HOME | Best Web Host | Question of the Week | Archived Questions | More Archived NEC Questions | Still More Archived Questions | Still More Archived Questions-2 | Still More Archived Questions-3 | Articles | Electrical Deficiencies | More Electrical Deficiencies | Electricians Tools | Online computers | Cybercorner | Electrician's License | Electronics Tutorials | Electricians' worksaving ideas | Electronic Theorems | Satellite Dish | Digital Cameras and Equipment | HTML Color Chart | Electronic Acronyms | Electronic Definitions | Electrician's Soldering Tutorial | Photovoltaic Power | Wind Power | Fire Alarm Basics | More Fire Alarm Info | Working with MC and EMT | Electricians' Color Code | Wiring Commercial Garages | Managing Your Emergency Lights | Lighting Design | Industrial Wiring | Wiring Ethernet | Residential Wiring | Low Voltage Wiring | PLC Overview | Electrical Troubleshooting Techniques | Using Loop Impedance Meter | Ten Common Grounding Errors |NEC and Low-Voltage Wiring | Raceway Protection and NEC | Working with Metal Raceway | Inductance and Characteristic Impedance | Understanding Capacitance | History of the Ethernet | Twisting Data Conductors | NEC Article 800, Communications Circuits | NEC Article 810, Radio and Television Equipment | NEC Article 820, Community Antenna and Radio Distribution Equipment | NEC Article 830, Network-Powered Broadband | Troubleshooting Submersible Well Pumps | Wiring Healthcare Facilities | First Edition National Electrical Code 1897 | Books for Electricians | Links



It is a great pleasure to announce the publication by McGraw-Hill of my new NEC 2011 guidebook. Reader feedback will be appreciated --



My second McGraw-Hill book for electricians, Troubleshooting and Repairing Commercial Electrical Equipment, now available from Amazon --






Now I've written a third McGraw-Hill book, out soon. The title is The Electricians's Trade Demystified. It is available for pre-order from Amazon. Click below --








MikeHolt.com

Wilderness Light Photography: Custom, commercial, landscape, nature, weddings, portraits, stock images by Judith Howcroft -- wildernesslightstockphotos.com


Order Electricians' Books Online --

Electricians' Books


Order Satellite Dish Installation Tools Online --

Summit Source

Order Klein Electricians' Tools Online --

Klein Tools


Order Greenlee Electricians' Tools Online --


Order Ridgid Electricians' Tools Online --


Order Milwaukee Electricians' Tools Online --

Milwaukee 49-22-4085 17 Piece Deluxe Electricians' Hole Saw Kit

Milwaukee 49-22-4085 17 Piece Deluxe Electricians' Hole Saw Kit

Milwaukee 49-22-4085 17 Piece Deluxe Electricians' Hole Saw Kit Since its founding in 1924, Milwaukee has focused on a single vision: to produce the best heavy-duty electric power tools and accessories available to professional user. Today, the Milwaukee name stands for the highest quality, durable and reliable professional tools money can buy. This deluxe 17 piece Electricians' Hole Saw Kit has the ultimate range of diameters available. The 12 diameters include: 5/8 inch, 3/4 inch, 7/8 inch, 1 inch, 1-1/8 inch, 1-1/4 inch, 1-3/8 inch, 1-1/2 inch, 1-3/4 inch, 2 inch, 2-1/2 inch, and 3 inch. The kit also includes arbor 49-56-7000 for hole saws up to 1-3/16 inch and arbor 49-56-7140 for hole saws 1-1/4 inch and larger. Additionally the kit has three pilot bits 49-56-8000 and an impact resistant plastic carrying case. The case is also sold separately as 48-55-0784. The hole saws in this kit are of the 6 teeth per inch design. Milwaukee 49-22-4085 17 Piece Deluxe Electricians' Hole Saw Kit Features: • Deluxe assortment of 12 hole saws, two arbors, and three pilot bits • Hole Saws: 5/8 in., 3/4 in., 7/8 in., 1 in., 1-1/8 in., 1-1/4 in., 1-3/8 in., 1-1/2 in., 1-3/4 in., 2 in., 2-1/2 in., 3 in.




Order Dewalt Tools Online --



This article originally appeared in Electrical Contracting Products Magazine

Working in An Industrial Setting


By David Herres


A variety of voltages, VDV technologies, transformers and distribution channels highlight most industrial operations.

An industrial facility is typically served by large three-phase services which supply a variety of voltages. Even a relatively small set of buildings may have several customer-owned transformers and numerous distribution panels sprouting thousands of branch circuits and countless power outlets.

