Page 184 - HVAC Pump Handbook

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Pump Drivers and Variable-Speed Drives

Pump Drivers and Variable-Speed Drives 181

TABLE 7.3 Nominal Full-Load Efficiency Levels Covered by EPAct
Enclosed Motors Open Motors
6-pole 4-pole 6-pole 4-pole
Motor HP 1200 rev/min 1800 rev/min 1200 rev/min 1800 rev/min
0 01 80.0 82.5 80.0 82.5
001.5 85.5 84.0 84.0 84.0
002 86.5 84.0 85.5 84.0
003 87.5 87.5 86.5 86.5
005 87.5 87.5 87.5 87.5
007.5 89.5 89.5 88.5 88.5
010 89.5 89.5 90.2 89.5
015 90.2 91.0 90.2 91.0
020 90.2 91.0 91.0 91.0
025 91.7 92.4 91.7 91.7
030 91.7 92.4 92.4 92.4
040 93.0 93.0 93.0 93.0
050 93.0 93.0 93.0 93.0
060 93.6 93.6 93.6 93.6
075 93.6 94.1 93.6 94.1
100 94.1 94.5 94.1 94.1
125 94.1 94.5 94.1 94.5
150 95.0 95.0 94.5 95.0
200 95.0 95.0 94.5 95.0

Courtesy General Electric Company Bulletin No. GEP-500Q

All electric motor companies must develop a bell curve of efficiency
distribution where the minimum or guaranteed efficiency can only be
10 percent less than the nominal efficiencies shown in Table 7.3. Some
manufacturers list this minimum efficiency on their motors as the
guaranteed efficiency. Motors manufactured prior to October 1997
should comply with the efficiencies listed in NEMA Bulletin G-1-1993.
Table 7.4 provides efficiencies for NEMA PREMIUM ™ Efficiency
motors. Both minimum and nominal efficiencies are shown. Most
motor manufacturers guarantee the nominal efficiency. Generally, pre-
mium efficiency motors cost around 10 percent more than the stan-
dard motors of Table 7.3; in return, the efficiency will be improved by
more than 1 percent. It is up to the HVAC system designer to deter-
mine the feasibility of the investment in premium efficiency motors.

7.2.10 Wire-to-water efficiency for constant
speed pumps
Wire-to-water efficiency will be discussed in detail in Chap. 10.
Basically, it is the energy imparted to the water divided by the energy
input to the motor. For individual pumps, it is simply the efficiency of
the motor multiplied by the efficiency of the pump.

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