A problem with modern drives using high speed switching devices is the presence of common mode voltages (CMVs) in the variable frequency drive (VFD) feed. Doing away with the isolation transformer reduces the size, weight and cost of the VFD. While the electronics involved are more complex and therefore more costly, the overall benefits outweigh […]
This article examines how the intelligence within variable speed drives (VSDs) can be leveraged to perform predictive maintenance to improve plant uptime. VSDs were introduced to the market several years ago and have since proliferated across many industries. Despite their popularity, much work still needs to be done to fully integrate these technologies to develop […]
The selection of AC induction motors for cement mill applications, with reference to fan, kiln and vertical mill applications. Although motors may appear to be the least complicated component in the specification of cement mill equipment, cement plant applications present an immense matrix of application criteria to specify, design and build motors properly. Operating conditions […]
Substations and distribution boards in both the utility and industry sector are under increasing pressure to reduce space usage and cost, while maintaining safety and integrity. Switchgear is the main space occupant, and efforts at space reduction are focused on reducing both the volume and footprint occupied. Solid insulation switchgear offers reduced space and […]
SF6 gas, used as a dielectric medium in circuit breakers and switchgear, has a global warming potential 24 000 times greater than CO2 and some of its by-products were used as chemical weapons in World War I. In life, in business, in the ordinary course of doing things, there is a certain level of risk […]
As the cost of downtime continues to rise, engineers and electrical distribution stakeholders need a strategy for either upgrading or replacing ageing switchgear. This article discusses the benefits of investing in an upgrade strategy. The reliable flow of electricity allows today’s “wired” global business environment to thrive and grow. The cost of downtime is now calculated […]
Using VSDs with direct torque control increases motor torque response dramatically. The performance of asynchronous AC motors in today’s applications comes from modern electronic controls such as variable-speed drives (VSDs) and accurate motor models whose sophisticated control algorithms can be executed rapidly by high-performance digital signal processors. Electric motors are often at the spearhead […]
Accidental or naturally occurring explosive atmospheres, which occur as a result of the process, activity or product in the environment, are encountered in many industrial and mining situations. In these conditions, a single small spark can initiate a large explosion, and care needs to be taken when using electrical equipment in these environments. In […]
For decades, the unique properties of sulfur hexafluoride (SF6) have made it popular as an insulation and switching medium for electrical switchgear. SF6 is a greenhouse gas and there are life-cycle management costs associated with its use. For some years, ABB has been conducting research into alternatives with lower environmental impact but with insulation […]
Owners and facility managers must keep their equipment at peak performance, leaving them tasked with managing the maintenance process while decreasing maintenance costs. The National Fire Protection Association standard, NFPA 70B Recommended practice for electrical equipment maintenance, states: “Electrical equipment deterioration is normal, but equipment failure is not inevitable. As soon as new equipment is […]
