1 00:00:00,000 --> 00:00:01,770 In this lesson, we're going to discuss 2 00:00:01,770 --> 00:00:03,750 power distribution systems. 3 00:00:03,750 --> 00:00:05,670 Power distribution systems are crucial 4 00:00:05,670 --> 00:00:06,750 for ensuring consistent 5 00:00:06,750 --> 00:00:09,690 and reliable power delivery for our networking equipment, 6 00:00:09,690 --> 00:00:11,760 infrastructure, and environments. 7 00:00:11,760 --> 00:00:14,670 Power distribution systems encompass several key items 8 00:00:14,670 --> 00:00:16,491 that you need to understand to properly manage 9 00:00:16,491 --> 00:00:19,160 and distribute electrical power within your data centers 10 00:00:19,160 --> 00:00:21,000 and network infrastructures, 11 00:00:21,000 --> 00:00:23,120 including an uninterruptible power supply, 12 00:00:23,120 --> 00:00:25,700 a power distribution unit, a generator, 13 00:00:25,700 --> 00:00:28,170 managing your power loads, and understanding 14 00:00:28,170 --> 00:00:30,030 your voltage considerations. 15 00:00:30,030 --> 00:00:33,750 First, let's talk about an uninterruptible power supply. 16 00:00:33,750 --> 00:00:37,050 An uninterruptible power supply, also known as a UPS 17 00:00:37,050 --> 00:00:38,987 or an UPS, is an electrical apparatus 18 00:00:38,987 --> 00:00:40,770 that provides emergency power 19 00:00:40,770 --> 00:00:44,537 to a load when the input power source or main power fails. 20 00:00:44,537 --> 00:00:47,250 Most people think of these as battery backups, 21 00:00:47,250 --> 00:00:48,240 but in our data centers 22 00:00:48,240 --> 00:00:50,910 and telecommunication closets, we usually use devices 23 00:00:50,910 --> 00:00:53,027 that contain more than just a battery backup. 24 00:00:53,027 --> 00:00:55,650 For our purposes, we're usually going to use 25 00:00:55,650 --> 00:00:57,450 an uninterruptible power supply. 26 00:00:57,450 --> 00:00:58,857 It's going to also provide line conditioning 27 00:00:58,857 --> 00:01:02,370 and help protect us from surges and spikes in power. 28 00:01:02,370 --> 00:01:05,069 The goal in using an UPS is to provide us with clean 29 00:01:05,069 --> 00:01:06,456 and reliable power. 30 00:01:06,456 --> 00:01:08,947 Now, an UPS is great for short duration power outages 31 00:01:08,947 --> 00:01:11,097 because they can usually last around 15 32 00:01:11,097 --> 00:01:13,980 to 30 minutes depending on the amount of electrical load 33 00:01:13,980 --> 00:01:15,360 that you're making them support 34 00:01:15,360 --> 00:01:18,120 because they are limited to a relatively short battery life 35 00:01:18,120 --> 00:01:20,190 inside of these UPS devices. 36 00:01:20,190 --> 00:01:22,200 Now the good news is that batteries are getting better 37 00:01:22,200 --> 00:01:23,660 and better every day, and their lives 38 00:01:23,660 --> 00:01:27,000 are getting longer and longer in our newer units. 39 00:01:27,000 --> 00:01:29,280 Generally, most data centers are going to place 40 00:01:29,280 --> 00:01:31,532 a single UPS unit at the bottom of each rack, 41 00:01:31,532 --> 00:01:34,161 and that way they can provide emergency power to any systems 42 00:01:34,161 --> 00:01:37,860 or networking equipment being hosted within that rack. 43 00:01:37,860 --> 00:01:39,900 Some larger data centers have also begun 44 00:01:39,900 --> 00:01:42,810 using larger UP systems that can support multiple racks 45 00:01:42,810 --> 00:01:44,846 at once or even the entire data center 46 00:01:44,846 --> 00:01:47,340 if that data center has a whole room 47 00:01:47,340 --> 00:01:49,140 battery backup system installed. 48 00:01:49,140 --> 00:01:51,159 But remember, these are very expensive, 49 00:01:51,159 --> 00:01:54,030 and you're going to find that they're less common in most small 50 00:01:54,030 --> 00:01:56,880 and medium-sized office environments due to the large cost 51 00:01:56,880 --> 00:01:58,620 of installing these units. 