucky voters will be randomly selected to receive a $100 gift check.

The voting poll will remain open through 5 p.m. CST on May 25. Please, only one vote per EC&M subscriber. Any votes received from manufacturers, PR firms, or non-EC&Msubscribers will not be included in the final tally.

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Get a grip on accuracy.
The Fluke 62 Mini non-contact thermometer is the perfect introduction to infrared (IR) thermometers for the professional. With the best accuracy in its class, the Fluke 62 Mini offers quick and reliable surface temperature readings. Rugged enough for industrial environments with its protective rubber "boot, the 62 Mini also comes with a handy nylon holster.

Maintenance


Broken Breakers, Part 6

Breaker contacts should look fairly new even after years of service. Why? Because with properly aligned contacts, the only time severe damage should occur is when the breaker operates under load.

Before manually operating a breaker, methodically shut down all connected loads. Ideally, you will open a breaker only when there's no current flow across its contacts.

Of course, contact surfaces aren't perfectly smooth, and you don't get 100% contact between all surface points on the respective contacts. Some arcing will occur, and over time the surfaces will become pitted. You can typically recondition (by filing or sanding) the contact faces. Make sure you take photographs before and after filing.

But consult the breaker manual before reconditioning; there should be a specification on how thick the resultant contact must be. If you can't make that spec, replace the contacts.

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E-Mon D-Mon Smart Meters
E-Mon D-Mon Smart Meters provide advanced energy monitoring features for billing/allocation, power quality, load control, net metering and green building initiatives including dual-protocol communication for simultaneous operation with multiple BAS systems, billing packages, M&V reporting and/or E-Mon Energy AMR software. For information contact E-Mon, the Industry Leader in Submetering at (800) 334-3666 or visit www.emon.com/ecm212a.asp

Repair


Electrical Troubleshooting Quiz

A manually operated press motor has been blowing at least one of its bi-metal thermal overload strips nearly every day for the past month. The plant's power monitoring system doesn't have sensors at the load level, so a tech grabbed a DMM with high/low memory and connected it to record voltage on one phase. The DMM recorded a high spike of about 700VAC and a low of about 410VAC. Of course, these are point measurements, and the DMM shows nothing about their duration. Nor does it show when these occurred or how many spikes there were.

What other information do you need?

Visit EC&M's website to see the answer.

Replacing Cables, Part 9

If you have the time, look closely at cable pulling tension calculations for previous cable pulls. Do you see anything in there regarding the raceway entrance? It's usually assumed that the entrance provides no additional friction. Typically, the reality is the additional friction can be significant enough to result in cable damage or an outright failure of the pull.

You probably inspect for any sharp edges in the pull path and remove them. You may even place a thick rag in front of the entrance. Those precautions are good, but you could still have excess friction. Some tips on eliminating it include:

  • Use an approved raceway entry sleeve.
  • The person(s) feeding the cable into the entrance must straighten the cable so it has no "roll twist," feed it into the entrance at the minimum possible angle, and support it on its way in.
  • Liberally apply pulling lubricant as you're feeding the cable.

To read more on this story, visit EC&M's website.

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Baldor Electric Company
For decades, ABB variable speed drives and Baldor motors have set the standard for quality, reliability and energy savings. Now, industrial customers in the U.S. can buy these products and receive expert support from a single source. Call 479-646-4711 to locate the sales and support office nearest you. Click Here

Operation


NEC in the Facility

The concept of "working space" is commonly misunderstood, and consequently adequate working space is commonly not provided. OSHA provides tables with specific numbers, but it gets its numbers from the NEC. You will find this information in Table 110.26(A)(1) and in the various written requirements of 110.26(A) through 110.26(E).

If you look at Table 110.26(A)(1), it basically says you need a minimum of 3 ft of distance between exposed live parts on one side of the working space and grounded live parts on the other. It also says you need a minimum of 3 ft of distance between exposed live parts on both sides the working space, except when the voltage is greater than 150V. Then it's a minimum of 4 ft.

Amazingly, many facility planners extract from this that it would be nice to have pieces of electrical equipment about 3 ft apart, but not an inch more.

To read more on this story, visit EC&M's website.

Safety

If acid gets on your skin, you know immediately because of the burning sensation. This isn't true of bases, which can do their damage unnoticed until you see or smell the results. You'll also know if acid gets into your lungs or eyes, but the pain warning might not provide enough time to prevent serious injury. Be vigilant when working around acid.

Battery room ventilation is critical, but not always properly set up. If you smell "battery fumes," exit immediately. Don't enter again without adequate PPE and/or ventilation.

To read more on this story, visit EC&M's website.

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Thermal IR electrical inspections can include looking for loose connections, overheating fuses & breakers, insulation loss, and phase over/under loading, with the goal of finding a failure before it finds you. Testo thermal products provide a complete solution to capture, report, analyze and store your data. Click here.

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