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[ { "title": "READ | Thumbs up for Back-Up Power", "nid": "477", "body": "\u003Cp\u003E\u003Ca href=\u0022https://www.magnetgroup.co.za/download/magnet-back-up-power-catalogue.pdf\u0022\u003E\u003Cimg alt=\u0022Back-up power\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u00226fa58f62-dd21-41dc-a87b-3004bff40048\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/newsletterbanner.png\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003ELoad shedding isn\u2019t going away for good \u2013 we know this. But, do you also know what alternative power supplies to use during these pesky power outages? We give a big thumbs-up for Back-Up Power!\u003C/p\u003E\n\u003Cp\u003EIn this quick article, we address some common questions about back-up power and other alternative power supplies...\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EWhat does a back-up system comprise of? \u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EA back-up system typically consists of\u003C/p\u003E\n\u003Cul\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EAn inverter to convert the DC battery power into usable AC mains power\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EA battery bank to store power for later use\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EA battery charger to charge the batteries\u003C/li\u003E\n\u003C/ul\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EClick \u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-solar/news.php?type=articles\u0026amp;name=NEW-SERIES--Batteries---Sizing-and-Selection\u0022\u003E\u003Cstrong\u003EHERE\u003C/strong\u003E\u003C/a\u003E to learn more about batteries.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EHow do back-up systems work?\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe unit is permanently connected to utility power. While utility power is present, the battery charger recharges the batteries and keeps them fully charged. The equipment you want to back up is also permanently connected via the system. When a power outage occurs, the back-up system automatically switches over via an extra fast transfer switch to the inverter, which will continue to provide power to the equipment within 15 msec. This is extremely fast, so much so that standard equipment like TVs, DSTV decoders, microwaves, fans, etc. are unaffected.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EWhen utility power returns, the whole procedure is reversed and the unit will switch back to utility power and will automatically start re-charging the batteries. Your equipment remains connected to the system even when power is restored. The whole process is fully automatic.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EHow is a system sized? \u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003ENote that the size of the system will depend on the equipment to be powered during load shedding. It is also wise to consider the duration of power outages that you typically experience in your area.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EWe have a\u00A0\u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-solar/news.php?type=articles\u0026amp;name=DOWNLOAD--Size-your-System-with-our-Power-Profile-Tool\u0022\u003E\u003Cstrong\u003EPower Profile tool\u003C/strong\u003E\u003C/a\u003E.\u00A0\u003Cbr /\u003E\n\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Back-up Power Enquiry\u0022\u003E\u003Cstrong\u003ECHAT\u003C/strong\u003E\u003C/a\u003E to us for help on\u00A0determining\u00A0the size of the system you require!\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EWhen should a UPS be considered? \u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E100% automatic back-up power is the desired solution for homes, guesthouses, farms, and small businesses where data capture/transfer is not critical. UPS systems are the ideal solution to protect servers and computers.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EClick \u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-solar/news.php?type=articles\u0026amp;name=LEARN--Understanding-UPS-systems\u0022\u003E\u003Cstrong\u003EHERE\u003C/strong\u003E\u003C/a\u003E to learn more about UPS systems.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EWhat are some advantages of back-up power over a generator? \u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EBack-up power systems can be installed virtually anywhere, unlike generators. Not only are generators noisy, they also typically require manual start-up. If you don\u2019t mind the possibility of having to go outside in the dark to start your generator, perhaps you will mind the fact that generators require constant re-filling and maintenance\u2026\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EWhat should be considered before investing in a back-up system?\u003C/strong\u003E\u003C/p\u003E\n\u003Cul\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EWhile fridges and freezers can be powered by backup power, is it really necessary to add these on to your system especially if the doors stay shut?\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003ESwitch from incandescent or dichroic downlights to LEDs or CFLs \u2013 these lights can be added onto your back-up system\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EGeysers consume a lot of power. It\u2019s not worthwhile adding this on to your back-up system especially considering that you may only lose 2\u00B0C in water temperature during the 2-2.5 hours load shedding\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EAir-conditioning units and underfloor heating can be powered by a backup system, but will drastically increase costs\u003C/li\u003E\n\u003C/ul\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EConsidering a back-up power solution for your home or business?