52 00:01:58,620 --> 00:02:01,530 Second, we have power distribution units. 53 00:02:01,530 --> 00:02:04,710 Now, a power distribution unit, also known as a PDU, 54 00:02:04,710 --> 00:02:07,019 is a specialized device for distributing electric power 55 00:02:07,019 --> 00:02:10,440 to various network components and computing equipment. 56 00:02:10,440 --> 00:02:12,187 These are essentially advanced power strips 57 00:02:12,187 --> 00:02:14,080 that are often equipped with power monitoring, 58 00:02:14,080 --> 00:02:16,710 control features, and other things that allow 59 00:02:16,710 --> 00:02:17,940 for the efficient distribution 60 00:02:17,940 --> 00:02:20,299 and management of power across multiple devices 61 00:02:20,299 --> 00:02:22,470 and multiple racks. 62 00:02:22,470 --> 00:02:25,740 A PDU can either be rack mounted in a single rack enclosure 63 00:02:25,740 --> 00:02:28,920 in a smaller organization, but in larger data centers. 64 00:02:28,920 --> 00:02:31,040 You may also see these as large cabinets 65 00:02:31,040 --> 00:02:34,410 where there's one PDU installed for each row of servers 66 00:02:34,410 --> 00:02:36,060 or networking racks. 67 00:02:36,060 --> 00:02:38,010 These power distribution units are designed 68 00:02:38,010 --> 00:02:40,280 to provide power protection from surges, spikes, 69 00:02:40,280 --> 00:02:42,270 and under voltage events, 70 00:02:42,270 --> 00:02:44,610 but they're not designed to provide full protection 71 00:02:44,610 --> 00:02:47,730 against a complete power loss like an UPS mite. 72 00:02:47,730 --> 00:02:50,190 Generally, A PDU is going to be combined with an UPS 73 00:02:50,190 --> 00:02:52,260 or a backup generator to ride power 74 00:02:52,260 --> 00:02:54,311 during a complete power failure event. 75 00:02:54,311 --> 00:02:56,910 This brings us to our third thing we need to talk about, 76 00:02:56,910 --> 00:02:58,350 which is generators. 77 00:02:58,350 --> 00:03:00,840 Now, large generators are usually installed outside 78 00:03:00,840 --> 00:03:03,461 of a data center in order to provide longer term power 79 00:03:03,461 --> 00:03:06,090 during a power outage in your region. 80 00:03:06,090 --> 00:03:08,872 These generators can be either powered by diesel, gasoline, 81 00:03:08,872 --> 00:03:12,060 or propane depending on which one you buy. 82 00:03:12,060 --> 00:03:13,411 For example, at my office, 83 00:03:13,411 --> 00:03:16,398 we have an older 20,000 kilowatt diesel generator 84 00:03:16,398 --> 00:03:17,880 that's used to provide power 85 00:03:17,880 --> 00:03:20,580 to our offices in case of a power outage. 86 00:03:20,580 --> 00:03:22,530 Now, the challenge with using a generator though 87 00:03:22,530 --> 00:03:24,540 is that it takes a little bit of time to start it up 88 00:03:24,540 --> 00:03:25,377 and get it up to speed 89 00:03:25,377 --> 00:03:28,590 before it's ready to provide power to your data center. 90 00:03:28,590 --> 00:03:30,480 For this reason, they're usually going to be paired 91 00:03:30,480 --> 00:03:32,580 with a battery backup or an UPS unit 92 00:03:32,580 --> 00:03:33,420 then when they're being designed 93 00:03:33,420 --> 00:03:35,850 as part of your power redundancy solution. 94 00:03:35,850 --> 00:03:38,695 For example, at our office, if the power goes out right now, 95 00:03:38,695 --> 00:03:42,780 the UPS is going to carry the load for about 15 to 20 minutes. 96 00:03:42,780 --> 00:03:45,000 During that time, our generator will automatically 97 00:03:45,000 --> 00:03:47,340 be brought online, and this will usually take about 98 00:03:47,340 --> 00:03:49,050 60 to 90 seconds. 