Concerns with rising energy costs are driving operators of data centers and other networking installations to rethink how the facilities are structured, including changing expectations for how intelligent power distribution units (iPDUs) can contribute to a greener, more reliable, and lower-cost operations, all of which contribute to improved network availability. Plus, a growing variety of data center types require different approaches when specifying and integrating iPDUs, ranging from large data centers that support cloud computing to much smaller data centers on the edge dispersed in factories, warehouses, etc., other facilities. Large data centers are being operated with iPDUs in hot aisles with temperatures of 60°C to reduce cooling needs and energy consumption. In comparison, edge datacenters operate at maximum temperatures of 40°C that conform with the facility’s environment where they are located.
The specifications and operating characteristics of iPDUs need to be matched to the environment where they are deployed. There is a growing expectation that iPDUs will support remote energy monitoring and controls to optimize availability in all cases.
This article compares and contrasts the operating environments and expectations for iPDUs in cloud versus edge environments, including both hardware and software, along with deployment recommendations; it then presents iPDUs suited for cloud and edge data centers from Panduit and Orion Fans.
Three of the features of cloud and edge environments that impact iPDU selection are the differences in thermal environments, differences in networking communications architectures, and differences in equipment densities. Probably the most challenging difference between cloud and edge environments is the expectation for operation at up to 40°C for most edge installations compared with 60°C operation in cloud data centers (Figure 1). In cloud environments, hot and cold aisles minimize cooling needs and reduce energy costs, a major operational cost in large data centers. The iPDUs are typically found in the hot aisle and must be rated for 60°C.
Figure 1: The iPDUs in cloud data centers need to operate at 60°C so that they can be installed in hot aisles. (Image source: Panduit)
In addition, when running hot and cold aisles, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) requires three temperature sensors and one humidity sensor (called ‘3T + H’) on the front of the cabinet in the cold aisle, and just a temperature sensor in the rear of the cabinet on the hot aisle. As a result, iPDUs that support multiple sensor inputs can eliminate the need for an intermediary 1RU appliance for the sensors and be an important consideration in cloud datacenters.
While both edge and cloud installations value high availability, it’s relatively more important in cloud environments. The controller module on iPDUs needs to be hot-swappable for units installed in cloud datacenters. Being able to hot-swap the controller module minimizes downtime, an essential consideration in the cloud. In addition, Gigabit (Gb) Ethernet is more widely adopted in the cloud than other connectivity speeds, and iPDUs in the cloud benefit from supporting Gb Ethernet connectivity that is not as highly valued in edge installations. Additionally, cloud installations generally require iPDUs that support higher levels of security and more complex power monitoring and management software.
Higher density racks are found in cloud datacenters compared with the edge, making power density an important factor in iPDU selection for cloud facilities. IPDUs in cloud data centers benefit from higher outlet densities but must still provide a high level of intelligent power control and monitoring to support higher power densities.
In both cloud and edge installations, accidental power cord disconnects are a leading cause of equipment downtime. The most common cause of accidental disconnects in iPDUs is the effect of vibration and gravity over time pulling on the power cables; it’s not ‘user error’. Designing iPDUs that minimize the effect of vibration and gravity on power cables, thereby minimizing accidental disconnects, can be important in edge installations and is required in cloud facilities.
iPDUs rated for 60°C at full load
Datacenter engineers can turn to Panduit’s G5 intelligent PDUs (Gen 5 iPDUs) to address cloud installations’ power distribution, availability, security, and monitoring needs. Gen 5 iPDUs have an operating temperature of 60°C at full load. They also have sensor inputs to support the ASHRAE requirement for 3T + H on the cold aisle and a temperature sensor on the hot aisle without an intermediary 1RU appliance. Digital self-identifying sensors can be plugged directly into the iPDU, speeding deployment.
The intelligent network controller (iNC) in the Gen 5 iPDUs is hot-swappable to support maximum uptime (Figure 4). It includes a high visibility OLED display, reset/factory default control, menu selector buttons, a status LED, a USB connector for firmware and configuration updates and/or optional automatic rack light connection, 1Gb Ethernet port for network connections, PDU out and PDU in/serial ports for daisy chaining multiple iNCs, and two sensor ports that can each connect to up to 4 sensors, for a total of 8 sensors, using the optional sensor expansion port.
Figure 2: The iNC in the Gen 5 iPDUs is hot-swappable to support maximum uptime and supports a wide range of monitoring and control functions. (Image source: Panduit)
Up to four iPDUs can be daisy-chained and connected to two different secure network connections for:
- Monitoring power usage and tracking data on a facilities network and;
- Managing and monitoring up to four rack iPDU’s, using only a single IP address (Figure 5).
Each iPDU in the daisy chain can be connected to up to eight sensors, for a total of 32 sensors over a single connection. In addition, a redundant network access configuration is available using two iPDUs.