\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EAre you looking to upgrade your existing back-up power solution?\u00A0\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EWhether you want a battery, solar, generator or\u00A0 even all three...\u00A0\u003Cstrong\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Back-up Power Enquiry\u0022\u003ECHAT \u003C/a\u003E\u003C/strong\u003Eto us!\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EAnd remember to \u003Ca href=\u0022https://www.magnetgroup.co.za/download/magnet-back-up-power-catalogue.pdf\u0022\u003E\u003Cstrong\u003EDOWNLOAD\u003C/strong\u003E\u003C/a\u003E our back-up power catalogue to view our range and prices.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u00A0\u003C/p\u003E\n", "created": "Mar 2021", "terms": "Back-Up Power, Education" }, { "title": "NEW SERIES | Understanding Variable Speed Drives - pt 2", "nid": "475", "body": "\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cimg alt=\u0022Factory \u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022753c38de-7d66-4e18-a275-146c10888dfb\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/emailer_0.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp\u003EIs there a device that can reduce downtime whilst increasing the lifespan of your \u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-electrical/index.php\u0022\u003E\u003Cstrong\u003Eelectrical\u003C/strong\u003E\u003C/a\u003E motor?\u003C/p\u003E\n\u003Cp\u003EIn our NEW series, we\u2019re unpacking Variable Speed Drives.\u003C/p\u003E\n\u003Cp\u003EIn \u003Ca href=\u0022https://www.magnetgroup.co.za/news.php?type=articles\u0026amp;name=NEW-SERIES--Understanding-Variable-Speed-Drives---pt-1\u0022\u003E\u003Cstrong\u003EPart 1\u003C/strong\u003E\u003C/a\u003E, we introduced you to the basic principle of operation of a VSD, and touched on their key benefits\u003C/p\u003E\n\u003Cp\u003EIn Part 2, we give an overview of the types of VSD\u2019s, and delve into how a VSD works\u003C/p\u003E\n\u003Cp\u003EWatch this space to catch the full series!\u003C/p\u003E\n\u003Cp\u003E\u00A0\u003C/p\u003E\n\u003Cp\u003E\u003Cstrong\u003E\u003Cu\u003ETypes of VSD\u2019s\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp\u003EThe three common types of VSD\u2019s are:\u003C/p\u003E\n\u003Col\u003E\n\u003Cli\u003E\u003Cstrong\u003ECurrent Source Inversion (CSI)\u003C/strong\u003E \u2013 used in signal processing and industrial power applications. It produces a clean current waveform but requires expensive inductors and causes cogging below 6 Hz.\u003Cbr /\u003E\n\t\u00A0\u003C/li\u003E\n\u003Cli\u003E\u003Cstrong\u003EVoltage Source Inverters (VSI)\u003C/strong\u003E \u2013 has a poor power factor, causes cogging below 6 Hz and are non-regenerative.\u003Cbr /\u003E\n\t\u00A0\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EPulse-Width Modulation (PWM)\u003C/strong\u003E \u2013 used most commonly in industry because of high input power factor, no motor cogging, higher efficiency and lower cost.\u003C/li\u003E\n\u003C/ol\u003E\n\u003Cp\u003E\u00A0\u003C/p\u003E\n\u003Cp\u003E\u003Cstrong\u003E\u003Cu\u003EPulse-Width Modulation VSD\u2019s\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EA PWM VSD works by using a series of voltage pulses of different lengths to simulate a sinusoidal wave. These pulses are timed in such a way so that the time average integral of the drive outputs a sinusoidal wave. Insulated Gate Bipolar Transistors are the electronic components used to generate these voltage pulses.\u00A0\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe below\u00A0diagram depicts a Sinusoidal Wave created by a comparator.\u00A0\u00A0\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cimg alt=\u0022Sinusoidal wave\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022e00f0e84-559c-4082-9f83-b4c102be9806\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/1.%20PWM%20sinusodial%20wave.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp class=\u0022MsoNormal\u0022 style=\u0022text-align:justify\u0022\u003E\u003Cspan lang=\u0022EN-US\u0022 style=\u0022font-size:11.0pt;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;mso-ascii-theme-font:\u0026#10;minor-latin;mso-hansi-theme-font:minor-latin;mso-bidi-theme-font:minor-latin;\u0026#10;mso-ansi-language:EN-US\u0022 xml:lang=\u0022EN-US\u0022 xml:lang=\u0022EN-US\u0022\u003E\u003Cspan style=\u0022mso-tab-count:1\u0022\u003E\u00A0\u00A0\u003C/span\u003E\u003C/span\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EHow Does a VSD Work?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe first stage of operation for the VSD is the converter. This converter consists of 6 diodes that allow current to flow in only one direction (indicated by the arrow in the diode symbol).\u003C/p\u003E\n\u003Cp class=\u0022MsoNormal text-align-justify\u0022\u003E\u003Cspan lang=\u0022EN-US\u0022 style=\u0022font-size:11.0pt;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;mso-ascii-theme-font:\u0026#10;minor-latin;mso-hansi-theme-font:minor-latin;mso-bidi-theme-font:minor-latin;\u0026#10;mso-ansi-language:EN-US\u0022 xml:lang=\u0022EN-US\u0022 xml:lang=\u0022EN-US\u0022\u003E\n\u003C/span\u003E\u003C/p\u003E\n\u003Cp\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u00A0The below diagram depicts a VSD Converter and Output Waveform.