99 00:03:49,050 --> 00:03:50,372 Once that generator is fully online 100 00:03:50,372 --> 00:03:52,500 and ready to take on the load, all 101 00:03:52,500 --> 00:03:54,840 of our power will be shifted from the UPS as battery 102 00:03:54,840 --> 00:03:58,410 over to the generator using an automatic transfer switch. 103 00:03:58,410 --> 00:04:00,150 Now, once power has been restored in our area 104 00:04:00,150 --> 00:04:01,783 for at least five minutes by our power company, 105 00:04:01,783 --> 00:04:05,173 then our automatic transfer switch will shift the power back 106 00:04:05,173 --> 00:04:07,950 to the electrical grid via that UPS unit, 107 00:04:07,950 --> 00:04:10,402 and then it will issue the shutdown command to our generator 108 00:04:10,402 --> 00:04:12,293 to place it back in a standby mode 109 00:04:12,293 --> 00:04:14,220 where it's rated takeover the next time 110 00:04:14,220 --> 00:04:16,140 a power outage occurs. 111 00:04:16,140 --> 00:04:17,910 The fourth thing we want to consider is 112 00:04:17,910 --> 00:04:20,040 how we're going to manage our power loads. 113 00:04:20,040 --> 00:04:21,779 Now, managing power loads is critical 114 00:04:21,779 --> 00:04:23,220 in preventing circuit overloads 115 00:04:23,220 --> 00:04:24,960 and ensuring efficient power usage 116 00:04:24,960 --> 00:04:26,820 inside of our data centers. 117 00:04:26,820 --> 00:04:28,500 Proper load balancing will ensure 118 00:04:28,500 --> 00:04:30,570 that the power supply is evenly distributed 119 00:04:30,570 --> 00:04:33,360 and that no single circuit is under excessive load, 120 00:04:33,360 --> 00:04:36,450 which could in turn lead to outages or hardware damage. 121 00:04:36,450 --> 00:04:38,250 To support this, our data centers 122 00:04:38,250 --> 00:04:39,570 are usually going to have somebody assigned 123 00:04:39,570 --> 00:04:42,540 to carefully calculate and monitor the power loads on each 124 00:04:42,540 --> 00:04:45,023 and every one of our circuits to avoid overloading them 125 00:04:45,023 --> 00:04:47,515 and to try to optimize our power usage 126 00:04:47,515 --> 00:04:49,650 for the most efficiency. 127 00:04:49,650 --> 00:04:51,210 Now, if somebody wants to install a new piece 128 00:04:51,210 --> 00:04:53,250 of networking equipment into our data center, 129 00:04:53,250 --> 00:04:54,723 like a new appliance, a new server, 130 00:04:54,723 --> 00:04:57,750 or a new switch, that person is going to be assigned 131 00:04:57,750 --> 00:05:00,000 to calculate the impact of adding that new piece 132 00:05:00,000 --> 00:05:03,060 of equipment based on its projected power utilization. 133 00:05:03,060 --> 00:05:05,160 And then we're going to recommend which rack it needs 134 00:05:05,160 --> 00:05:07,710 to be installed in to properly balance out the loads 135 00:05:07,710 --> 00:05:09,960 across the entire data center. 136 00:05:09,960 --> 00:05:10,950 Now, fifth, we have 137 00:05:10,950 --> 00:05:13,200 to think about our voltage considerations. 138 00:05:13,200 --> 00:05:15,540 Voltage refers to the electric potential difference, 139 00:05:15,540 --> 00:05:18,450 and it's a key factor in our power distribution systems. 140 00:05:18,450 --> 00:05:21,750 Now here in the United States where I live, we use 120 volts 141 00:05:21,750 --> 00:05:23,840 as our standard voltage, but over in Europe, 142 00:05:23,840 --> 00:05:26,790 they use 230 volts as their standard. 143 00:05:26,790 --> 00:05:28,650 So if I order a piece of equipment 144 00:05:28,650 --> 00:05:31,260 from a European manufacturer located in Germany, 145 00:05:31,260 --> 00:05:32,550 I need to check if it's going to be able 146 00:05:32,550 --> 00:05:34,933 to be supported by the standard 120 volt power 147 00:05:34,933 --> 00:05:37,470 that we have here in the United States. 148 00:05:37,470 --> 00:05:40,200 Similarly, if somebody over in Europe orders a component 149 00:05:40,200 --> 00:05:42,270 from the United States, they need to verify 150 00:05:42,270 --> 00:05:46,080 that it's going to operate properly on their 230 volts systems. 