Eurotherm Drives 590 DRV Digital, Product Manual, Page: 50 / 318

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Chapter 4 Start-up and Adjustment
590 DRV Digital Drive Product Manual
MOTOR ROTATION CHECK
This procedure verifies that the motor shaft rotates in control and in the desired direction.
1. Set SETUP PARAMETERS:: CURRENT LOOP:: CURRENT LIMIT to 0%.
2. Start the drive and set your drive speed reference potentiometer to +1.0 VDC or +10%. Make certain
that any trim speeds or additional setpoints are set to 0%. Check that DIAGNOSTICS:: SPT. SUM
OUTPUT is 10%. You can monitor all the drive's speed references under SETUP PARAM-
ETERS:: SPEED LOOP:: SETPOINTS.
3. Slowly increase SETUP PARAMETERS:: CURRENT LOOP:: CURRENT LIMIT to approximately
20%.
4. The motor speed should increase to 10% speed in the desired direction. If the feedback or field polarity
is incorrect, the motor will either run away, or run in control in the wrong direction. If either situation
occurs, stop the drive, disconnect the main supply and external field supply (if used) and check the
following:
a. For motors fitted with analog DC tachometer generators:
• Did the motor run away in the correct direction? Reverse the tachometer generator wires.
• Did the motor run away in the wrong direction? Reverse the field connections.
• Did the motor rotate in the wrong direction but at the correct speed? Reverse both the field and
tachometer generator connections.
b. For motors fitted AC tachometer generators:
• Did the motor run away in the correct direction or in the wrong direction? Reapply power and
check the speed setpoint. Because an AC tachometer generator provides a unipolar output
regardless of direction of rotation, the drive is limited to speed control in one direction only.
This speed reference must be positive. If the motor ran away in reverse, provide a positive speed
reference and reverse the field connections.
Caution
A runaway condition always exists when using an AC tachometer generator on a regenerative
model DC controller, even if the speed reference is always positive. To avoid this problem, use
the 591SP (non-regenerative) drive on a motor with an AC tachometer generator. Or, use the
regenerative 590 DRV Digital drive and disable the drive's reverse bridge thyristors under
SETUP PARAMETERS:: CURRENT LOOP:: REGEN MODE.
• Did the motor rotate in the wrong direction but at the correct speed? Reverse the field connections.
c. For motors fitted with 5701/5901 Microtachs or wire-ended electrical encoders:
• Did the motor run away in the correct direction? Reconnect the drive supply and change the
feedback sign by setting SETUP PARAMETERS:: SPEED LOOP:: ENCODER SIGN to POSI-
TIVE or NEGATIVE as required.
• Did the motor run away in the wrong direction? Reverse the field leads.
• Did the motor rotate in the wrong direction but at the correct speed? Reverse the field connec-
tions, reconnect the drive supply and reverse the feedback sign by setting ENCODER SIGN to
POSITIVE or NEGATIVE as required.
Caution
When changing set up parameters (such as feedback polarity), be certain to save the change
before disconnecting control power or the set up will be lost.
DC Tach
AC Tach
NON-regen only
for AC Tachs
Set I limit to 0%
Set Speed Demand
to 10%
Start Drive
Increase I limit to
20%
Microtach/
Encoder
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