Commissioning – Servo Setup 3-49
FlexFit – Linkageless Control – Revision 1.0
PREFERRED
UTILITIES MFG CORPORATION
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WARNING
If the burner has been commissioned previously, re-zeroing a servo changes
all combustion curves that use this servo. The technician must re-vali-
date (and adjust if necessary) the affected curves in commissioning mode
before the burner can be operated in run mode. The burner will lockout
if a start-up is attempted with any unveried curve points.
The servos are now individually congured and the FlexFit must learn the zero and span ranges of each servo using the signal
from the feedback potentiometers. To zero each servo and set its direction of travel, follow these steps.
• Navigate to Main Menu > Setup > Servo Setup > Zero Calibration.
• For the servo you want to zero, select the correct address and set "Zero Cal" to ENABLE. Optionally, set "Enable All" to
ZERO ALL if you want to zero all servos. This step may take up to 30 seconds; the servo ZERO LED will start to blink.
• Jog the servo all the way to the fully closed position (CW or CCW depending on installation/function).
• The ZERO LED should be either blinking or on continuously. Press and hold the servo ZERO button, and the ZERO LED
will turn off. While still holding down the ZERO button, press the closed direction button (CW or CCW). Hold both buttons
down until the ZERO LED turns back on and remains on. Make sure the correct button was pushed for the Zero direction,
otherwise the servo is not zeroed.
• Release both buttons.
• Repeat the above steps for each servo.
• Exit the Zero Calibration menu.
The steps above tell the FlexFit the zero position and direction of travel for each servo. The following steps tell the FlexFit the
span limits for each servo. Recall the FlexFit uses a resistance signal from the feedback potentiometer to determine servo position.
• Navigate to Main Menu > Setup > Servo Setup > Seek Limits. There will be a scrolling message that states, "Error on
Servo 0". This is normal. Notice that now each servo will be identied by function rather than address.
• For each servo in the daisy chain, set "Seek Limits" to START. Optionally, set "Seek All" to START if you want to seek
limits for all servos. The LCD touchpad will read "Seeking." The servo will move back and forth a couple of times. After
you perform the Seek Limits routine on Servo 0, the scrolling message will change to "Error on Servo 1".
• Repeat the above steps for each servo.
• When you have nished the seek limits process for each servo, the display will scroll "No Errors". From the Seek Limits
screen, scroll down until you see "Closed Limit" and "Open Limit". The numbers you see are the closed and open limits
for each servo (in degrees). All the curve points you enter during commissioning need to be within these limits and must
be a minimum of 2 degrees away from these limits. They should be recorded on the "Boiler Operating Data Sheet" and
referenced during combustion tuning when curve points are entered.
Servo Setup Troubleshooting
If the servos are wired correctly and the instructions above have been followed diligently but a servo is not working, check the
following items:
• Ensure there is not a servo error message on the LCD touchpad.
• Ensure the COMM LED at each servo is ON. If the COMM LED is OFF:
Ensure there is 24 VDC at the display and servo power terminals.
Ensure there is less than 0.75 VDC from servo terminal "IN" to the 24 VDC negative terminals.
If not, start at the FlexFit OUT terminal and determine which servo's OUT terminal is the problem or where the
eld-wiring problem is.
• Ensure the polarity and continuity of the RS485 wiring (terminals Comm + and Comm –) are correct.
• Ensure the scrolling message on every servo indicates the correct servo Function (Sxx). See the list of servo functions
and abbreviations in section "Servo Description and Operation" on page 2-21.
• Ensure the servo address (Axx) matches the servo daisy chain position. If not, change the servo addresses to match the
wiring.
Hint
During initial FlexFit
commissioning, all servos
need to be zeroed. If a
servo is replaced or its
zero position is changed,
you will need to re-zero
only that servo again.
Hint
You will need to reference
the "Closed Limit" and
"Open Limit" later in the
commissioning process.
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