Rockwell Automation MinPak Plus DC Drive User Manual User Manual
Page 68
B:2
NEMA Definitions:
NEMA Type 4 is generally defined as an indoor/outdoor enclosure that is watertight and
dustĆtight. It is designed to protect against splashing and hoseĆdirected water within
specific test limitations.
NEMA Type 12 is generally defined as an indoor enclosure that is dustĆtight and oilĆtight. It
is designed to resist fibers, filings, dust, dirt and light oil splashing.
RPM:
Revolutions per Minute Ć The number oftimes per minute the shaft ofthe motor (machine)
rotates.
Service Factor (SF):
When used on a motor nameplate, a number which indicates how much above the
nameplate rating a motor can be loaded without causing serious degradation, (i.e. a 1.15
SF can produce 15% greater torque than a 1.0 SF rating ofthe same motor).
Tachometer:
A small generator normally used as a rotational speed sensing device. Tachometers are
typically attached to the output shaft of a motor requiring close speed regulation. The
tachometer feeds its signal to a control which adjusts its input to the motor accordingly
(called closed loop feedback" control).
Thermostat:
Units applies directly to the motor's windings which senses winding temperature and may
automatically break the circuit in an overheating situation.
Torque:
Turning force delivered by a motor or gear motor shaft, usually expressed in poundsĆfeet:
lbs.ft. = HP x 5250 / RPM = full load torque