Master / Slave Alignment
A Slave Tracker not having sensor feedback like a Master may consistently run ahead or behind the Master. This could be due to slight differences in the motors, gearing lubrication, mechanical wear on the tracking system.
If the variance is not consistent then there could be motor, gears or slew problems and this procedure should not be used.
If the Slave Tracker is behind the Master (Azimuth)
To obtain maximum accuracy and kW production, the Slave should be calibrated to align with the Master at solar noon. If the Slave is behind the Master and hasn’t reached 180 degrees (in the Northern Hemisphere) then the Minimum Limit Switch should be adjusted so that the starting position in the morning is ahead by the same amount so that the positions of the Master & Slave converge at noon.
If the Slave Tracker is ahead of the Master (Azimuth)
Conversely if the variance of the Slave has reached more than180 degrees then the Minimum Limit Switch should be adjusted so that the starting position in the morning is behind by the same amount.
It is possible to achieve the same results by adjusting the Master Limit Switch in the opposite direction but this will throw off the Minimum Limit Switch calibration so will need a correction (see correction)The Slave adjustment is preferred.
- Set the Stow position for all trackers (FI12 AX1stow or FI13 AX2stow) to 180 deg. depending on which axis you are calibrating.
- Observe the difference in the Slave Tracker.
- Adjust the Minimum Limit Switch as described above.
- Put the subject Master Tracker into Manual Control (ie. X101 AX1softAM_01_1 = OFF).
- Drive (ie. X1017 AX1runDir_01_1 = ON) the motor East to the Minimum Limit Switch until its stops and recalibrates to the defined value (FI4 AX1calibrateLS or FI5 AX2calibrateLS)
- The Slave Tracker should reach the Limit Switch at a different time than the Master.
- Put the subject Master Tracker into Auto Control (ie. X101 AX1softAM_01_1 = ON).
- When the Master & Slave Trackers reach solar noon they should be in alignment. If not repeat the procedure.
This procedure is the same except the Stow position should be 45 degrees.
Calibrate the same.