151 00:05:46,080 --> 00:05:47,834 For example, if I ordered a new server 152 00:05:47,834 --> 00:05:50,034 and it came with a 230 volt power supply, 153 00:05:50,034 --> 00:05:53,040 it simply is not going to power on if I connected 154 00:05:53,040 --> 00:05:56,970 to 120 volt electrical outlet in my US-based data center. 155 00:05:56,970 --> 00:05:58,380 Now, while this is unfortunate, 156 00:05:58,380 --> 00:06:00,503 it's actually not going to hurt that piece of equipment, 157 00:06:00,503 --> 00:06:02,783 and instead, I can simply purchase a transformer 158 00:06:02,783 --> 00:06:05,987 to convert my lower voltage 120 volt power source 159 00:06:05,987 --> 00:06:09,030 into a 230 volt power source that that piece 160 00:06:09,030 --> 00:06:11,040 of equipment can then utilize. 161 00:06:11,040 --> 00:06:13,380 On the other hand, if somebody in Europe doesn't think 162 00:06:13,380 --> 00:06:15,630 to check the power requirements on a new piece of hardware 163 00:06:15,630 --> 00:06:16,667 that they bought from the United States, 164 00:06:16,667 --> 00:06:18,339 and they plug that piece of equipment in 165 00:06:18,339 --> 00:06:21,270 and they expect it's going to get 120 volts like it does here 166 00:06:21,270 --> 00:06:24,000 in the United States, well, guess what's going to happen? 167 00:06:24,000 --> 00:06:27,030 That piece of equipment is going to be damaged badly 168 00:06:27,030 --> 00:06:29,070 because it's going to be receiving 230 volts 169 00:06:29,070 --> 00:06:31,800 from the European electrical socket in that data center 170 00:06:31,800 --> 00:06:34,290 instead of the 120 volts it's expecting. 171 00:06:34,290 --> 00:06:35,820 This can actually destroy the device, 172 00:06:35,820 --> 00:06:37,501 or it can even cause it to catch fire 173 00:06:37,501 --> 00:06:40,350 due to the voltage mismatch that's occurring. 174 00:06:40,350 --> 00:06:43,080 Now, luckily, most devices these days are considered 175 00:06:43,080 --> 00:06:45,210 to be dual voltage and they can be configured 176 00:06:45,210 --> 00:06:48,630 to operate either at 120 volts or 230 volts, 177 00:06:48,630 --> 00:06:49,830 or they'll automatically switch 178 00:06:49,830 --> 00:06:52,530 between the two based on what you have there. 179 00:06:52,530 --> 00:06:54,153 Now, this all depends on the equipment you're using, 180 00:06:54,153 --> 00:06:55,565 but it is something you need to consider 181 00:06:55,565 --> 00:06:57,821 to ensure your network equipment operates optimally 182 00:06:57,821 --> 00:06:59,965 and maintains this longevity. 183 00:06:59,965 --> 00:07:02,344 So remember, when you're designing your data centers, 184 00:07:02,344 --> 00:07:04,194 you need to consider how you're going to distribute 185 00:07:04,194 --> 00:07:06,834 and maintain power throughout the entire data center. 186 00:07:06,834 --> 00:07:09,570 You may opt to install a UPS in each of your racks 187 00:07:09,570 --> 00:07:12,064 to provide power in case of a short-term power loss, 188 00:07:12,064 --> 00:07:15,000 but you're probably also going to want to install a PDU 189 00:07:15,000 --> 00:07:17,550 and a backup generator as well, so you can continue 190 00:07:17,550 --> 00:07:19,890 to operate for the long-term regardless of whether 191 00:07:19,890 --> 00:07:22,560 or not there's a power outage occurring or not. 192 00:07:22,560 --> 00:07:24,514 Also, don't forget to consider the power loads 193 00:07:24,514 --> 00:07:26,670 that you're going to be installing with any new piece 194 00:07:26,670 --> 00:07:28,532 of equipment, and you should always consider the voltage 195 00:07:28,532 --> 00:07:31,200 required by your equipment before you install it 196 00:07:31,200 --> 00:07:33,700 and connect it to your data center's power source.