By Brian Persaud (IT Engineer) & Gerhard Ramsaroop (Manager, GuyanaNet)
E-mails: itbrian@gmail.com ,
gerhard.ramsaroop@gmail.com
For businesses, data is usually the most valuable part of the computer system. Lost data can result in lengthy system downtimes, high recovery costs, and lost productivity. Computers use electricity to create and store data and a stable, clean and reliable electricity supply is therefore essential. To this end, we need to guard against the following common power disturbances:
Sags or brownouts (low voltage) are usually short-term decreases in voltage as seen by lights dimming. They are typically caused by the start-up demands of fridges, air conditioners, water pumps, and large office equipment such as photocopiers and laser printers. Low voltage can starve a computer of the power it needs to function, causing freezing, crashing or hardware damage.
Blackouts are total power failures, and sudden, uncontrolled shutdowns could prevent your operating system (OS) from starting up normally and damage hardware.
Spikes or impulses are forceful, instantaneous, and dramatic increases in voltage and are considered the tidal waves (tsunami) of electric current. They are typically caused by lightning, but can also occur when power comes back after a blackout. Spikes can enter computers through your electrical outlet (point), network, coaxial, or telephone cable, resulting in catastrophic damage to hardware and possible loss of data.
Surges are short-term increases in voltage and occur when high electric demand equipment, such as air conditioners, fridges, and water pumps switch off. When this extra voltage is dissipated you may notice your lights brighten. Surges cause odd and unpredictable computer behaviour and stress delicate electronic components, often leading to their premature failure.
Electrical Noise disrupts the smooth sine wave output in electricity. Lightning, generators, radio transmitters, and industrial equipment can cause electrical noise. It shows up as flashes on monitors (CRTs) and TV screens, and introduces glitches and errors into software and data files.
Based simply on our experience, and without knocking other brands, we advise using APC products to guard against these disturbances. At a minimum, we recommend a line conditioner/stabiliser/voltage regulator, a UPS/battery backup, and a Performance or Network series surge protector (which also protect against spikes). These surge protectors have a let-through voltage of less than 40 volts, and are therefore more effective than the built-in surge protection on the UPS and line conditioners which have a let-through voltage of 330. Let-through voltage indicates the maximum excess voltage the surge protector will permit to reach your equipment.
Generally, because of their sensitivity, these higher-grade surge protectors are recommended for servers. However, we have found that they do extend your computer life and the time between repairs. We suspect because of the stresses and strains on our aged electricity grid, compounded by semi-industrial activities in areas where they should not be, that there are steady ripples of low-level surges. Over time, these could cause your computer to just crash for no apparent reason, and it is in this regard we have found these higher-grade surge protectors to be very effective at a client level in Guyana. Please read http://www.opalco.com/power-information/surge-protection/faq-surge-protection/ for more information. The UPS is not for blackouts only – since it kicks in at cut-off voltages of 88 and 139, it supplements your line conditioner which is designed to operate within the range of 85 to 140 volts.
This setup (high-grade surge protector, line conditioner, and UPS respectively) was first introduced by NT Computeac, one of Guyana’s largest IT retail and service companies, toward the end of 2004. During this time, motherboards began rapidly evolving to new sockets, SATA, gigabit network, 6-channel audio, etc., thereby becoming more sensitive to power problems. There are of course more effective protective equipment (APC and other) that can be used, but these are generally a lot more expensive. Investment in power protection should be commensurate with the value of your data and the cost of downtime.
Older computer systems tend to have a greater tolerance for power disturbances, but will eventually also go down. Once you have power problems you will experience some or all of the following: damaged hardware (memory, hard drive, motherboard, etc), system slowdown, numerous repair shop visits with no problems being found (since the power at repair shops is usually better), corrupted or lost data, corrupted software, erratic operation, and system lockups (freezing).
If you have a router and/or broadband modem, these will need to be plugged into your protective equipment as well. The input telephone, network or coaxial cable must be routed though the surge protector (this applies to your dial-up modem also) since surges through these cables can permanently damage your equipment.
Since most computers in Guyana conform to American NEC standards (which we are adopting anyway) you should use American duplex points, where the longer pin is the neutral, and not the live (hot). While wrong ‘polarity’ is generally harmless, it affects the ability of your power protection equipment to function. The only line afforded protective circuitry is the live, and if it is interchanged with the neutral you will be bypassing the protection. Always heed the red warning light on your protective equipment. Never have we ever come across a defective warning light; it is always as it says – site wiring fault (reversed polarity, overloaded neutral and/or missing ground) – remember, red means stop.
Ideally, your computer outlet(s) should be fed directly from the fuse or breaker panel and not be a part of a circuit with switches and points for other equipment. Use separate breaker panels for large office equipment (photocopiers, laser printers, etc.), ACs, fridges, etc. These separate panels/circuits should be independently grounded so as to minimise interference. Do not share the outlet your computer is plugged into with other devices such as a TV, or worse, a fridge. Use drop cords and extensions prudently, and opt instead to add permanent outlets as necessary – the small extra cost could save your computer, building, or even a life.
Grounding is critical. Regrettably in Guyana, some electricians do not bother with the grounding circuit; apart from the danger of occasional death, you would have wasted your money buying these surge protectors as they do not suppress surges per se, but divert (shunt) the excess voltage to the ground. The voltage in the ground circuit must therefore be monitored, and if it exceeds a few volts it could impede the diverted surges from flowing out. It is normal for there always to be some small voltage in your grounding, but if the connection to the ground rod is slack or corroded, the rod is of insufficient length and thickness, or the rod has exceeded its useful life, it could rise to unacceptable levels.
For 220 volt areas in Guyana there is the added headache of finding good transformers within the proliferation of those that are ungrounded, have faulty windings and/or reversed connections. These transformers are of course relatively inexpensive, but unfortunately, can prevent your protective equipment from functioning as they should. Especially when there is relatively high voltage in the neutral it could cause surge protectors to go up instantly in smoke and damage the circuit board on your UPS as well. Some of these faulty transformers feature built-in voltage regulators and are therefore even more attractive to the unsuspecting consumer.
The only suitable small transformer brands we know of are Mamita (Italian) found at Kanhai’s Guyana Electrical Agency and Magnetics (Chinese and Spanish) at Central Electronics. For a single computer system with a small inkjet printer, a 500VA transformer is usually sufficient.
