Ken Koty, sales engineer for PDU Cables ( and former data center facilities manager for Thomsen Reuters, says:

Power outages occur; they are practically unavoidable, that’s why diesel generator backups are such an important part of the data center industry.  My data centers didn’t need our backup generators very often, but when we did, it was critical that they be ready to go at a moment’s notice.  Knowing whether or not a generator would start, run or meet our energy needs was never an issue because of the tests and inspection schedule we maintained. 

Following is a list of some of the maintenance practices we instituted with our diesel generators.  

Daily Inspections:

These are some inspection practices that either someone on my team or I would perform on our diesel generators every day. 

·         Look for oil or coolant leaks and check oil and coolant levels.

·         Check to be sure the coolant jacket heaters are working.  In colder climates, keeping your coolant heated could be the difference between a generator starting or not starting.

·         Check to make sure the battery charger is working. 

·         Look for any signs of corrosion on battery posts, if found clean them immediately. 

·         Check air intake and exhaust vents for blockage. 

Monthly Inspections:

In addition to the daily inspections, monthly test of the generators under load reassured me that everything was in working order. 

·         Before testing the generator, check the specific gravity reading on your batteries.  They should read about 1.260.  

·         Exercise generators under load for at least 30 minutes.

·         Log readings; coolant temperature, oil pressure, volts and amps. 

·         During the test, check the exhaust system to be sure no leaks are present.  

Periodic Maintenance:

Following are some periodic maintenance tips to enhance reliability and extend the life of a diesel generator. 

·         Inspect air filters and change when dirty.  The generators working environment will determine the frequency. 

·         Change oil every 250 hours of operation.  Send a sample in to be tested, this will provide insight into the generators engine condition. 

·         Replace batteries every three years.  Our practice was to use two batteries in parallel on each generator to increase reliability. 

·         Replace the glycol every three years.  It’s a good practice to have a sample of the glycol tested as well. 

·         Have the engine valves adjusted every three years.  This can help extend the life of your diesel generator. 

·         Test onsite fuel storage every six months.  Be sure your fuel supplier is providing you with artic fuel during the winter months.  I would call and make sure the fuel supplier had switched to artic fuel and then let the onsite fuel run lower than normal to make sure that there was ample room to get a large amount of the artic fuel blend into the storage tanks.  

The key to diesel generator reliability is a good maintenance program. While at Thomson Reuters we experienced tremendous growth in our data centers and with that growth, came the need for additional diesel generators.  Making sure the generators would supply power when needed was vital to our business and expected by my IT customers.