\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cimg alt=\u0022VSD Converter and Output Waveform\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u002242ddb456-cb4b-4741-a7a9-4344d3bc2207\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/2.%20VSD%20Converter%20and%20Output%20Waveform.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp\u003EThe electricity will alternate in the supplied phases but the diodes will only allow the peak phase to pass.\u003C/p\u003E\n\u003Cp\u003EThese diodes operate in the following manner:\u003C/p\u003E\n\u003Cul\u003E\n\u003Cli\u003EWhen A-Phase voltage is more positive than B or C phase voltages, then the diode will open and allow current to flow.\u003C/li\u003E\n\u003Cli\u003EWhen B-phase voltage becomes more positive than A-phase voltage, then the B-Phase diode will open, and the A-Phase diode will close.\u003C/li\u003E\n\u003Cli\u003EThis process also applies for the negative side of the waveform resulting in six current pulses as each diode blocks and allows the phases to pass.\u003C/li\u003E\n\u003C/ul\u003E\n\u003Cp\u003E\u00A0\u003C/p\u003E\n\u003Cp\u003EAssuming that the drive is in operation using a 480V\u003Csub\u003Erms\u003C/sub\u003E supply. Then the V\u003Csub\u003EPeak\u003C/sub\u003E of the supply is 679V. As seen in the picture above, the VSD DC bus has a DC voltage with an AC ripple. The below diagram depicts a DC Bus and Voltage Waveform at the DC Bus.\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-electrical/index.php\u0022\u003E\u003Cimg alt=\u0022DC Bus\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022073bac69-feea-446d-8fa4-de2838ccca48\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/3.%20DC%20Bus%20and%20Voltage%20Waveform%20at%20the%20DC%20Bus.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp\u003EThe AC ripple on the DC bus is removed by adding a capacitor resulting in the voltage on the DC bus being approximately 650V. The actual voltage is dependent on the AC supply line, the level of voltage unbalance on the power system, the motor load, the impedance of the power system and any reactors or harmonic filters on the drive.\u00A0 The AC to DC conversion is done by the \u201Cconverter\u201D whilst the DC to AC conversion is done by the inverter. The below diagram depicts a Converter, DC Bus, Inverter and Output Waveform Supplied to Motor.\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-electrical/index.php\u0022\u003E\u003Cimg alt=\u0022Converter\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022f93e3f5b-58c3-4641-be6f-ff5157e84a93\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/4.%20Converter%2C%20DC%20Bus%2C%20Inverter%20and%20Output%20Waveform%20Supplied%20to%20Motor.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe inverter converts the rectified and conditioned DC back into an AC supply of variable frequency and voltage. This is normally achieved by generating a high frequency pulse width modulated signal of variable frequency and effective voltage. Semiconductor switches are used to create the output, the most common being the Insulated Gate Bipolar Transistor (IGBT). We can control the frequency by controlling the timing of the switches (IGBT). As seen in the picture below, a VSD does not produce a sinusoidal output but a rectangular waveform which is adequate for a motor. The below diagram depicts the Output Waveform from a VSD at Various Frequencies.\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022https://www.magnetgroup.co.za/\u0022\u003E\u003Cimg alt=\u0022Output waveform\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022714a1342-11cb-4fb4-9c27-5b3e42f6c2d8\u0022 height=\u0022295\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/Updated%20graph.png\u0022 width=\u0022360\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EProtection of VSD\u2019s\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EShort circuit protection of variable speed drives is obtained by using fast acting fuses in front of the drive to minimize the let through energy in the event of a fault.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EDo you need advice on the best VSD for your specific application?\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cstrong\u003ECHAT\u003C/strong\u003E\u003C/a\u003E\u00A0to our team of electrical experts now!\u003C/p\u003E\n", "created": "Mar 2021", "terms": "Electrical, Education" }, { "title": "NEW SERIES | Understanding Variable Speed Drives - pt 1", "nid": "474", "body": "\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cimg alt=\u0022factory\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u00220af1e1b9-6d71-4384-bef0-8a1ffde9a594\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/Emailer.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EDo you see your plant constantly on a breakdown as a result of a motor failure? Are you forced to spend a vast amount of time replacing electrical motors that are essential to the productivity of your plant?\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EIs there a device that can reduce downtime whilst increasing the lifespan of your electrical motor?\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EIn this NEW series, we discuss Variable Speed Drives as an essential component to increase the lifespan of your electrical motors and reduce maintenance-associated downtime.