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APPENDIX D — EVO/ECM 4-SPEED ADJUSTMENT
Fig. I — 4-Speed ECM
Adjusting the Flo1, Flo2, Flo3 potentiometers requires the use of a
multi-meter capable of measuring 0~5 vdc.
1. Only trained and qualified individuals should attempt to
adjust or service components on any electrical component.
Failure to follow safety rules could result in electrical shock
or hazard.
2. 24 vac power must be supplied to ECM board to make adjust
-
ments.
3. Set the electrical multi-meter to volts direct current (vdc) on
the 0~5 or 0~20 vdc scale.
4. Attach black (negative) lead of meter to the “Com” terminal
to the left of the potentiometers and below the status light.
5. Attach the red (positive) lead of the meter to the high speed
“Flo1” terminal below the potentiometer.
6. High Speed: Using a small screwdriver, turn the Flo1 potenti
-
ometer so the meter measures 4.51 vdc. This will set the
ECM speed to 90% of maximum for high speed operation.
7. Medium Speed: Using a small screwdriver, turn the Flo2
potentiometer so the meter measures 3.53 vdc. This will set
the ECM speed to 70% of maximum speed for medium speed
operation.
8. Low Speed: Using a small screwdriver, turn the Flo3 potenti
-
ometer so the meter measures 2.06 vdc. This will set the
ECM speed to 40% of maximum speed for low speed opera
-
tion.
9. For setting of Flo0 and Flo4, contact Carrier, otherwise these
potentiometers should be set to full counter-clockwise
rotation.
Flo 1, 2, and 3 Terminals
Flo 0 and 4 Terminals
Com
Pot Adjustment
Flo 1, 2, and 3
(in the Field)
Pot Adjustment
Flo 0 and 4
(Contact Factory)