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ECM Motor - troubleshooting Manual
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priceindustries.com
ECM MOTOR
TROUBLESHOOTING
NOTE:
If a motor has a 120 VAC power cable (with a jumper)
and 240/277 VAC is supplied to the motor it will be destroyed!
ECM Standard Speed Controller
All ECM Speed Controllers are manufactured by Price
Electronics in Winnipeg. It allows for ON/OFF and 0-100%
speed control of any ECM motor (120/240/277 VAC, all HPs).
ECM Speed Controllers have 2 modes. Manual adjust and
BAS (BAS stands for Building Automation System).
Manual Mode
On a standard ECM speed controller, manual mode the
speed is controlled by adjusting the potentiometer (POT). The
POT can adjusted from 0-100%. To set the POT precisely
the voltage output must be measured. Using a standard
multimeter on a DC voltage setting the (+) and (-) tabs on the
board can be measured. The output is 0-5 VDC.
POT Voltage
Motor
0 - 1 VDC
Off
1 - 4.5 VDC
0-100% Control
4.5 - 5 VDC
100%
SAMPLE LABEL applied to factory programmed motor
For each type of terminal unit and fan coil, there are equations
in the unit’s service and installation manual that will relate the
airflow in CFM to the voltage measured across the taps on the
fan speed controller. For example:
A size 50 FDCA2 terminal unit with 277 volt ECM equation is
as follows: CFM = 672.29 (VDC) – 572.45
So, in order to get 1400 CFM, we would need to rearrange the
equation to get: (CFM+572.45) / 672.29 = VDC
The POT would have to be turned up until the voltage
measured at the taps is 2.94 VDC
Measure (+) VDC
Measure (-) VDC
Range is 0-5 VDC
FIGURE 1 - ECM SPEED CONTROLLER (MANUAL SETTING)