פורסם בתאריך December 22 2020
On July 13th 1977, a blackout accord in New York City. The power stopped for about 25 hours. This blackout happened due to 4 lightning strikes hitting high power lines and a power plant. Due to this blackout a 300 million USD damages were reported (from Wikipedia). This phenomena of losing a power source is a well-known one and we have many measures to deal with it: Generators that backup the entire power supply to the site or facility; or a UPS system that backup specific computers or systems. However, there are other phenomena related to our power supply that affect different systems and coping with their phenomena can increase the outcome of the system, save cost and make work more efficient.
Powervar, an AMETEK company, specialized in developing and manufacturing UPS and UPM system, surveyed 11 of the phenomena that affect system performances and the ways to handle it. The Powervar system is based on steps of ABC’s of power conditioning.
Each step of the system of Powervar handles different phenomena and combining all the steps allows the system to remain stable, work longer and with higher yield and reliability.
Power surges can send your expensive computers and other electronic equipment to the dumpster. Surges can contain substantial amounts of energy, causing outright catastrophic component failure. Some surges contain smaller energy levels that erode components microscopically, leaving them in a weakened state. Surges are addressed with a surge diverter (A) — a device that diverts excessive voltages away from the system by shunting them to ground. Although the surge diverter protects against these major power surges, transient voltages smaller than 250– 300 volts usually slip by the surge diverter, causing equipment to be exposed to degrading energy spikes over the long term.
Surge diverters (as well as noise filters) shunt disturbance energy to ground, resulting in a neutral-to-ground (common-mode) voltage — a situation that’s highly disruptive to digital and microprocessor-based technologies. The low-impedance isolation transformer (B) provides a mechanism for bonding the electrical neutral to the ground in a way that is acceptable to electrical codes. This enhances the operation of surge diverters and noise filters because the transformer bond prevents the formation of neutral to ground voltage. The isolation transformer also acts as an excellent “cushion” against power disturbances in general.
Power line noise filters (C) address the disturbances that slip by the surge diverter along with the low-amplitude, high-frequency noise that the surge diverter is not designed to handle. Typically these disturbances are caused by nearby electrical “neighbors” such as lighting ballasts, appliances, motors, electrical HVAC controls, and even other computer power supplies. Not only can noise wear away electronic components, it can also interfere with the reliable operation of digital circuits. Like surge diverters, noise filters shunt power disturbances to ground.
Voltage Swells And Sags
Swells and sags can originate outside of a facility but can also be created by equipment used inside the facility. For some electronic equipment with older, linear power supply technology, well-regulated voltage is critical to proper performance. Fortunately, most equipment uses newer-style switched mode power supplies, which are largely immune to voltage irregularities. The need for voltage regulation is infrequent, but when necessary, voltage swells and sags are eliminated with a voltage regulator (D). Various regulation technologies are available, and careful consideration is necessary to select the one that’s best suited for the application.
If power outages are the problem, an uninterruptible power supply [UPS] (E) will be the answer. A UPS converts DC energy stored in batteries into AC energy to power the electronic load temporarily. All UPS products are not equal. Some UPS products are online and others are standby, and some have true sine wave outputs and others have square wave or modified square wave outputs. Some units provide power conditioning and most do not. POWERVAR UPM products provide conditioned, sine wave, AC power — the kind your equipment was designed to use..
Unstable AC Frequency
AC power in North America is generated at a frequency of 60 Hz, while in Europe and many other locales, AC power is generated at 50 Hz. In developing countries, or where power is sourced from an electrical generator, the frequency may not always be stable. In such cases, a frequency regulator (F) is required. An online UPS or AC inverter is one answer for ensuring stable-frequency AC power for predictable equipment performance.
When electronic systems are connected into a network, multiple branch electrical circuits are involved in powering the various network components. Along with these different circuits come different safety ground impedances. The result is the formation of “ground loops” in which noise currents flow in the loops created by the grounding and shielding conductors of the signal cables used to connect the network. These loop currents cause communication errors and data packet collisions. Large loop currents will easily destroy the communication drivers on interface cards. For many years, the only solution for addressing ground loop issues was the dedicated-isolated electrical circuit. POWERVAR’s Ground Guard technology (G) is highly effective in preventing the formation of ground loops and eliminating the need for special dedicated-isolated electrical circuits.
Voltage Spikes And Impulses
Like electrical noise, this virus is also spread by equipment inside your facility. When elevators, motors or air conditioners stop and start, they can cause sudden large increases in voltage inside the electrical system. Other causes include electric utility switching and lightning strikes (which can cause transients so intense they literally “blow up” sensitive electronics). Unlike surge diverters, which can only slow down or weaken this virus, a POWERVAR system stops it dead by giving you complete protection from small and large transients.
This virus infects your system via a pathway you’d least expect: the backdoor. Even though it’s not an AC power connection, damaging electrical disturbances can enter electronic systems through modem and phone lines, network connections, and I/O cables. Fiber optic connections are one means of protection, but if your system uses ordinary communications wiring and connections, you need to immunize it against this often unrecognized but very dangerous virus. Once again, POWERVAR is your source for complete protection.
The list above is partial, each and any part of the system can have similar or additional phenomena that can reduce performances. Powervar offer a wide range of solutions to these phenomena and other ones related to the power supply and improvements. Some of the solutions can be modified to customer’s need.
This article was prepared by Meidad Peleg from Medital, Powervar representative in Israel
כתובת מייל: Comotech@medital.co.il
טלפון ראשי: 073-2000290
כתובת מייל: Meidad@medital.co.il
טלפון ישיר: 073-2000211
כתובת מייל: firstname.lastname@example.org
טלפון ישיר: 073-2000228
כתובת מייל: Yonatan@medital.co.il
טלפון ישיר: 073-2000235
כתובת מייל: Moni@medital.co.il
טלפון ישיר: 073-2000213
כתובת מייל: Arie@medital.co.il
טלפון ישיר: 073-2000203