Determine if Uninterruptible Power Supply UPS is Maintainable

Electronics, Instrumentation & Electrical Database

Determine if Uninterruptible Power Supply UPS is Maintainable

Continued from:

• Determine if the availability of the selected UPS is acceptable.
  • of Selecting and designing a Uninterruptible Power Supply UPS

Determine if the selected Uninterruptible Power Supply UPS is maintainable: Maintenance determines much of the operating cost of an UPS. Done correctly, maintenance can ensure that the UPS stays reliable. Poorly done, maintenance can compromise reliability and safety. A system may be inherently maintainable (i.e., good access, good diagnostics, etc.), but other factors can determine whether or not the system can be maintained. These factors include availability of trained personnel, availability of spares and parts, and location of repair facilities for removed components. Availability of personnel is a function of the total number of maintenance personnel, the hours of facility operation (dictates the number of shifts during which maintenance personnel may be required), and training schedules. Availability of spares (to replace removed components) and parts (to repair in-place or removed components) depends on the total number initially procured. Replacement and repair then depends on the rate spares and parts are purchased and the rate at which the spares and parts become obsolete. Location of repair facilities is important because if they are located a significant distance from the UPS, transportation may increase the time (and the cost) to restore the Uninterruptible Power Supply UPS to operation. In many cases, the facility manager may choose to do only that maintenance performed directly on the UPS (i.e., in-place repair and removal and replacement) with internal resources. All other maintenance (i.e., repair of removed components) would be done by the Uninterruptible Power Supply UPS manufacturer or a third party. Alternatively, the manager may contract out all of the maintenance. This decision should be made primarily on the basis of cost and availability. The cost of hiring and training personnel should be compared to that of contracting out all or some of the maintenance. The expected number of repairs should be considered. A study of high failure rate components and the stock levels needed to minimize down time is also important. Another party might be able to maintain the required stock levels at a lower cost and might be able to make repairs in a shorter time. On the other hand, many contractors require time (typically 24 hours) to respond to a problem. This additional time may result in large losses of revenue. Even if internal repair is more expensive, the added cost may be
more than offset by the savings in revenue.

Continue Determine if the selected Uninterruptible Power Supply UPS is affordable.

References: “Joint Departments of the Army, Uninterruptible Power Supply System Selection, Installation, and Maintenance for Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities, 31 May 2002.”