\u00A0\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EIn part 1, we give you an overview of VSD\u2019s \u2013 what they are, their benefits and the protection they offer to a motor.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EWatch this space to catch the full series!\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EWhat are Variable Speed Drives?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EA Variable Speed Drive (VSD) or Variable Frequency Drive (VFD) is a controller that is used to drive an electric motor. It does this by converting the frequency of the supply electricity into a variable frequency output. The variation in frequency enables the drive to control the operation of the motor. A low frequency will cause the motor to operate at a low speed, whilst a higher frequency enables it to operate at a faster speed.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe diagram below depicts the basic principle of operation of a VSD.\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cimg alt=\u0022Basic principle of operation of a vsd\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022fe530db7-2ed8-41ee-88ac-30d6d7accdfe\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/Basic%20principle%20of%20operation%20of%20a%20VSD.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EHow is the Frequency and Speed related in an Asynchronous Motor?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe synchronous speed of an electrical induction motor is determined by:\u003C/p\u003E\n\u003Col\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EThe frequency of the supply\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EThe number of poles in the motor\u003C/li\u003E\n\u003C/ol\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EIt can be calculated using the following equation:\u003C/p\u003E\n\u003Cp\u003E\u003Cimg alt=\u0022Calculation 5\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022e3f8c9fb-805e-4782-8a24-d3aa7849687a\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/Calculation.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EWhere:\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003En = shaft rotation speed (rpm)\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003Ef = frequency of electrical power supply\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003Ep = number of poles\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EWhat are the Key Benefits of Using a VSD?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Col\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003EEnergy costs can be reduced\u003C/strong\u003E\u003Cbr /\u003E\n\tIf an application requires a motor to not run at full speed, then a VSD can be used to match the speed of the motor driven equipment to the load requirement.\u003Cbr /\u003E\n\t\u00A0\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022 value=\u00222\u0022\u003E\u003Cstrong\u003EIncrease Production Using Stricter Process Control Measures \u003C/strong\u003E\u003Cbr /\u003E\n\tOperating a motor at the most efficient speed for the application will cause fewer mistakes to occur resulting in production and profit levels increasing.\u003Cbr /\u003E\n\t\u00A0\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022 value=\u00223\u0022\u003E\u003Cstrong\u003EExtension of Equipment Life and Reduction in Maintenance\u003C/strong\u003E\u003Cbr /\u003E\n\tEquipment will last longer and will have less downtime due to maintenance when the motor is controlled using a VSD. \u00A0Due to the VSD controlling the frequency and voltage.\u003C/li\u003E\n\u003C/ol\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EOptimizing motor control systems using VSD\u2019s can reduce energy consumption in your plant by as much as 70%.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EWhat Protection does a VSD Provide to a Motor?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EA VSD provides the following complex protection mechanisms to a motor:\u003C/p\u003E\n\u003Col\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EStall prevention\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003ECurrent limitation \u0026amp; overcurrent protection\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EShort Circuit Protection\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EUnder-voltage and Overvoltage Protection\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EGround Fault Protection\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EPower supply phase failure protection\u003C/li\u003E\n\u003Cli class=\u0022text-align-justify\u0022\u003EMotor thermal protection through sensing of the motor winding temperature.\u003C/li\u003E\n\u003C/ol\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u00A0\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EIn part two of the series, we answer the question \u201CHow does a VSD work?\u201D We also mention the various types of VSD\u2019s and the protection of VSD\u2019s. The series ends with sizing VSD\u2019s and a comparison of VSD\u2019s with soft starters. Stay tuned to catch the full series!\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u00A0\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003ENeed advice on the best VSD for your specific application? \u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Electrical Enquiry\u0022\u003E\u003Cstrong\u003ECHAT\u003C/strong\u003E\u003C/a\u003E to our experts now!