Manually Adjusting The Fan Motor Speed - A.O. Smith 710 ASME Service Manual

12-16. Manually adjusting the fan motor speed

While the FM+ dipswitch will automatically increase the fan speed by 7.5%, the fan motor speed on
the 710 can also be manually adjusted. In order to perform manual adjustments to the speed, a
remote controller is required.
Manually adjusting the fan motor speed of the 710 will change the amount of intake air for
combustion, which can cause excess CO emission from the exhaust chamber if the fan motor
speed is set incorrectly. Therefore, this procedure should never be performed unless the
Technical Services Department has given consent and authorization.
WARNING
Adjusting maximum fan motor speed
1. While 710 is in operation, set dipswitch No.4 on computer board to the "ON" position. (Figure 1)
2. On the temperature remote controller, display mode #3 (fan motor speed) by entering the
"Diagnostics mode" (Refer to Section 12-1).
3. Press and hold down the "MAX" button on the computer board. While holding down the "MAX"
button, press either the "Increase" or "Decrease" button to increase or decrease the fan motor speed,
respectively (Figure 2). Refer to the remote controller display to verify that speed has been set to
desired value.
4. After fan speed has been set, set dipswitch No.4 back to the "OFF" position.
Adjusting minimum fan motor speed
1. While 710 is in operation, set dipswitch No.4 on computer board to the "ON" position. (Figure 1)
2. On the temperature remote controller, display mode #3 (fan motor speed) by entering the
"Diagnostics mode" (Refer to Section 12-1).
3. Press and hold down the "MIN" button on the computer board. While holding down the "MIN"
button, press either the "Increase" or "Decrease" button to increase or decrease the fan motor speed,
respectively (Figure 2). Refer to the remote controller display to verify that speed has been set to
desired value.
4. After fan speed has been set, set dipswitch No.4 back to the "OFF" position.
Figure 1
Right bank of dipswitches
Right bank of dipswitches
MAX button
MIN button
Increase button
Decrease button
69
CONFIDENTIAL
710 / 710 ASME Service Manual
Figure 2
Computer board
Ver. 1.00