Since significant office space is usually involved, electrical contractors will often see customer-owned PBX (private branch exchange) telephone service emanating from a central office with a computer-controlled switch. In addition, with Internet service and an in-house Intranet, there will be a telecom room with Ethernet, wireless or optical fiber network. You don't have to look far to find a supervisory fire alarm with telephone, sprinkler and fire door interface and elevator capture. And speaking of elevators, extended downtime in this area can mean massive curtailment in productivity.

To keep all this running efficiently, an electrical maintenance department is required, complete with knowledge and expertise, tools, inventory and operating capital. When existing resources are not able to deal with an emergency situation or scheduled new construction, it is necessary to call in outside help and in these situations a pre-existing working relationship with local contractors is essential.

As an example, consider the elevator. If it goes out of service, in-house electricians are called immediately. If people are stuck between floors, the electrical personnel must certainly know how to lock out the main disconnect, get the door open and lower a stepladder so that people can get out quickly and safely. The next task is to diagnose the cause of failure. Usually, it is a door interlock adjustment, circuit board fuse or similar component failure. Then the controller can be reset and the elevator is back in service.

At times the problem eludes in-house staff and a professional elevator servicing firm has to be called in. It is vital to maintain a good working relationship with these and other outside contractors so that they will come quickly.

What to know

An area of great concern in elevator maintenance is licensing. Regulatory authority resides with State and/or Municipality and varies widely throughout the country. It is important for facility electricians to know where to draw the line in terms of permitted elevator maintenance.

In all cases, safety for company personnel and onsite visitors is the prime consideration. The National Fire Protection Association (NFPA) puts out the National Electrical Code (NEC) and the Life Safety Code (LSC), which are currently revised every three years. These two volumes, along with a number of other standards, are offered by the NFPA so that states or municipalities may adopt them into law with changes or amendments if desired.

These mandates must be followed closely by designers and installers. Good industrial maintenance electricians know these codes and keep informed of new developments.

A conscientious and knowledgeable electrical department with good outside contractors will insure the facility is a safe workplace from an electrical standpoint. Then the issues of efficiency, economy and productivity can be addressed.

It is essential to always be evaluating the overall electrical infrastructure for adequacy. With the expansion in use of sensitive electronic equipment, for example, power quality and grounding need to be watched closely. These issues are also important where large motors are in use.

Good grounding requires an adequate set of ground electrodes but it goes way beyond that. Proper non-corroded terminations and reliable bonding of cable tray segments and similar equipment are essential elements. Redundancy is helpful in insuring reliable bonding but the wrong sort of redundancy can be a fatal error. Bonding neutral and equipment grounds in more than one location can give rise to objectionable circulating currents, which are dangerous and wasteful.

If motors and other utilization equipment are removed for servicing, it is important that the equipment grounding path be reliably reconnected so that overcurrent devices will clear a fault and prevent metal casings from becoming energized.

Dangers to know


Other major concerns in an industrial setting are hazardous (classified) areas. NEC recognizes three discrete types of hazardous areas, each with different wiring requirements.

Class I locations have fire or explosion hazards due to the presence of flammable gases, vapors or liquids.

Class II locations may have fire or explosion hazards due to combustible dust.

Class III locations may have fire or explosion hazards due to ignitable fibers and flyings, as in a textile mill.

Each of these classes has two divisions. Division 1 is generally more hazardous than Division 2 because the exposure is more immediate. For example, in Class I Division 1 locations, flammable gases or liquids can exist under normal operating conditions. In Division 2, they are normally in closed containers or systems from which they may escape in case of accidental rupture or breakdown. In all classes, Division 1 carries with it more stringent wiring requirements than Division 2.

It is important that electrical maintenance workers and contractors be aware that because of changes in building usage new hazardous areas may be created and that class and division boundaries may shift so that non-compliant wiring will have to be upgraded.

A key responsibility of industrial facility electricians is in the area of emergency lighting. Most such occupancies use individual unit equipment, self-contained boxes with sealed batteries and chargers that are connected to the AC lighting branch circuits ahead of any switches. AC failure triggers a relay that actuates on-board and remote DC lights and also drives the DC portion of nearby exit lights.

The LSC mandates placement and light levels of these units and NEC sets standards for wiring them. NEC requires that emergency lights be regularly inspected and written records be kept. The LSC further requires that testing be performed for 15-seconds once every 30 days and 1 1/2 hours every year.