\u003C/p\u003E\n", "created": "Mar 2021", "terms": "Electrical, Education" }, { "title": "READ | Load Shedding is Back!", "nid": "476", "body": "\u003Cp\u003E\u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-solar/index.php\u0022\u003E\u003Cimg alt=\u0022Load shedding\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u00220300c500-ece9-460a-b9c2-d945f97c3321\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/eskom-2156-1120-2.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp\u003EJust when you thought you were out of the dark, you get that dreaded ping from your SePush app \u2013 a sobering reminder that load shedding is not going away, not any time soon.\u003C/p\u003E\n\u003Cp\u003E\u003Cstrong\u003E\u003Cu\u003EYour load-shedding woes are far from over\u2026\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp\u003EStage 2 load shedding was implemented yesterday. Eskom has stated that they have to deliberately cut electricity to many communities in the country, in an effort to ease pressure on the already constrained grid.\u003C/p\u003E\n\u003Cp\u003EThe Power Utility Department has implemented load shedding until Friday, with a high possibility of it continuing throughout the weekend.\u003C/p\u003E\n\u003Cp\u003EEskom claims that this latest round of power cuts are due to \u201Closs of generation capacity and to replenish emergency generation reserves.\u201D\u003C/p\u003E\n\u003Cp\u003EWhen the Utility implements load shedding, there are various instances which could bring the decision about, such as:\u003C/p\u003E\n\u003Cul\u003E\n\u003Cli\u003EStagnated supply of electricity due to poor maintenance of power lines\u003C/li\u003E\n\u003Cli\u003EReduced production by equipment failure and/or damage to power generating stations (such as nuclear power stations, coal plants etc.)\u003C/li\u003E\n\u003Cli\u003ESudden power failures and downtime and/or widespread blackouts\u003C/li\u003E\n\u003Cli\u003EReduced production of renewable energy due to climate / weather conditions\n\u003Cul\u003E\n\u003Cli\u003ELack of water holds back hydropower operation during drought seasons\u003C/li\u003E\n\u003Cli\u003EWind-still weather holds back wind power operations\u003C/li\u003E\n\u003Cli\u003ELess hours of sunshine holds back solar power operations\u003C/li\u003E\n\u003C/ul\u003E\n\u003C/li\u003E\n\u003Cli\u003EStructurally insufficient production of electricity on all sources to meet the high power demand\u003C/li\u003E\n\u003Cli\u003EPeak in demand due to heatwaves\u003C/li\u003E\n\u003C/ul\u003E\n\u003Cp\u003EEskom goes on to say that they were forced to use emergency generation reserves this week as a result of under-performance at its Duvha, Kusile and Tutuka power stations, as well as delays in returning other units to service. The result is the significant depletion of the emergency reserves.\u003C/p\u003E\n\u003Cp\u003E\u003Cstrong\u003E\u003Cu\u003EIt\u2019s time to consider back-up power solutions!\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp\u003EIt is believed that Eskom is not delivering against plans for the expansion of the Country\u2019s infrastructure in order to keep up with our ever-increasing demand for power. The result \u2013 continued power interruptions into the foreseeable future.\u003C/p\u003E\n\u003Cp\u003EHow do we end our load-shedding predicament once and for all? Hmmm, Eskomplicated\u2026 \u003Ca href=\u0022https://www.magnetgroup.co.za/solutions-solar/index.php\u0022\u003E\u003Cstrong\u003EBut it doesn\u2019t have to be!\u003C/strong\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp\u003EThe Utility has appealed to the public to use electricity sparingly while the power grid remains unstable. We\u2019re appealing to YOU to consider back-up power.\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Back-up Power Enquiry\u0022\u003E\u003Cstrong\u003ECHAT\u003C/strong\u003E\u003C/a\u003E to us for a comprehensive range of back-up power solutions to meet your specific requirements\u2026\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Back-up Power Catalogue\u0022\u003E\u003Cstrong\u003EREGISTER\u003C/strong\u003E\u003C/a\u003E your interest in our Back-Up Power Catalogue now!\u003C/p\u003E\n", "created": "Mar 2021", "terms": "Back-Up Power, Education" }, { "title": "LEARN | Do you know the energy output of your solar panels? ", "nid": "473", "body": "\u003Cp class=\u0022text-align-justify\u0022\u003EThis is an excellent question. If you have a solar system, you would definitely want to know your return on the investment. In this quick article, we will share with you the tools needed to calculate the amount of power your panels output. We will also mention some of the criteria that may affect solar panel efficiency.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EWhat is the Standard Test Condition Rating?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EWhen choosing a solar panel, you would have referred to the Standard Test Condition (STC) rating to ensure the panel can generate the required amount of energy. The STC rating is indicated by a number listed on the back of the panel. This number advises the amount of power that particular panel will generate under ideal conditions. These ideal conditions of the testing environment include carefully controlled temperature and light.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EExactly 1,000 watts per square meter of solar light is shined on the solar panel during testing. The STC rating\u2019s unit of measurement is the watt or kilowatt. Wattage is calculated by multiplying the solar panel output voltage times the amperes (amps).\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EWhat factors impact solar panel output?