NOTE: Series 3 Motors are shipped with auxiliary switch
cams that permit acceptance of 220736A,B Inter-
nal Auxiliary Switch Kits. Refer to Form no. 63-
2228 for 220736A,B Installation Instructions.
Auxiliary Switch Adjustment
1. Remove the top cover from the motor to gain access to
the motor terminals and auxiliary cams.
2. Disconnect the controller from the motor.
3. Connect a potentiometer to the motor as shown in Fig. 6.
4. Using the potentiometer, drive the motor to the position
where the auxiliary equipment is to be switched.
5. For a 1° switch differential, check continuity of the auxil-
iary switch contacts R-B and rotate the cam as follows:
a. If the contacts are open, rotate the cam clockwise
until the R-B contacts close.
b. If the contacts are closed, rotate the cam counter-
clockwise until the R-B contacts open.
6. For a 10° switch differential:
a. Spring return models: rotate the cam approximately
180° so that the slow-rise portion of the cam actu-
ates the switch. Then check continuity of the auxiliary
switch contacts R-B.
b. Non-spring return models: check continuity of the
auxiliary switch contacts R-B.
7. Rotate the cam as follows:
a. If the contacts are open, rotate the cam counter-
clockwise until the R-B contacts close.
b. If the contacts are closed, rotate the cam clockwise
until the R-B contacts open.
8. Check for proper auxiliary equipment differential and
switching by driving the motor though the full stroke in
9. Disconnect the potentiometer, reconnect the controller,
and replace the motor top cover.
NOTE: Changing the differential from 1° to 10° reverses
the switching action. For example, with a 10° dif-
ferential, switch contacts R-B make and R-W
break on a counterclockwise (closed) rotation.
With a 1° differential, switch contacts R-W make
and R-B break on a counterclockwise (closed)
Use Series 90 Modutrol IV Motors for standard Series 90
operation (See Table 12):
1. Two potentiometers, one in the controller and one in the
motor, along with the motor resistor network, form a
bridge circuit. As long as the value of the controlled
medium remains at the setpoint, the circuit remains bal-
anced and the motor does not run.
2. When the controlled medium value changes, the control-
ler potentiometer wiper moves, unbalancing the bridge
3. The imbalance is amplified and the microcontroller then
drives the motor in the direction necessary to correct the
controlled medium change.
4. As the motor shaft rotates, it turns the feedback potenti-
ometer, rebalancing the bridge circuit, stopping the
Table 12. Modutrol IV Motor Operation.
Open W and short
or Spring Return
R to B
Open B and short
R to W
Non-Spring Return Power Loss
Fig. 12. Attaching a Shunt Resistor to TRADELINE Motors.
Table 13. Cam Arrangements.
All Other M91XX
SERIES 90 MODUTROL IV
drives to midstroke