The following is a brief outline of a presentation made to the Building Operator Association on February 11, 1997.

Pump Oversizing
Pump oversizing is a very common problem. The pump should be tested by taking suction and discharge pressures and plotting this on the pump curve. If a pump is oversized, power consumption can be reduced by as much as 75% depending on the pump and the operating point. In one case the horsepower requirement of the pumps were reduced from 300 horsepower to 100 horsepower, while still maintaining the desired system flow.

Parallel Pumping
Quite often the building operator is unaware if his pumps are designed for parallel or 100% standby operation. By pressure testing the pumps and checking the boiler flow requirements, the proper pump operation can be determined. Operating one pump when two are required often causes the pump to cavitate. Over time this will damage the pump impeller, it may also cause problems due to insufficient flow.

Lubrication
Proper Fan and Motor lubrication was discussed, charts showing the re-greasing intervals for motor and fan bearings were displayed. Mixing greases shortens bearing life. Motor and bearing manufacturers use either lithium or polyurea based grease and the two types should not be mixed. Care should be taken when selecting the type of grease that you are going to use. Once you decide the type (polyurea or lithium based) that best suits your needs, you should not change types. You should specify the type of grease you use when having your fans and motors repaired, the service company could then select the bearing make that is compatible.