Elegantly simple low-cost retrofit method and system for replacing a constant torque electronically commutated motor with a fix-speed permanent split capacitor motor
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Solution Overview
Problem
The challenge lies in replacing a failed constant torque Electronically Commutated Motor (ECM) in air conditioning systems without requiring an exact OEM replacement, as each OEM programs torque settings uniquely, making it difficult for technicians to use generic motors due to proprietary control methods and complex rewiring needs.
Innovation Solution
A low-cost control board system that allows the use of a permanent split capacitor (PSC) motor, which is simpler and less expensive, by connecting power leads to selected speed taps, eliminating the need for rewiring and complex electronics, and using a universal control board to activate the PSC motor at the installer's chosen speed, independent of OEM programming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a constant torque ECM is replaced with a generic motor, then cost is reduced and availability is improved, but the motor cannot operate correctly due to proprietary torque settings
Solution Approach 1:
The patent creates a universal replacement motor system that can work with multiple OEM systems. The generic PSC motor is paired with an adapter board that translates different OEM control signals into a standardized interface, allowing one motor design to serve multiple functions across different manufacturers' systems without requiring OEM-specific programming
Solution Approach 2:
The adapter board serves as an intermediary between the generic PSC motor and various OEM control systems. It translates proprietary torque settings and control signals from different manufacturers into a universal interface that the PSC motor can understand, eliminating the need for direct OEM-specific motor programming
2Device complexity
If ECM is replaced with PSC motor, then device complexity is reduced and cost is reduced, but control precision over variable airflow is lost
Solution Approach 1:
The system dynamically adapts the fixed-speed PSC motor to provide variable airflow control by using the adapter board to interpret different control signals (such as cycling the motor on/off at different rates) that simulate variable speed operation, thereby achieving dynamic airflow control with a statically simple motor
3Reliability
If technician uses OEM-specific replacement motor, then airflow consistency is maintained, but repair time increases and return trips are required
Solution Approach 1:
The patent employs a disposable adapter board that is inexpensive and can be quickly installed to bridge the gap between generic motors and OEM systems. This allows technicians to use readily available generic motors without needing to stock expensive OEM-specific parts, reducing repair time and eliminating return trips while maintaining functional equivalence
Data Source
AI summary
A system and method are provided to allow the replacement of a costly electrically commutated blower or fan motor with a less efficient motor such as a permanent split capacitor motor operating at a predetermined speed, without regard to the specific electrically commutated motor command signals or programming being used by the original equipment manufacturer. A retrofittable control board is employed to activate the replacement motor by energizing the replacement blower motor when an electrically commutated blower motor command signal is observed on any one of the signal lines which are continuously monitored simultaneously.