Rockwell Automation FlexPak Plus NRG DC Drive User Manual

Page 18

4.3.3. Minimum Speed (Voltage) - The Minimum

SpeedPotentiometer on the regulator has been factory

preset for drive minimum speed, 5%. By means of adĆ

justment, this speedmay be raisedor lowered. The reĆ

sult is the lowest moving speedthe operator can set on

the SPEED dial. The control range is 5% to 30% of rated

speed.
Again, the motor speedcan be determinedwith a

tachometer.
With the SPEED dial at zero position and using a small,

insulatedslot screwdriver, carefully turn the Minimum

SpeedPotentiometer until the desiredminimum is

reached. Note that CW represents an increase; CCW

represents a decrease.
NOTE: Carefully recheck the maximum speed adĆ

justment for desired setting Since the maximum and

minimum speed adjustments are interactive, a

change in one affects the other. At times, it may be

necessary to work back and forth for precise adjustĆ

ments.
4.3.4 Accelerationand DecelerationRates - The AcĆ

celeration andDeceleration Rate Potentiometers on the

Regulator Module have been factory preset for a typical

linear acceleration rate of six seconds to maximum and

minimum speed. This time can be adjusted over a range

of 0.5 to 30 seconds from a fully stopped condition.

4.3.5 Current Limit - Although it will probably not be

necessary to make any adjustment in the factoryĆset

current limit value of 150% of ratedload, it is possible to

change this governing value. (Individual application

speedchanges or loadchanges on sustainedoverĆ

loads may require readjustment. Also, applications reĆ

quiring torque limiting or accelerating of high inertia

loads may require a change from this value.)
To reduce the torque output of the drive, turn the Current

Limit Potentiometer CCW. Note, however, that turning

CCW too far may prevent the drive accelerating to the

desired speed.
4.3.6 IR Compensation - IR (voltage) Compensation

is a feature which makes up for the armature resistance

of a motor that causes a drop in speedas the loadis inĆ

creased. The IR Compensation Potentiometer is factoĆ

ryĆset at zero. The IR compensation feature can be adĆ

justedbetween O and12% of ratedloadandis used

only for a voltage regulation mode. When using a

tachometer feedback, the IR Compensation PotentiomĆ

eter must be turnedcompletely CCW.

CAUTION: If the IR Compensation Potentiometer

is set too high, motor speedrising characteristics

may result. Instability andoscillation in motor

speedwill result.