Electric Motor
Basic electrical design of a PLC panel (Wiring diagrams)
It is uncommon for engineers to build their own PLC panel designs (but not impossible of course). For example, once the electrical designs are complete, they must be built by an electrician. Therefore, it is your responsibility to effectively communicate… Read more
Feb 27, 2017 | By Edvard Csanyi
Low Voltage
Measurement of N–PE loop resistance in TN, TT and IT systems
Up-to-date test instruments, with built in modern electronics, can measure loop resistance even between the neutral N and protection PE conductors in spite of possible high currents in the neutral conductor. The current, which is driven by phase voltages through… Read more
Feb 24, 2017 | By Edvard Csanyi
Energy and Power
Do you know what ground potential rise is? It’s really important.
First of all, ground potential rise is very important and very dangerous event. The grounding engineer will be required to develop safety systems to protect any personnel working where ground potential rise hazards are known to exist. Federal law mandates… Read more
Feb 22, 2017 | By Edvard Csanyi
Cables
Guidelines for high potential (Hi-Pot) DC testing of medium voltage cables
This technical article provides general guidelines for high potential “Hi-Pot” DC testing of MV power cables. All tests made following cable installation and during the warranty period must be performed in accordance with the applicable specifications. Testing should be performed… Read more
Feb 20, 2017 | By Edvard Csanyi
Energy and Power
5 good examples of locking out HV/MV/LV structures and equipment
In all cases the choice of locks and safety positions requires prior analysis of the locking sequence to be applied in order to correctly define the requirement and clearly identify the related risks. Remember that “electric” locking systems are never… Read more
Feb 17, 2017 | By Edvard Csanyi
Energy and Power
How a three-phase power transformer responds to harmonics
The way in which a three-phase transformer responds to harmonics depends on the connection configuration used. For a star-star configuration, any imbalance in the phase currents results in the star point being electrically displaced and the phase to neutral voltages… Read more
Feb 15, 2017 | By Edvard Csanyi
Electric Motor
Detailed calculation of currents and power according to the type of load
Currents and power analysis are key factors in any design or redesign of an installation they will enable the source(s) to be sized according to the purpose of the installation, the intended use of the circuits and the receivers to… Read more
Feb 13, 2017 | By Edvard Csanyi
Electric Motor
Practical checks for motor selection on AC adjustable speed drive systems
Important checks to consider in the motor selection for AC adjustable speed drive system: Determine motor enclosure requirements Determine motor torque and speed requirements: Operating speed range Breakaway torque Determine accelerating and decelerating requirements (time and load) Overload Determine type… Read more
Feb 10, 2017 | By Edvard Csanyi
Energy and Power
Four typical designs for connecting generator set(s) to the low voltage system
Many different system designs are possible, but for highest reliability, systems are typically configured so that generator set(s) are connected at low voltage, with the minimum number of transformers and circuit breakers between the generator set and load to be… Read more
Feb 08, 2017 | By Edvard Csanyi
Energy and Power
The easiest way to measure ground resistance using clamp meter, but be carefull!
The ground clamp meter / tester is an effective and time-saving tool when used correctly because the user does not have to disconnect the ground system to make a measurement or place probes in the ground. The method is based… Read more
Feb 06, 2017 | By Edvard Csanyi
Energy and Power
Single line diagrams of emergency and standby power systems with automatic transfer switch (ATS)
Emergency and standby power systems are generally designed into the over-all electrical system for one of the following two reasons: Legal Requirements – As required by the NEC, NFPA 101, NFPA 99 and other local, state, and federal codes and requirements…. Read more
Feb 03, 2017 | By Edvard Csanyi
Electric Motor
Ladder logic for special motor control circuits – jogging and plugging
Ladder logic is often used to implement various motor control circuits. Beside standard motor control circuits, there are also special control circuits designed to allow jogging (brief energization of the motor to adjust its positioning) or to prevent plugging (sudden… Read more
Feb 01, 2017 | By Edvard Csanyi
