3
Introduction
The 231 Spindle Amplifier was designed to be used with the MPM1094R-1092 spindle motor.
This motor is wound in a WYE configuration with four windings in each leg of the WYE that are
connected with a system of relay switches mounted on the side of the motor that change the
motor KE and KT. This allows up to 20 horsepower in four speed ranges, eliminating the need
for any complex mechanical gear reductions.
The TAC output of the amplifier is scaled to the speed ranges as follows:
Low Speed 1
690 rpm
TAC output = .69 volts
Med Low Speed 2
1630 rpm
TAC output = 1.63 volts
Med High Speed 3
3300 rpm
TAC output = 3.3 volts
High Speed 4
6600 rpm
TAC output = 6.6 volts
The amplifier features overcurrent sensing which will cause the amplifier to shut down and
produce an overcurrent fault if the continuous current rating of the amplifier is exceeded by
20%.
The amplifier also has an I/O selectable orient feature which causes the motor shaft to rotate
at a fixed 1 rev per sec rate in a CCW direction viewed from the shaft end of the motor.
Ramping of the command input signal for a time period that is user selectable using DIP
switches from 2 to 10 seconds, can be enabled and disabled through the I/O connector.
An analog dc voltage output that is proportioned to the output current.
The CONT (continuous) horsepower is available continuously. The INT (intermittent)
horsepower is available for 3-5 minutes. Operation above the CONT rating will result in a
motor thermal fault condition. The ratings indicated are for motors applied with fan cooling. If
the fan is not used, the ratings have to be deteriorated by 20%.
Spindle Sizes Available
CONT
INT
Required
Amplifier
Amplifier Input
Voltage
Required
Motor
13
24
MPA-75-SPN
230 Vac
MPM1904R-1092
* This combination of amplifier and motor require the insertion of external inductors in the RST leads of
the motors. These inductors deteriorate high speed torque. On the high speed winding, horsepower
ratings are typically 1/2.
There are other 230 Vac amplifiers and motors, but they must be configured as factory
specials.
