Ultimate Guide for Rack PDU

Do you have a computer network with Patch panel, Network switch, routers, UPS (uninterruptible power supply), and many more?

How do you power those devices in your network rack or server cabinet? Are you still using a power strip or extension block?

Then why not use a PDU (power distribution unit) for your devices.

What is a PDU?

 A PDU or shortcut for power distribution unit is a device that distributes power access to multiple devices on a network. It doesn’t make power but delivers it form a UPS or utility power source to many networking devices within a network rack.

What does PDU do?

PDUs are created for installation in devices racks, holding installed devices like servers, switches, routers, or cooling fans within reach of rack control.

PDUs are most generally used in data centers, network closets, VoIP telephone networks, and industries.

What is a Rack PDU?

Rack Power Distribution Units (RPDUs) are the last connection in the power chain and ensure vital power for IT loads is supplied. The RPDU is configured to disperse the power inside the data center to all forms of IT equipment.

The RPDU is capable of tracking, handling and regulating the power consumption in data center environments to multiple devices.

It can deliver vast quantities of power, which can be accessed either remotely or via the local network. RPDUs can handle higher power densities and are resistant to elevated temperatures to meet the ever-changing needs of the data center.

Many RPDUs are conveniently upgradable and operable without the need to remove power from the connected devices to avoid disrupting the basic power delivery.

What are the Importance of a Rack PDU?

1. They make your IT installation more secure.

Some suppliers of rack PDU have developed a plug retention feature that takes up no extra space and delivers maximum reliability without the drawbacks of older solutions.

     2.Maintenance and updates are streamlined.

Enables complete access to all rack mount devices. These often include hot-swappable components like meter frames, which can be mounted or exchanged without interrupting the loads ‘supply. The best rack PDUs are color-coded as an added advantage, so that maintenance technicians can see at a glance the circuit breaker regulates the socket.

    3.They provide energy monitoring.

This guarantees that users can easily identify exactly where energy is being used and ensure the fast detection of equipment that receives more resources.

    4.They help to reduce the cost of your cooling.

Older rack PDU systems cannot be able to cope and need additional cooling, but new generation PDUs may operate at up to 140 ° F continuously.

    5.They are putting you in charge of their resources.

Users can turn the power on and off to individual socket outlets remotely using switched rack PDUs. The switching can be performed manually.

    6.They make the management of your power system easier.

Nowadays, rack PDUs support mass configuration and updating that minimizes the time required to manage the power system. Changes commonly happening in today’s complex IT environments can be introduced quickly, effectively, and with minimal error risk.

    7.They help you save money on components of the network.

Network connections are required to provide access to its control and monitoring functions for all advanced rack PDUs. This system is costly and unwieldy as administrators have several IP addresses to deal with. The new rack PDUs minimizes physical infrastructure costs, where multiple PDUs can use a single port and just one IP address.

   8.They provide you details about your on-the-spot status.

Rack PDUs have mixed displays that can be rotated right on the unit to match the introduction of the installation and show key details, like alarms. This makes it possible to test the power system operates at a glimpse, which is an important benefit for the exposure which correction of failures.

   9.User friendly and flexible.

The best rack PDUs are easy to install and deliver mounting positions to choose from. They are light but durable and their aluminum frame efficiently diffuses heat and provides excellent conductivity on the ground.

Types of Rack PDU

     1. Basic Rack PDU

 With more outlets this device helps a UPS to distribute power to other devices.

Basic RPDUs ensure a secure transfer of power inside a rack or cabinet to vital IT equipment.

The Basic PDU Series includes versions in variants 1U and 0U with customizable front and/or back outlet arrangements.

The features of the series include long-lasting metal casing, horizontal/vertical mounting, switch-free design, network-grade plugs, outlets, power cord and cord keeping tray.

      2.Metered Rack PDU

 This type of PDU distributes network-grade power and can monitor load level locally with its digital current meter to avoid overloads while offers reliability.

 It allows the data center managers to instantly show metrics of power consumption from a local monitor. This is suitable to track power consumption and avoid overloads when deploying or moving equipment.

They are ideally designed for highly secure data center environments that have to keep the power supply from the local network air-gapped.

Each Metered PDU has a digital LCD meter to track the loads in real-time.

The features of the series include long- metal casing, horizontal/vertical mounting, switch- design, network- plugs and outlets, power cord and cord keeping tray.

      3. Monitored Rack PDU

A monitored PDU is like a metered PDU which distributes network-grade power and helps avoid downtime because of overloads or other power interruption.

This type is one step better with its ability to monitor a single or three-phase voltage, frequency remotely and load levels in real-time thru a built-in network connection.

