Users of electronic and computer equipment often experience sudden, sometimes unexplained crashing of their systems, resulting in frustrating and costly downtime while work is backed-up and regenerated. Frequently systems become corrupted to the extent that hardware has to be replaced.
Spikes and radio frequency interference (RFI)/electromagnetic interference (EMI) harmonic disturbances in the power supply are the main causes of this problem. Other causes are lightning discharges and induction or fluctuations in the power supply to the national grid, causing surge currents in excess of the tolerances acceptable to electronic and computer equipment.
Users are often under the wrong impression that equipment connected to an uninterrupted power supply (UPS) is protected from the effect of power surges. UPSs are designed to allow the user to close down systems to not lose data in the event of a power failure or to save data should the power supply fall below requirements.
Installing power conditioners that filter the mains supply and also separately protect data communication lines connected to the system is the only insurance against the damage caused by power surges. It is important, though, to understand the nature of these installations and the type of protection needed on different levels.
With Rhomberg's recently launched range of Hi-Power surge protectors, the strategy is to provide a cascade of protection barriers at appropriate points in a facility to absorb the energy of a surge and to divert it to ground. The following levels of protection have been identified for which appropriate products can be selected:
* Level 1: Coarse protection for peak surges up to 300 kA.
* Level 2: Medium protection for peak surges up to 50 kA.
* Level 3: Medium through-line protection with RFI/EMI filtration of up to 70 dB in the critical region of 150 kHz to 28 MHz.
Hi-Power surge protectors are based on the most up-to-date technology by using silicon carbide components instead of metal oxide varistors generally used in conventional systems. Silicon carbide has a significantly better thermal coefficient under stress conditions, thus being able to dissipate high thermal energy caused by power surges without suffering undue component stress. Silicon carbide devices furthermore maintain their original characteristics after repetitive conduction. This means that the product provides an overall protection facility which does not suffer the disadvantages of metal oxide varistor-based systems where components degrade after a relatively short period of time.
Hi-Power surge protectors have the advantage of operating at extremely short response times (less than 5 ns). Power surges are therefore clamped much faster than in conventional products, thus reducing the high destructive energy levels more efficiently. These products have been designed to offer protection on different levels, thereby filtering surges from point of entry right down to the final installation and are available in both AC and DC at various voltage ratings, in both single and three-phase.
Hi-Power is manufactured in South Africa by Rhomberg, an ISO 9001 quality company, designed in Rhomberg's EMC laboratory and with full back-up service. All products in the range comply with all known international, industrial, commercial and military standards. Rhomberg offers an on-site analysis to establish surge protection requirements.
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