\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe solar panel output depends on multiple factors, such as the solar panel\u2019s size, efficiency, and cell type.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E1. Solar panel size\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe average-sized solar panels found on the market today consist of either 60 or 72 photovoltaic (PV) cells. Typically, because larger solar panels offer a greater surface area to absorb sunlight, they result in higher solar panel power output. On average, 60 PV cell solar panels have a power output of 270 watts to 300 watts and 72 PV cell panels garner between 350 watts and 400 watts of power in standard test conditions.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E2. Efficiency\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003ESolar panels come with efficiency ratings. These ratings measure the amount of sunlight each solar panel captures. Solar panels with a 20% efficiency can convert 20% of the sunlight that shines on the face of that panel. Higher efficiency panels cost more than those with lower efficiency ratings.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E3. Solar panel cell type\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe solar panel cell type also affects the power output of a solar panel. Current solar panels are made with silicon solar cells. The most common types are monocrystalline and polycrystalline solar cells which have similar solar panel power output.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003EWhat factors impact solar panel efficiency? \u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EFinding ways to minimize efficiency-loss enables your panels to generate energy optimally. There are a few factors that contribute to panel efficiency:\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E1. Maintenance\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EHow often do you clean your panels? Debris or dust build-up on panels causes them to be less efficient. Wiping them down with a soft cloth a few times a year will give them the best opportunity to operate at their optimum.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E2. Orientation\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe direction your panels face also influences your solar system\u2019s efficiency. Face your panels towards the Equator to maximize your solar panel output. The tilt of your panels also impacts panel efficiency. Set the tilt of your panels equal to your latitude.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E3. Degradation rate\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EEach year solar panels lose approximately 0.5% to 1% of their rated output. This happens to all solar panels regardless of their type, but the exact percentage varies depending on the panel. Consult the panel manufacturer\u2019s warranty for more information on degradation.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E4. Shading\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EShade blocks the sunlight your solar panels are meant to absorb and reduces your system\u2019s energy production. Ideally, install your solar power panels in a location that receives full sunlight all year long.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003E\u003Cu\u003ECalculating solar panel output\u003C/u\u003E\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EAfter considering factors that can impact solar panel output and efficiency, you can then figure out how much power your panels are generating on a daily and monthly basis.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003ESimply follow this calculation:\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003E\u003Cstrong\u003ESolar Panel Output = STC Rating (watts) x Peak Sun Hours in a Day x 75% (Daily watt hours)\u003C/strong\u003E\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EThe daily solar panel output is equal to the panel\u2019s STC rating multiplied by the peak hours of sun your panel gets in a day, multiplied by 75%. Your total is the amount of watt hours that panel produces in a day.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EWhy is 75% in the equation? That\u2019s to adjust for the factors we discussed previously that affect the solar panel output.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EOnce you know the panel\u2019s daily output, you can then multiply this number by the number of days in the month and you\u2019ll have your monthly watt hours.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EYou may be more familiar with kilowatt hours. To convert watt hours to kilowatt hours (kWh) simply divide your watt hours by 1,000.\u003C/p\u003E\n\u003Cp class=\u0022text-align-justify\u0022\u003EConsidering a solar installation for your facility? \u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Solar Enquiry\u0022\u003E\u003Cstrong\u003ECHAT\u003C/strong\u003E\u003C/a\u003E to us!\u003C/p\u003E\n\u003Cp\u003E\u003Ca href=\u0022mailto:hello@magnetgroup.co.za?subject=Solar Enquiry\u0022\u003E\u003Cimg alt=\u0022maintenance of solar panels\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u0022f0cfc162-c068-4461-884e-68479a5feb70\u0022 src=\u0022/cms/drupal8-magnetgroup/sites/default/files/inline-images/PHOTO-2020-08-13-14-30-28.jpg\u0022 class=\u0022align-center\u0022 /\u003E\u003C/a\u003E\u003C/p\u003E\n\u003Cp\u003E\u00A0\u003C/p\u003E\n", "created": "Mar 2021", "terms": "Solar, Education" } ]