Voltage feedback, load changes are compensated for by an “IR” compensation
circuit which senses any increase in armature current and raises the armature
voltage to compensate for the increased voltage drop in the motor armature. This
circuit thus controls the regulation (speed changes) due to load changes. The
motor current is continuously monitored by a very low resistance current shunt.
The signal from this shunt, which is also used in the torque loop, is then fed to the
“IR”circuit, which permits the achievement of no load to full load regulation of
less than 1% of base speed. In applications requiring load regulation better than
1% of base speed, tachometer feedback must be used.
The OC2 unit is protected against excessive current overloads by the
outstanding OC2 torque (current) limit circuitry. In addition, the OC2 unit
is protected against damage due to accidental wiring shorts or grounds by
fast-acting rectifier-protection type fuses inserted in the AC input lines.
********************************************************
WARNING
IF FUSE REPLACEMENT BECOMES
NECESSARY, USE ONLY THE SPECIFIED
FUSES. THE USE OF SUBSTITUTE FUSES
MAY VOID CONTROL WARRANTY
*******************************************************
2