Figure 3: Up to 4 Gen 5 iPDUs can be daisy-chained together through a single IP address. (Image source: Panduit)
The need in large data centers is to monitor and identify inefficiencies to improve operational efficiencies, reduce costs and minimize the environmental footprint. Gen 5 iPDUs support comprehensive, accurate energy measurement software to efficiently use power resources, make informed capacity planning decisions, improve uptime and measure power usage effectiveness (PUE). These iPDUs offer the necessary energy metering, monitoring, and controls to support continual improvements in energy usage, including:
- PDU level energy metering and monitoring
- Watt-hour energy metering (kWh)
- Power measurements (W)
- Input Phase level power measurements including V, A, VA, kWh, and power factor (pf)
- Circuit breaker level current measurements
- Billing-grade metering capabilities
- Integrated memory to record/view/report historical data
- Customizable alarm thresholds & notifications
- Outlet level controls
- Remote power on and off by individual outlet
- User-defined power-on time delay to sequence equipment and avoid inrush current overloads
- User assignable roles and access security levels
- Outlet level energy metering
- Watt-hour energy metering (kWh)
- Power measurements including V, A, VA, W, and pf
- Data for Green Grid Level 3 PUE calculations
The Gen 5 iPDUs provide high power densities, feature up to 48 outlets, and come standard with a 10-foot (three-meter) input power cord. They are available with a range of mounting configurations, including vertically (0U) or horizontally (1U or 2U). For example, model P36D08M is rated for 30 A per phase, is in a 0U FULL form factor, has an L15-30P input plug, 3 circuit breakers, can handle 8.6 kW, and has 36 outlets ( 30 C13 and 6 C19).
Designers using Gen 5 iPDUs can choose between two different solutions to the problem of accidental disconnects. Standard C13 and C19 outlets have an integrated recessed slot next to them designed to accept a non-conductive cable tie, effectively eliminating the effects of vibration and gravity. While these outlets are less expensive, there’s a labor cost incurred in using the cable tie, and it doesn’t secure the power cord on the equipment side. Gen 5 iPDUs are available with locking cords that click securely into place for a more complete solution. Furthermore, the equipment end has a universal locking mechanism that locks to the IT equipment, providing permanent cable retention on both ends. Depending on the installation needs, specifiers can use Gen 5 iPDUs that combine outlets with cable tie slots and locking outlets (Figure 4). In addition, cloud data centers have large numbers of power cords feeding the A and B sides in the back of the cabinet, which can complicate cable management. Gen 5 PDUs offer colored cable ties, color marking straps, and color power cords (both locking and non-locking) to simplify the identification and management of A and B side cables.
Figure 4: Gen 5 iPDUs offer a choice of cable ties or locking outlets to address concerns with accidental disconnects. (Image source: Panduit)
The Panduit Smart Zone G5 optional security handle can be used with Gen 5 iPDU to provide access control for up to 200 users. The handle includes a status LED that provides the security state of the handle, and a beacon LED indicating the health of the cabinet. It also features an integrated humidity sensor and dedicated temperature and door alarm sensors to simplify sensor installation and meet the ASHRAE standards (Figure 5). The G5 security handle includes field replacement lock tumblers and keys and four ways to control access to the cabinet:
- Dual-frequency card readers can be used with either low-frequency or high-frequency cards.
- Access can be remotely controlled through the web interface contained in the Gen 5 iPDU.
- The model ACF06 includes an optional keypad that allows cabinet access through a secure pin code.
- The model ACF06 can implement dual authentication when both a card swipe and keypad are required.
Figure 5: The optional Smart Zone G5 security handle has an integrated humidity sensor and status LEDs and can be configured with or without an integrated keypad for access control. (Image source: Panduit)
iPDUs for Edge installations
For data centers on the edge and other applications that can use iPDUs rated for 40°C maximum operation, Orion Fans offers the Smart Switched PDU series that features outlets that can be remotely started sequentially, controlled, and monitored. Smart Switched PDUs individually monitor each outlet, and in the event that a user-defined threshold is exceeded, sends a warning via email, trap, or audible alarm. Other features include:
- Outlet level power control and monitoring for rack-mounted equipment
- Operation from 0 to 40°C
- Power monitoring by meter, web, or simple network managing protocol (SNMP)
- http, https, SNMP, DHCP, and UDP communication protocols
- Digital, true RMS current meter on the PDU
- Bundled software provides control and analytics to improve energy efficiency, reduce operating costs, and minimize downtime
For example, the model OSP-V-16-23-16-N1 includes 14 IEC320 C13 and 2 IEC320 C19 outlets, an IEC320 C20 Inlet, and an enclosed IEC320 C19 to C20 3 meter long power cord, and a 16 A circuit breaker. Alternatively, the OSP-H-16-23-08-N1 has 8 IEC320 C13 outlets, an IEC320 C20 Inlet, an enclosed IEC320 C19 to C20 3 meter long power cord, and a 16 A circuit breaker with a three digit 20 A current meter with a resolution of 0.1 A (Figure 7).
Figure 6: The OSP-H-16-23-08-N1 iPDU has 8 IEC320 C13 outlets and a three digit current meter with a resolution of 0.1 A. (Image source: Orion Fans)
Cloud and edge data centers have different needs for iPDUs, including different operating temperature requirements, different expectations for reliability and availability, and different needs for security, power control, and monitoring. Network engineers can select from iPDUs that suit the specific requirements of edge and cloud installations to support greener solutions with the optimal balance of cost versus performance.