Power Distribution Units -PDUs- are one of those aspects of network design which are often overlooked... until there are power problems, that is. The truth is that good rack PDU choices are absolutely vital to proper network performance and uptime, even if they aren't as "sexy" as investing in the latest high-tech switch or routers. Without proper power distribution, even the most cutting-edge network is useless.
So today, we wanted to take a look at the basic options in rack PDU units available, and what sort of businesses they might be good for.
The Seven Major Types Of Rack PDUs And Their Advantages
1 - "Basic" PDUs
This is the standard no-frills budget option. It converts one or more high-power outlets to several lower-power options, and that's about it. These are a good fit for startups and those implementing their first rack-based network, but it's virtually inevitable an organization will outgrow it. Buying a better model from the start is often a good idea unless budgets are truly tight.
2 - Metered PDUs
Metered PDUs generally feature digital displays on their face plates, which provide basic usage information such as loads and voltage. They also can self-monitor for impending overloads, potentially preventing burnouts or other electrical problems. This also makes it easier to attach new equipment safely, without risking overload. These are probably the baseline for a serious rack PDU implementation.
3 - Monitored PDUs
The main difference between monitored and metered PDUs is that monitored PDUs are network aware, and accessible remotely. Configuration options are limited, but admins can at least see what's going on without being at the rack's location.
4 - Switched PDUs
This is the price point where a rack PDU starts becoming a serious piece of hardware. Switched PDUs can be operated and configured remotely, including live adjustment of power levels or shutting off unnecessary equipment. (such as overnight) They can also generally create detailed reports on usage and power loads, useful for fine-tuning your operations or reducing unnecessary energy consumption.
5 - Hot-Swap PDUs
The main feature in hot-swap units is that they allow for multiple power inputs at once, such as from both a UPS and a standard wall socket. This then allows UPS units to be swapped out without having to take the network offline to do so, as well as adding redundancy. This is an excellent option for those whose networks must maintain uptime.
6 - Automatic Transfer Switch PDUs
Going a step beyond hot-swaps, ATS PDUs have two or more power inputs, and can automatically switch between them in cases of power failure or other emergencies. They work best with multiple UPS systems, which are then connected to separate power supplies for maximum redundancy. Such setups may be expensive to implement, but provide superior reliability.
7 - Dual-Circuit PDUs
Finally, at the top end are dual-circuit PDUs options. These feature multiple inputs and multiple outputs, specifically for high-end network hardware which features onboard redundant power supplies. A single dual-circuit PDU can effectively replace two separate high-voltage PDUs, reducing complexity and management overhead. Again, for best effect, they should receive power from separate UPS, generators, or other power sources.
And, of course, features will vary between models. Knowing which features you need will allow you to quickly pick the best PDU for the job.
In any case, pre-planning is the most important element of all when selecting a PDU. Don't purchase based only on your needs today; also think about your upgrade path for at least a couple years in the future. If you need more advice, please don't hesitate to contact Hummingbird Networks for a free consultation!
