Hoffman Controls 763-ECM EC Motor Speed Control

The 763-ECM controls the speed of variable speed EC motors using the motor’s built-in tachometer signal. Control can be locally using the LED display and the buttons on the control, or it can be done remotely via the Modbus RTU interface. Control of the speed can be manual (open loop) or automatic (closed loop).

In manual mode, a speed index (0-100) is used to set the control signal to the motor. Both the speed index and the motor rpm are visible on the LED display and over the Modbus. In automatic mode, the motor rpm is set directly, and the control uses a PI feedback algorithm to drive the motor rpm, as sensed by the tachometer signal, to the set value, independent of loading on the motor.

The control has two outputs that may be used to control the motor: a 0-10VDC output and a PWM output (0-17 volt, 80 Hz). Each output can supply up to 10 mA to drive the motor. A “GO” signal is also provided for motors that require this.

The 763-ECM is available as a PCB in standoff and panel mount configurations.

 Specifications

• Voltage Input: 22-30 VAC
• Power: 4VA
• Current Output (0-10 Vdc or, PWM):  10 mA
• Frequency: 60Hz
• Input: EC motor’s tach signal
• Outputs: 0 – 10Vdc, 17 volt [80 Hz] PWM
•                and 17,5 Vdc switched or 20 Vdc
•                continuous “GO” signal
• Adjustments: RPM
• Operating Methods
•       Local or Remote modes             Manual or Automatic
• Environment
•     Operating, non-condensing          32F to 125F
•                                                           0C to 52C
• Dimensions (L x W x H) – 5.56 x 3.32 x 1.25″
• models: 763-ECM                          Standoff Mount
•               763-ECM(P)                     Panel Mount
•               763-ECM (MOD)              Standoff Mount w/ Modbus
•               763-ECM (MOD)P           Panel Mount w/ Modbus

• • • Control the speed of an ECM motor locally or remotely
    • MODBUS RTU communication with building automation systems
    • Closed-loop control mode will maintain motor speed independent of loading
    • Open-loop control mode will set the percent of maximum control signal (speed index)
    • LED display of motor rpm
    • PWM and DC outputs plus GO Signal
    • Panel mount or free-standing models
    • Large, easy to read LED display
    • All parameters can be set or read remotely, and all input and output values can be read remotely
    • Modbus baud rate, slave ID, and parity can be set locally
    • Simple field installation
    • Simple operation