PRODUCT DATA
63-2631
Series 90
Modutrol IV™ Motors
APPLICATION
The Series 90 Modutrol IV™ Motors are spring return and 
non-spring return modulating proportional control motors. Use 
these motors with controllers that provide a Series 90 output 
to operate dampers or valves.
FEATURES
• Replaces M934A,D, M941, M944A,C,D, M945A,D,F, 
M954, M965, and M975 motors.
• Integral junction box provides NEMA 3 weather 
protection.
• Integral spring return returns motor to normal position 
when power is interrupted.
• Motor and circuitry operate from 24 Vac. Models 
available with factory installed transformer, or a field 
added internal transformer.
• Quick-connect terminals are standard—screw terminal 
adapter is available.
• Adapter bracket for matching shaft height of older 
motors is available.
• Motors have field adjustable stroke (90° to 160°).
• Die-cast aluminum housing.
• Integral auxiliary switches are available factory 
mounted, or can be field added.
• Nominal timing standard of 30 seconds (90° stroke), 
and 60 seconds (160° stroke). Other timings available.
• Spring return motors can operate valve linkages form 
power end or auxiliary end shafts for normally closed 
or normally open valve applications.
• All models have dual shafts (slotted and tapped on 
both ends).
• All models have auxiliary switch cams.
• Fixed torque throughout the entire voltage range.
• Motors are designed for either normally open or 
normally closed valves and dampers.
• Field addable interface modules can be mounted in the 
junction box to upgrade the motor to Series 70 
(electronic) control.
Contents
Application ........................................................................ 1
Features ........................................................................... 1
Specifications ................................................................... 2
Ordering Information  ........................................................ 2
Installation ........................................................................ 5
Settings and Adjustments ................................................. 7
Operation .......................................................................... 10
Checkout .......................................................................... 12
Replacement .................................................................... 12