Honeywell 221508A2 Resistor Board

The Honeywell 221508A2 Resistor Board is a critical field-installable component designed for Series 90 Modutrol IV motors. This specialized Honeywell resistor board assembly enables advanced motor sequencing and multi-actuator control from a single signal source. It serves as the direct replacement for Legacy Honeywell 4074BYK and 4074EED resistor kits, providing a unified solution for modernizing existing HVAC damper and valve actuator arrays. When integrated into a Modutrol IV motor's wiring box, this board allows a single Series 90 controller to operate up to six motors in parallel. For systems utilizing electronic inputs, the 221508A2 can be field-configured to adapt M91XX motors to 4-20 mA signals or interface with W973 logic panels, effectively driving up to four or three motors respectively. This board ensures precise signal distribution across Honeywell Modutrol IV motor accessories, maintaining operational stability in ambient temperature ranges from -18°C to +55°C without signal degradation.

Key Benefits

• Universal Multi-Motor Control: Configure a single Honeywell 221508A2 to drive up to 6 Modutrol IV actuators in parallel from a 135-ohm Series 90 controller.
• Signal Adaptation: Seamlessly converts M91XX motors to accept 4-20 mA DC input signals, eliminating the need for separate external transducers in Honeywell motor control setups.
• Direct Replacement Logic: Engineered as a high-reliability successor to 4074BYK and 4074EED (Mod IV version), ensuring zero-gap compatibility during retrofit applications.
• Simplified Field Wiring: Features rugged screw terminals and a plug-on design that mounts directly to the motor's quick-connect terminals inside the wiring box.
• High Environmental Tolerance: Designed for demanding mechanical rooms with a wide operating temperature range for consistent HVAC actuator resistor board performance.

Common Questions

Can I use the 221508A2 to drive different types of motors simultaneously?
This board is specifically designed for Series 90 Modutrol IV Motors. All motors in the parallel sequence should be of the same series to ensure synchronized stroke and timing. Mixing motor series may result in uneven positioning or signal loss.

How many motors can I control with a 4-20 mA signal using this board?
When configured for 4-20 mA applications, a single Honeywell 221508A2 board allows for the operation of up to four M91XX motors in unison, provided the controller's current output is sufficient for the total impedance.

Does this board require an external power source?
The board typically draws its reference from the motor's internal transformer or the Series 90 controller. Always verify if the motor transformer secondary wires (T1, T2) need to be redirected to the board terminals during installation based on your specific 120V or 24V configuration.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.