Workspace Access For Large Equipment
Dec 1, 1997, Frederic P. Hartwell
If you design or install large equipment layouts, you need to watch out for special rules covering access to the required workspaces. Don't get confused...
Prime Movers, Voltage Regulators, And Power Generation-Part 1
Nov 1, 1997, Woodrow "Chip" Saccoccio, P.E.
AT A GLANCE: AC power generation is no longer the exclusive domain of utilities. Many contractors and non-utility maintenance people now have responsibility...
Using overcurrent protection for generator conductors
Dec 1, 1996, Hartwell, Frederic P.
What does the NEC actually require in the way of overcurrent protection for conductors supplied by a generator?One of the more confusing areas of the...
Critical data for sizing gen-sets
Nov 1, 1996, Olson, Gary L.
The complexities of modern loads, such as PWM power supplies, variable frequency drives, and other electronic equipment, place a whole new light on sizing...
Transient voltage spikes can harm solid-state starters.
Nov 1, 1996,
Why do these devices, a though generally reliable, sometimes fail unexpectedly?Since their introduction in the late 1950s, solid-state contactors and...
Calculating temporary power from multiple panels for multiple loads.
Nov 1, 1996, Lawrie, Robert J.
Q We recently had a problem providing temporary power to numerous pieces of 208V, single-phase equipment of various sizes. Sources of power were a number...
Power resources
Nov 1, 1996,
Transformers, engine-generators, power supplies, and batteries are important components of power distribution systems, and their improved performance...
Preventing condensation in 3-phase AC motors.
Nov 1, 1996, Ryan, Thomas J.
Here's how to select and install resistance heaters for reliable operation of motors in damp locations.You can avoid condensation problems in motors by...
What you need to know about operational amplifiers.
Oct 1, 1996, Rosandich, Ryan G.
Once thought to have outlived their usefulness, operational amplifiers are as popular today in control applications as they ever were.While many predicted...
Focus on the fundamentals of shielded MV power cable
Oct 1, 1996, Lisker, Lowell; Tucker, Gerry
MV power cables are perceived as commodities, but are all makes alike?Shielded, 90 [degrees] C (Type MV-90), medium-voltage(MV) power cane (5kV to 35kV)...
Controller ratings for elevator motors.
Oct 1, 1996, Hartwell, Frederic P.
Reduced starting currents don't justify derated controllers, but different motor time ratings may affect required horsepower ratings.An elevator service...
Fire pump sources to be reviewed
Sep 1, 1996,
The complaintThe essence of the complaint was that the wrong Technical Committee has been given jurisdiction over the material in Section 6-2 of the Fire...
Reliable power is money in the bank
Sep 1, 1996, Rowe, Louis E.
Electrical design based on total reliability results in smooth operations and client satisfaction at recently constructed bank site.When lightning strikes,...
What causes arcing at steam fitting?
Aug 1, 1996, Lawrie, Robert J.
Q We recently installed a new steam pressure reducing station in an existing 6-m. 150-lb steam line. After reinsulation of the pipe with foil-jacketed,...
'What to know about PID process controllers
Jul 1, 1996, Rosandich, Ryan G.
Hundreds of thousands of PID controllers are used each year to control industrial processes, and it is important to become familiar with their operation.What...
Premium-efficiency motors: soon they'll be law.
Jul 1, 1996, Lawrie, Robert J.
In a little more than a year from now, most of your new motors must meet new efficiency levels mandated by federal legislation.On October 24 of next year...
Submetering equipment pinpoints peak demand at foundry.
Jul 1, 1996, Parson, Ellen K.
In today's ever-changing economy, companies across the country are striving to lower operating costs and trim their budgets. As a result, an increasing...
Kitchen receptacles below countertops.
Jun 1, 1996, Hartwell, Frederic P.
The ability to allow kitchen countertop receptacles located below the countertop is more limited than some have interpreted.Important changes have been...
Unusual design issues involved in service change, part 2.
Jun 1, 1996, Hartwell, Frederic P.
A small multifamily dwelling service change uses some innovative construction techniques, some of which could be used in industrial applications.In addition...
What to know about PLC ladder diagram programming.
Jun 1, 1996, Rosandich, Ryan G.
When a PLC is used primarily to replace relays, timers, and counters, it's hard to beat the simplicity and usefulness of ladder diagram programming.Their...
