Data centers use 2% of the world’s electricity. While that number may not seem like a huge number, that demand is expected to grow eightfold by 2030 – faster than any other industry sector. Much of this electricity is used to cool the facility and run the servers.
Data center power consumption.
A typical data center has an average of 500 electric motors in its HVAC system, which is a lot of motors to maintain while they cool servers and other critical equipment. For data center operators, not only is reliable performance a must, but so is managing the cost of electricity to run all those engines. Choosing the right motors will help minimize operating expenses and ensure energy costs are kept to a minimum.
Use only the energy needed
Did you know that most HVAC systems run at 80% load or less, and do so more than 99% of the time? Traditionally, dampers, valves, and other mechanical means are used to regulate the power or speed of a motor to run fans, pumps, and compressors in HVAC systems.
To reduce electricity consumption and maximize energy efficiency, operators should ensure variable frequency drives (VFDs) are integrated into motor operation, as this can save 20-60% of energy costs . VFDs help match power consumption to actual power needs, eliminating wasted energy.
However, not all motors can be operated with an inverter. Selecting an inverter motor that includes some form of motor bearing protection is also important. An ultra-premium efficient motor (IE5+) reduces energy loss by up to 40% compared to standard induction motors (NEMA Premium efficiency) that operate directly on the line (DOL).
Mitigating Well Current Issues
While using a VFD to control your motor has many benefits, it can also present some challenges. Without proper wiring and grounding techniques, shaft currents induced by VFDs will find the path of least resistance, usually through the motor bearings to ground. Damage from this electrical discharge can lead to catastrophic motor failures.
However, there are many ways to alleviate well current problems.
Data centers can’t afford any downtime; therefore, insulated bearings as well as shaft grounding devices that direct the current away from the bearing are becoming common practice when specifying motors. Insulated ceramic bearings are non-conductive and prevent shaft currents from flowing through the motor bearings all together. Since no electrical current flows through the motor bearings, there is little risk of current-induced wear.
Highly efficient components and isolated bearings provide a combination of performance and protection.
Smaller size, better efficiency
A trend in industrial engineering has been towards the use of more and smaller motors, optimized for specific tasks. Matching the power of a motor to the maximum power required for a task is already a major step towards greater energy efficiency. Large belt-driven fan applications are replaced with smaller fans in an array to improve system efficiency. While this improves overall fan efficiency performance, it introduces more complexity to the system. Multiple motor and drive configurations are an ideal configuration due to the reduced maintenance costs associated with replacing direct drive fan applications or motors and drives together.
Replacing belt-driven configurations with direct-drive systems reduces complexity and maintenance costs while increasing efficiency.
More durable means more durable
Modern high-efficiency motors, combined with variable speed drives, are designed to be flexible and reliable. Most importantly, they are extremely efficient, offering significant reductions in power consumption compared to older systems. Motors that run reliably longer do more than reduce electricity consumption and lifetime cost; they are also more durable than an engine that requires constant maintenance or needs to be replaced often. Motors designed for reliability help extend the life of the driven load and the durability of the data center.