Maintenance electricians are expected to correct any deficiencies found during inspection, replacing bulbs, batteries and circuit boards as needed. A medium-sized industrial facility easily can have several hundred of these unit emergency lights, so just the cost of battery replacement can be significant. For this reason, it is important to keep good records. A unit that needs new batteries every month, for example, should have its charger replaced.

Industrial sites are characterized by size and complexity. Electrical loads are large, numerous and diverse. In order to maintain a safe and efficient workplace, written documentation including as-built drawings should be on file with amendments added whenever changes occur. These files can be used to generate a spare parts list so that you can decide on inventory.

Lighting awareness


Fluorescent bulb management is important. The old T-12s should be changed over to the thinner, more energy efficient T-8s. This changeover, which may be partly subsidized by utility incentives and tax credits, involves changing ballasts and bulbs, but fixtures, wiring and sockets remain unchanged. It is also a good idea to put in the new NEC mandated internal disconnects so future ballast changes do not have to be performed live.

Many organizations change bulbs only when they begin to flicker or go out completely. This is a costly error. As fluorescent bulbs age, they produce less light and more heat, and they draw more current. This causes premature ballast failure. Early pre-emptive bulb replacement saves on the energy bill and also precludes costly ballast replacement. Fluorescent bulbs that have begun to darken at the ends have seen better days. Large industrial facilities should change fluorescent bulbs according to a fixed schedule.

Undoubtedly down the road all lighting will be LED based.

Emerging technologies


Electrical work has become far more complex in this cyberworld that we now inhabit, and this is especially true in the industrial setting. Virtually all large manufacturing environments now contain Programmable Logic Controllers (PLCs). These incredible machines were first developed for General Motors in the 1960s to facilitate the automation changeover that took place annually as new models went into production. Previously, it had been necessary to rewire thousands of relays, mechanical timers and the like.

In place of hardware, this equipment consists of software instructions placed within a central processing unit. We program a PLC by plugging into it a conventional laptop and creating simple ladder schematics. Instructions are sent to complex machinery so that timing of powerful operations takes place on a microsecond level. Thus Ford's assembly line has achieved a new flexibility and versatility thanks to GM.

This new technology is now everywhere in the industrial world and maintenance electricians are key players in making it work. The individual technician has the option of accessing online knowledge bases such as PLCtutor.com in order to become a player in this arena.

Industrial electrical work is a blend of space age electronics and traditional hardwire technology. As never before, it is an open-ended situation for those who have an interest in forming the future.
--END--


Books for electricians --

Here is a selection of the most significant electricians' books available online today, at the best prices around. Clicking on any logo provides access to reviews and ratings by electricians. A good place to start is with the 2008 NEC Handbook, which contains the complete text of the current code plus extensive commentary, diagrams and illustrations. Other books of interest for the electrician are available as well.

Low Voltage, Telecom, Fire Alarm Books --


This site is created and conducted By David Herres, NH Master Electrician License #11335M

E-mail: electriciansparadise@hughes.net


HOME | Best Web Host | Question of the Week | Archived Questions | More Archived NEC Questions | Still More Archived Questions | Still More Archived Questions-2 | Still More Archived Questions-3 | Articles | Electrical Deficiencies | More Electrical Deficiencies | Electricians Tools | Online computers | Cybercorner | Electrician's License | Electronics Tutorials | Electricians' worksaving ideas | Electronic Theorems | Satellite Dish | Digital Cameras and Equipment | HTML Color Chart | Electronic Acronyms | Electronic Definitions | Electrician's Soldering Tutorial | Photovoltaic Power | Wind Power | Fire Alarm Basics | More Fire Alarm Info | Working with MC and EMT | Electricians' Color Code | Wiring Commercial Garages | Managing Your Emergency Lights | Lighting Design | Industrial Wiring | Wiring Ethernet | Residential Wiring | Low Voltage Wiring | PLC Overview | Electrical Troubleshooting Techniques | Using Loop Impedance Meter | Ten Common Grounding Errors |NEC and Low-Voltage Wiring | Raceway Protection and NEC | Working with Metal Raceway | Inductance and Characteristic Impedance | Understanding Capacitance | History of the Ethernet | Twisting Data Conductors | NEC Article 800, Communications Circuits | NEC Article 810, Radio and Television Equipment | NEC Article 820, Community Antenna and Radio Distribution Equipment | NEC Article 830, Network-Powered Broadband | Troubleshooting Submersible Well Pumps | Wiring Healthcare Facilities | First Edition National Electrical Code 1897 | Books for Electricians | Links


Website Traffic