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UPS maintenance

The reliability of many backup power systems is questionable as a result of a widespread failure to inspect and maintain equipment on a regular basis. After installation, uninterruptable power supplies (UPSs) are typically left unattended.

“The problem with backup-power is that most users install a backup system and then simply leave it, year after year,” says Jonathan Palmer, MD of backup-power specialists PowerMan. “A UPS is like insurance policy against power failures, spikes, and surges. In order to get effective protection you need to understand that a UPS has certain serviceable components that need to be checked on a regular basis.”

Palmer advocates the following basic maintenance procedures:

1. Mains failure test and battery check

The battery is the most important part of a UPS. When mains power is present, the charger has enough power to charge the batteries and run the load. However, once the mains fail, you need to know that there is enough capacitance in the batteries to run your computers for the specified time. You should ensure this by doing a mains-failure test once a month.

Start the test by turning off the mains power. Run off backup power and time the runtime. After 25% of the required runtime has elapsed, turn the mains power on again.

If your UPS has a battery capacity meter, you can be more certain of where you stand. The meters may be gauges on the front of the UPS or software that communicates with the UPS via a USB or communications port cable. Check the battery levels. If they are at 60% or higher, your system is okay. If they are lower than 60%, call your supplier.

If your UPS does not have a battery meter, the runtime will remain unknown but you know it has at least 25% of rated capacity.

In addition, you should confirm with the UPS manufacturer the runtime of the batteries of the UPS. If your runtime drops below 50% of the manufacturer’s specified time, it is advisable to replace the batteries.

Says Palmer, “Once batteries reach that level it is our experience that they will deteriorate very quickly. Usually, after three to six months they are depleted.”

2. Load check

Typically a user will call in a power company to provide backup-power. The company assesses the client’s needs and installs a backup system to fit. Over time, the client simply plugs more and more devices into the system until it is no longer able to cope with the load. You should avoid this by checking the load level from time to time. Make sure you have not exceeded the system’s power capabilities.

3. Fan check

Check that the fans are running and are not obstructed.

4. Annual service

Once a year, get a technician to service the unit. The technician should:

* Do a full battery check, testing the individual batteries in the string, and the bank of batteries as a whole.

* Check filters.

* Check all connections. A UPS can run at relatively high temperatures; therefore it is necessary to check the connections on the machine as it is possible that the connections can loosen from repeated heating and cooling.

* Take accurate load level readings. Although the UPS does give a load level reading, this should be confirmed periodically using an amp meter.

* Clean dust out of the unit.

* Check that the fans are operating efficiently.

For more information contact PowerMan, +27 (0)11 794 3886, www.powerman.co.za

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