Rockwell Automation MinPak Plus DC Drives Kits User Manual

Page 31

Step 6 Ċ Replace the Circuit Breaker bracket and reconĆ

nect the leads disconnected in Step 3.
6.4 Voltage/Tachometer Follower Ċ The Voltage/

Tachometer Follower Kit allows the Regenerative MinPak

Plus to be controlled automatically in response to a

speed reference generated by a tachometer connected

to an entirely separate machine unit. Ideal applications

include automatic control systems where a second"

slave drive must closely follow the speed of a master

drive, or machine. (Refer to Figure 6.7).

Figure 6.7 - Voltage/Tachometer Follower

The kit is designed to accept an input signal of 25 to 250

VDC to obtain maximum speed. (The maximum permisĆ

sible input voltage is 250 VDC.) The input impedance beĆ

tween terminals is approximately 80,000 ohms. ThereĆ

fore, 100 VDC draw approximately 1.25 mA current from

the voltage source.
The Kit contains the Module and a mounting screw. AlĆ

though the Regenerative MinPak Plus can use the Kit for

exclusive automatic speed control, if manual override

control is needed, an AUTO/MANUAL selector switch

must be used on the Operator Control Station, Local or

Remote. (Refer to Table 2.B.) In the MANUAL position,

the drive response to the SPEED potentiometer setting.

In AUTO, it follows only the external signal and does not

respond to manually input speed change commands.
The user must also supply required lengths of the speciĆ

fied signal wire. (Refer to Table 6.C.) No other equipment

is necessary although some changes may be necessary

on the Module.
Step 1 Ċ In general, follow the wiring procedures outĆ

lined at Paragraphs 3.7 and 4.2.4, but keep in mind that

there are location and wire routing differences. Draw the

twistedĆpair signal wires into the Chassis through the

designated conduit entry. (Refer to Figure 3.7.) Run the

wires up as shown.
Step 2 Ċ Orient the Voltage/Tachometer Follower ModĆ

ule over the REFERENCE area on the Regulator Module,

just over the 5 pins. (Refer to Figure 7.6.) Lower it so that

the pins pass through the guides on the Module. (It may

be necessary to remove a protective plastic cap from the

pins.) Secure the Module with the screw.

Step 3 Ċ Connect the wires from the tachometer to the

terminal strip on the Module. Plus (+) is on the left, minus

(-) on the right. Do not strip more than 1/8 inch (3mm)

of insulation off since shorts occur at exposed points.

Maintain the twisted character as long as possible.
Step 4 Ċ If an AUTO/MANUAL selector switch is used,

it is necessary to remove jumper J1 on the Module. (ReĆ

fer to Figure 6.8.) If, however, the controller is designed

to run automatically without manual speed control, J1

remains in place. In addition, remove jumper J4 on the

Regulator Module if an AUTO/MANUAL selector switch

is used.

Jumper J1

Figure 6.8 - Jumper J1

Step 5 Ċ This Step assumes that the complete drive sysĆ

tem, including the controller, has been successfully

started up and debugged according to Section 4 thru

Paragraph 4.4.1. It is not necessary to carry out a powerĆ

on test. Start the drive and place it in the AUTO mode, if

so equipped.
With a small, insulated screwdriver, adjust the AUto

Speed Calibration potentiometer on the Tachometer/

Follower Module until the drive reaches the desired

speed in relation to the reference input signal being reĆ

ceived.

DANGER

APPLICATION MUST NOT RELY ON ZERO

SPEED/INPUT SETTING FOR SAFETY. SERIOUS

OR FATAL INJURY MAY RESULT.

6.5 Instrument Interface/Preset Speed Ċ The RegenĆ

erative MinPak Plus can automatically follow a milliamĆ

pere signal from a process control instrument if the opĆ

tional Instrument Interface/Preset Speed Kit is installed.

(Refer to Figure 6.9.) Alternately, the Kit also permits the

drive to run continuously at a preselected speed.
The Instrument Interface Module accepts a 0 to 5, 1 to 5,

4 to 20 or 10 to 50 mA signal, which may be grounded

or ungrounded. The maximum input is 50 mA.
Typical applications include cases where the drive moĆ

tor's speed must be controlled and varied as a function

of such process variables as temperature, weight, fluid

flow and pressure.