The basics of electrical troubleshooting. (part 2)
Nov 1, 1996,
Typical problem areas with CPTs include open circuits, partial shorts, complete shorts, and grounded windings. Your first check should be at the primary...
The basics of electrical troubleshooting
Oct 1, 1996,
We're talking about line-to-ground faults that may damage equipment. The NEC, per Sec. 215-10, requires that ground-fault protection for equipment (GFPE)...
Sizing continuously loaded conductors made simple.
Aug 1, 1996, Hartwell, Frederic P.
Given a calculated load that is at least partially continuous, this updated four-part test assures that the conductors are correctly chosen.Selecting...
Sizing a circuit breaker.
May 1, 1996, Pauley, Jim; Young, Sandi
Circuit breakers are designed to carry 100% of their rated current while the NEC dictates an 80% application. Why the difference?One of the most often...
The basics of molded case circuit breakers.
May 1, 1996,
The traditional molded-case circuit breaker uses electromechanical (thermal magnetic) trip units that may be fixed or interchangeable. An MCCB provides...
The basics of capacitance.
Apr 1, 1996,
If we take two metal plates, separate them with a dielectric (insulator), and apply a DC voltage between the plates, current will not be able to cross...
Understanding IG wiring
Feb 1, 1996, Lewis, Warren H.
The risk/benefit situation of SG and IG wiring methods has many variables, all depending upon the specific application and situation.There's plenty of...
Understanding high performance UTP cable
Jan 1, 1996, Knisley, Joseph R.
Contractors and users now have a valid reference for pass/fail criteria when field testing installed data/communications cabling.Installers and users...
Understanding IG receptacles
Jan 1, 1996, Lewis, Warren H.
IG-style wiring is interesting because it's so unpredictable, from the standpoint of what it does and doesn't do. It may or may not be a good thing at...
Understanding PLC networks
Jan 1, 1996,
Knowing the available PLC network options and their best applications will ensure an efficient and flexible control system design.The programmable logic...
Knowing the basics of PLCs
Oct 1, 1995, Hee, Robert B.
Programmable logic controllers provide dependable, high-speed control and monitoring demanded by a wide variety of automated applications.Programmable...
The basics of solid state devices
Sep 1, 1995,
An LED generates light by using its semiconductor materials. Basically, the presence of electrical current forces the electrons and holes within the P-...
The basics of solid state devices.
Aug 1, 1995, DeDad, John A.
A device frequently used in solid-state equipment such as lighting dimmers and variable speed controls is the silicon controlled rectifier (SCR). As shown...
An introduction to the decibel.
Jul 1, 1995, Lewis, Warren H.
While modern test instruments can compute decibels for us, we should know what a decibel is and how to manually calculate gain or loss.We all have a direct,...
The basics of solid-state devices.
Jul 1, 1995, DeDad, John A.
Another workhorse of electronic equipment is the transistor. There are two types of transistors commonly used: PNP and NPN. As shown in Fig. 1, the PNP...
The basics of solid state devices
Jun 1, 1995, DeDad, John A.
Many industrial control systems use a device that changes one form of energy to another; this device is called a transducer. Typical transducers convert...
Understanding sample rate.
Jun 1, 1995, Price, Ken; Saxe, Chuck
What is sampling rate and why is it important in the selection of test and measuring equipment?What is sampling rate? Furthermore, why is it important?...
The basics of solid-state devices. (part 2)
May 1, 1995,
A zener diode is a type of diode that acts as a voltage regulator when installed by itself or with other semiconductor devices. This device is unique...
The basics of solid-state devices
Apr 1, 1995,
A diode, in lay terms, is a semiconductor that has two electrodes and that passes electric current in one direction only. An ideal diode offers no impedance...
Understanding modern motors and controllers.
Mar 1, 1995, Lawrie, Robert J.
Included are the latest developments, fundamentals, NEC rules, standards, special features, and other important details on motors and controllers.Motors...
The basics of 400-Hz power systems.
Mar 1, 1995, Dedad, John A.
Although the use of 400-Hz power is certainly declining, especially in mainframe computer power systems, some existing systems may need upgrading because...
Sizing manholes.
Feb 1, 1995,
We were asked to comment on an installation similar to the one pictured in the drawing. Half of the conductors coming in from the 24-duct bank turn out...