Local management is easy with the digital meter display which displays output current consumption and monitoring remotely through an SNMP network interface.

    4. Switched Rack PDU

A switched RPDU is the type of PDU that allows remote management, monitors PDU’s vitals, and control of outlets and clients in a network via SNMP (Simple Network Management Protocol) or Web.

Outlets on this type of PDU can be switched on and off to remotely reboot or restart devices connected to it so we can be free with the costly service calls.

With the PDU’s built-in digital current meter you can monitor load level and avoid overloads.

To prevent unauthorized connection of devices unused outlets can be electronically locked and power plan cycling of connected devices can happen without disrupting the performance.

Switched RPDUs are suitable for data centers that need to restrict outlet power consumption to prevent both unintended overloads and remote data centers. They are particularly useful for data centers needing a fast and simple way to power cycle equipment in a large facility or, in some cases, a whole facility network.

    5. Switched Metered-by-Outlet PDU

 For advanced energy management, switched Metered-PDUs combine network power delivery with outlet level tracking and remote outlet control.

Track the power usage of single outlets over the network in real-time, or use the interactive digital display of the PDU locally. Your outlets can be turned on and off remotely for unplanned reboots, load shedding, power-cycling controls and more.

Mitigate risk with alerts of power events via email and mobile text messages. Other features of the Switched MBO PDUs include the SNMP network interface, long-lasting metal housing and a flexible horizontal/vertical mount rack configuration.

     6. Metered Auto Transfer Switch (ATS) PDU

 It can turn to secondary control when the primary power loss occurs.

An LCD screen shows amperage, voltage input and output, active consumption in kilowatts, and information about hardware and firmware. An optional SNMP card lets you track and control remotely.

Dual power input cords allow ATS PDUs to connect to a primary and secondary power source, with the primary input cable giving normal consistent output.

If the primary power source ever fails or becomes unreliable, the ATS PDU will turn to the secondary power source automatically, before the primary input is restored.

    7. Switched Auto Transfer Switch PDU

Switched Auto Transfer Switch (ATS) PDUs are designed for data centers and other electrically challenging applications, transmit unfiltered electrical pass-through to receptacles from excess sockets.

Outlets can be centrally or locally operated, either individually or collectively. The dual power cords can be placed into separate power sources.

When power reaches the lower or upper limits for the primary source, or if power fails, the PDU may turn to the secondary power source to ensure constant operation.

The LCD panel displays the current draw for connected devices, input and output voltages, levels of active power consumption (shown in kilowatts), and versions of hardware and firmware.

     8. Maintenance Bypass PDU

 Built for data centers and other locations where uptime is crucial, Maintenance Bypass PDUs allow the smooth transfer of an electrical charge from UPS to utility power for continuous operation of connected equipment while conducting repairs, replacing batteries, or installing a new UPS.

Which Type of PDU is right for me?

When data center needs and specifications change, so do the PDU efficiency options for the rack. Today, before choosing rack PDUs, there are many questions to ask which will work well for your data center application.

These are the things you need to consider and the questions you need to ask yourself to find the right PDU model for your needs.

Where will I install it?

Type of Mount – A rack PDU can be installed horizontally or vertically, depending on where you want to place it.

One option is to be mounted horizontally within the rack (taking up RU space); another option is to mount a PDU vertically on the rear or side of the enclosure (not taking up any RU space).

You’ll also see one vertically mounted PDU on the left and one on the right of a cabinet in the data center (although rack PDUs can be mounted on either side, based on preferences).

What kind of input power do I have?

Single- or 3-Phase Power – the kind of power delivery in your data center will decide if a single- or three-phase PDU is needed. The difference includes where the process is broken down in the delivery system.

Single-phase operation (requiring single-phase rack PDUs) would be necessary when it is broken down at the distribution panel. If taking all three phases to each rack, then a 3-phase PDU is required. The input power at most data centers is a 3-phase operation.

How much power does my equipment need?

Amperes and Voltage – Your power rating — the amount of sustained power a PDU can handle — determines the level of amperage you’ll need.

Why does it matter? Because, for example, if a 30A circuit consumes more than 30A of power for an extended period a PDU with a 30A fuse will blow.

In addition to various amperes, particular input voltage choices also exist for rack PDUs; 208/240V is the most common voltage output for computing equipment, with a recent trend heading towards 400V input. Confirm the voltage of your network and you will know what kind of voltage your PDU needs.

How many outlets do my devices need?

Receptacle Count/Type – The number of receptacles you need should not be strictly dependent on the number of devices to be plugged in right now – it should also consider potential growth in the rack.

