Fig : Repetitive votlage spikes


Fig 2 : Sinetamer protects VFDs from voltage spikes

The definition of a transient ‘transient’ (or ‘spike’ {i.e. the two terms are largely interchangeable}) is a temporary excess of voltage and current on an electrical circuit which has been disturbed in some way.

They can also be defined as a change in the fundamental (50Hz/60Hz) frequency. A transient ‘surge’ can contain thousands of volts and thousands of amperes with duration of nanoseconds to microseconds.

Transients voltages can be due to lightning, faulty power factor correction switching or faults and other disturbances on the power line, for example. Continuous voltage spikes can also be caused by the interaction between DC SCR drive line notching and stray cable and other capacitance in the system.

Whatever the cause, transient voltages can have a devastating effect of unprotected electronic equipment, especially exposed equipment containing capacitors in their input circuitry including small variable frequency drives (VFDs), fluorescent lighting and switched mode power supply capacitors. The results are usually spurious tripping at best or total destruction with all the operational downtime which can result from such failures. Motor winding insulation can also be stresses due to excessive transient voltages.

Sinetamer is a type of TVSS (transient voltage surge suppression) device specifically designed to protect switchboards and AC VFD and DC SCR drive. It is widely used worldwide including in the petro-chemical industries.

Repetitive voltage spikes on land based and offshore drilling rigs is not uncommon if SCR drives are utilised for drilling package duties. The line notching, due to commutation interacts with stray cable and other capacitance, often resulting in resonance within the notches. The result is voltage spikes (Fig 1) which disrupt or destroy capacitor based equipment such as switched mode power supplies and small VFDs, Sinetamer protects such equipment from the effects of the spikes (Fig 2).

Sinetamer encompasses the development of a fourth generation technology for surge and transient voltage protection. Sinetamer is a lot more than a typical TVSS (transient voltage surge suppressor) which can be found in electrical panels worldwide. It is an engineered solution, specifically designed for the ultra sensitive nature of electronic circuit boards (such as those used in VFDs, UPSs and PLCs) plus all variations of microprocessor based control systems.

Please click at the appropriate place to obtain more information on :

SineTamer catalogue click here – sinetamer-catalog-brochure

SineTamer for petro-chemical industries click here – sinetamerpetroleum