Nov. 13, 2008, PULLMAN, WA - Schweitzer Engineering Laboratories, Inc. (SEL) is now taking orders for two new products, the SEL-787 and SEL-487E Transformer Protection Relays. These are the first ...

Inrush currents associated with motor starting and transformer energizing can cause interaction problems with other loads in a facility or on the power system, particularly sags that trip loads.

A transformer switching onto a line can sometimes cause a circuit breaker to trip or a fuse to blow. This phenomenon occurs even if the transformer presents no load, such as when the secondary is open ...

This month in EC&M's forum for your power quality questions, Mark McGranaghan, vice president of consulting services, teams up with several other experts from EPRI-PEAC to address the topics of ...

Inrush currents arise when iron-core power transformers are energised under no-load conditions, producing transient peaks many times greater than the rated current. These surges stem from magnetic ...

Omicron has introduced a way to test current transformers at all lifecycle stages by using a testing method called "the modeling concept". The "traditional" way of testing a current transformer is to ...

Omron Electronic Components Europe has launched the G5Q-HR, the latest addition to the G5Q family of 10A PCB power relays. The new relays can achieve reduced power consumption and heat, and are 45 ...

However much care is taken, it is very difficult to keep all traces of transformer-induced hum out of the signal circuitry. It is highly irritating to find that despite the cunning use of low-noise ...

Transformers are very reliable devices and can provide service for a long time if regularly maintained and serviced. They’re also the single most costly item in any substation. To protect against ...

Although electromechanical relays have historically been the primary load switch in most applications, MOSFETs have been encroaching on the relay's territory in recent years as technology advances ...

Rectifiers and ac-dc power supplies employ large bulk capacitors. During power-up, these capacitors require a large amount of current to charge up, resulting in a large inrush current. This inrush ...