Eurotherm 590SP, Product Manual

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Chapter 3 Installation and Wiring
590SP Digital Product Manual
3 - 10
3
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Microtachs
Fiber optic encoders (or Microtachs) come in either glass or plastic. While the 5901 glass Microt-
achs (5901) can transmit a feedback signal over a long range without a repeater, they require a
special termination tool to properly cut and polish the glass fiber optic cable. The 5701 Microtach is
used with plastic fiber optic cable which needs only a set of pliers for termination. The signal range
for plastic, however, is limited and may require a Microtach repeater. Repeater part numbers are
listed in Appendix A.
Each type of Microtach requires its own receiver card, listed above and can be powered directly
from the drive's +24 VDC supply or from an external source. Refer to Appendix A for terminal
designations and technical and installation details.
One-half inch diameter composite plastic fiber optic cable is available for the 5701 plastic fiber
optic Microtach only. The cable includes two 16 AWG conductors with a plastic fiber optic conduc-
tor sheathed in a protective plastic coating. The cable is recommended when running plastic fiber
optic within conduit. Refer to Appendix A for part numbers.
CALIBRATION
Calibrate the drive's armature current, armature voltage and speed feedback after installing and wiring the drive. Be
sure to record these settings after they are correctly set and again after start up. The four DIP switches S1, S2, S3 and
S4 scale the drive for the motor armature voltage. The rotary switches S5, S6 and S7 calibrate the drive for the motor
current. The switches are located at the lower center of the control board, as shown in Figure 3.5. A close up view is
shown in Figure 3.8.
WARNING!
Do not make any changes in calibration settings with the drive contactor energized. Altering the drive
calibration while running can cause mechanical damage and/or injury to personnel.
WARNING!
Do not exchange drives without first verifying that the new drive's calibration matches the motor's
nameplate rating. Equipment damage or injury to personnel could result from incorrect calibrations.
Glass vs. Plastic
Microtach Supply
Requirement
Composite FO
Cable
Figure 3.8 - Current and Voltage
Calibration Switches
Voltage &
Current Cal
Switch Locations
▼
Microtach Option
W
NOTE. Calibration for 2 HP,
180 VDC armature motor shown
(Ratings Source: 1990 NEC,
Table 430-147).