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SIMILAR PRODUCTS
SGMKH-20A2A2SX USAIKM-60-ES33 USAIKM-60-ES33 USAIKM-60-ES13
SGMG-09VSACS SGMAH-02A1A4C SGMAH-A8A1A-YB11
SGMAS-A5ACA2C SGMAH-A5B1A-YB11 SGMAH-A5A1A-YB11
USAFED-05C32KE USAFED-05-MU11 USAFED-20FB2 USAFED-09FS13
USAIFM-10-ES11 USAFED-03CS2T USAFED-30C22OE R20315-8X4-04
USAFED-09FA1S USAFED-44CS2 USAREM-02CE2K USAIKM-60-3U11
USAIKM-60-ES15
SGMG-13ASR SGM-02AWSU13 SGM-02AWSU12 SGMG-20A2AB SGMAH-A8B1A-YB11
SGMAH-01AAA21 SGM-02AW12B SGMPH-08A1A6B SGM-A5A8YR12
SGMG-12A2BBB SGMG-12A2BBB SGMP-02AW14B SGM-02AW14B SGMP-04AW14
USASEM-03AS2S USAMED-20MS2S SGMP-04AW14B
SGMGH-09ACB01 SGMAS-08A2A6E SGMPH-02A1A-YR11 SGMAS-01A2A61
SGMAS-A5A2A61 SGMAS-04A2A6C SGMM-A1313 SGMM-A3313 SGMAH-01AAF41
USAFED-05FA1 SGM-04A3NT12 SGMAH-01AAA2H USAFED-20C220E
SGMAH-01BAA21 SGMAH-04AAA-SL11 USAFED-03FA1
USAFED-05FA1 SGML-04AFSL11 USAFED-05FD1 SGMAS-A5A2A6S
USAFED-02FB2 SGMM-A2C3YK11 SGMPS-02ACA4C SGMAS-08ACA21
SGMAS-12ACA21 SGMG-75A2A USAFED-05FD1C
USAFED-03FD1 USAHEM-03-SL15 SGM-A2C3J26
SGM-04A3FJ52 SGM-A5CWYB11 USAFED-44C22K
Standard (Non-Time Delay, Single Element) Fuses
Standard fuses protect against short circuits and ground faults
using thermal features to sense a heat
buildup in the circuit. Once blown standard fuses are no longer
usable and must be replaced..
NEMA design A and B motors up to 500 hp in size are required to
have a full-load efficiency value (selected froma table of nominal
efficiencies) stamped on the nameplate. Most analyses of motor
energy conservation savingsassume that the existing motor is
operating at its nameplate efficiency. This assumption is
reasonable above the50% load point as motor efficiencies generally
peak at around 3/4 load with performance at 50% load
almostidentical to that at full load. Larger horsepower motors
exhibit a relatively flat efficiency curve down to 25% of fullload.
It is more difficult to determine the efficiency of a motor that
has been in service a long time. It is not uncommon for the
nameplate on the motor to be lost or painted over. In that case, it
is almost impossible to locate efficiency information. Also, if the
motor has been rewound, there is a probability that the motor
efficiency has been reduced.
When nameplate efficiency is missing or unreadable, you must
determine the efficiency value at the operating load point for the
motor. If available, record significant nameplate data and contact
the motor manufacturer. With the style, type, and serial number,
the manufacturer can identify approximately when the motor was
manufactured.
Often the manufacturer will have historical records and can supply
nominal efficiency values as a function
of load for a family of motors.
When the manufacturer cannot provide motor efficiency values, you
may use estimates from Attachment C.
Attachment C contains nominal efficiency values at full, 75%, 50%,
and 25% load for typical standard efficiency motors of various
sizes and with synchronous speeds of 900, 1200, 1800, and 3600 rpm.
Attachment C indicates“industry average” full- and part-load
performance for all standard efficiency motors currently on the
market.
Three steps are used to estimate efficiency and load. First, use
power, amperage, or slip measurements to
identify the load imposed on the operating motor. Second, obtain a
motor part-load efficiency value consistent with the approximated
load either from the manufacturer or by interpolating from the data
supplied in Attachment C. Finally, if direct-read power
measurements are available, derive a revised load estimate using
both the power measurement at the motor terminals and the part-load
efficiency value as shown in Equation 8.