• While there are personalized choices when it comes to receptacle count, choosing from a standard option usually makes the most financial sense. Since vertically mounted PDUs can be longer, they appear to give more receptacles per unit.
• The number of receptacles in a PDU rack is always balanced in each phase.  Some has  24-, 30- and 42-count receptacles – for 3-phase capacity, they are all divisible by 3.
• Determine the types of connectors used on the gadgets in your rack, too. For example, most computing gear uses C-13 or C-19 input cords, so it is necessary to decide the ratio needed in your PDU rack.

What kind of plug does my devices have?

Usually, see plugs (locking) in the NEMA model on rack PDUs. To protect electrical connections and prevent accidental disconnection, locking plugs are common.

An IEC-style plug is the other choice. The third type of plug, known as the California-style plug, is often used in North American data centers (usually used on 50A circuits). You can find PDUs with this sort of socket, too.

Please make sure that the PDU you select suits the plugs on the unit you are connecting to. Those PDUs provide a combination of plug styles for input and output.

Do I need other features of PDU?

A typical PDU has multiple devices sharing a common power source. It simplifies rack equipment management and makes a valuable addition to any IT installation.

Advanced models do much more, ranging from calculating demand to defending against downtime to enabling remote device control.

What is the difference between PDU vs UPS?

 UPS (Uninterruptible Power Supplies)

• Provide maximum defense, including a power outage, from both self-inflicted and utility-induced power quality incidents.
• Quality UPS is available in various sizes, from adequate to protect a single server to a data center of several hundred thousand square feet (in-rack to facility level).
• Power delivery from the entrance of the building to the rack is a vital component of a highly accessible data center.

PDU (Power Distribution Unit)

• A Power Distribution Unit (PDU) at the facility level distributes power to the individual racks, and a rack PDU can provide the critical load for the final delivery. Depending on the specific up-time specifications of the system, a single or double (2N) delivery scheme is used.

• Whatever kind of computer equipment you have for your plant, if you can’t supply it with reliable electricity, it will all be useless. By installing servers, switches, routers, computers, and other tools in an equipment rack, you need to make sure that you have plenty of space to plug them all in so that they don’t overwhelm the network.
• This usually leaves you with two key options: either you use a power strip, or a power distribution unit (PDU). With the right understanding of their uses helps you choose and decide which power distribution is the best for your needs.

What is the difference between PDU and a Power Strip?

It is important to know everything about power strips and PDUs when looking into your options for supplying power to your computer equipment.

The power strips are of lower voltage with limited characteristics.

PDUs have full remote monitoring and control features that are recommended when connecting to conditioned electricity and are characteristic of data centers and computer rooms designed for the purpose.

An input plug, breaker and outlet identify the PDUs and power strips power supply role and the function of metering or remote monitoring identifies the control role.

What is a Power Strip?

At some point, almost everybody had used a power strip. You just plug in one wall socket, and provide a power cord length that ends in a ‘strip’ of electrical outlets. Several different models are offering different cord lengths, different outlet numbers and much more. Some of the main choices with a power strip you’ll have include:

• Length of Cord
• Number of Outlets
• Surge Protection
• Mounting Options
• power capacity
• Outlet Type

Does a PDU have Surge Protection?

Rack surge protectors spread power to multiple devices from a single source but are not exclusively PDUs. These are equipped for use with devices that must be guarded against spikes and fluctuations in voltage but do not require battery backup. Since these devices are specifically designed to defend against over voltages, they are known to be surge protectors and not PDUs.

What is a SMART PDU?

In addition to supplying power to IT equipment within the data center, a smart PDU, also known as intelligent PDU can track, handle, and regulate power consumption across multiple devices.

The smart PDU offers remote network access to important infrastructure data for data center professionals in real-time to help improve informed decision-making to ensure optimum capacity and meet essential performance criteria.

Although, there are two main types of smart PDUs, controlled and switched, each type has several additional features that can be used to improve vital system information. Some of the main features include outlet level tracking, environmental control, user- threshold warnings and alarms and many more.

Things to consider when choosing a Smart PDU:

• Functionality
• Reliability
• Alternating Outlets
• Adaptability
• High Temperature Grade
• Locking Outlets

As computing demands continue to grow, data centers can no longer afford just high-level analysis of power delivery.

Advanced rack PDUs have the usability and functionality the data centers of today need to manage their operations, but more importantly, to meet the business ‘evolving and growing demands.

It would be smart for companies to improve their power strategy by considering the current rack environment and workload demands, followed by selecting an optimized rack PDU, and then back up the network with a virtualized management software-enabled UPS.