Software Calibration, Electrical Slide Systems - Johnson Controls SABROE Unisab III Control Engineering Manual

During normal operation the red LED is flashing rather slowly. The green LED is switched on
constantly when the transmitter is in 100% position whereas it flashes quickly when the
transmitter is in 0% position.
Calibration is carried out as follows:
1. Apply supply voltage minimum five minutes before calibration.
2. Press the calibration button for five seconds to get the transmitter in calibration
mode. The red LED will change from normal flashing to OFF.
3. Decrease capacity to minimum and press the calibration button once. The red LED will
turn ON. After a while, the red LED will turn OFF again indicating that the position
transmitter is ready for 100% calibration.
4. Increase capacity to maximum and press the calibration button twice. The red LED
will start flashing quickly. After a while, the red LED will change to normal flash rate
indicating that calibration has been completed.
Points 3 or 4 or both may be ignored. Pressing the calibration button for five seconds in cali-
bration mode will bring the transmitter back to normal operation mode.
The 4-20 mA signal from the transmitter is permanently available. However, during calibra-
tion the signal is based on the default calibration values so it will neither show 0% at mini-
mum capacity nor 100% at maximum capacity.
Note: It is possible to return to the default calibration values by pressing the calibration but-
ton down for minimum twenty seconds. However, it is the default values of the transmitter
manufacturer which are reset. These values may differ very much from the correct values for
the compressor. Reset is indicated by the red and green LED flashing briefly a couple of times.

7.6.3 Software calibration, electrical slide systems

When the capacity position transmitter has been adjusted (see subsection 7.6.2. Transmitter
adjustment) capacity must be further adjusted. It is recommended to introduce a calculation
offset of 2% to ensure that the slide does not collide with the end stops. Collisions will reduce
slide motor service life etc.
Select Setup/Configuration/Calibrate/Position.
Decrease capacity to minimum. Change Cap. Zero Adjustm. so that a value of -2.0% is dis-
played for Cap Slide Position.
If capacity is e.g. 1.5 % and Cap. Zero Adjustm. = 0.0% select Cap. Zero Adjustm. = - 3.5%.
Increase capacity to maximum. Change Cap. 100% Adjustm. so that a value of 102.0 % is
displayed for Capacity. If capacity is e.g. 100.3% and Cap. 100% Adjustm. = 0.0% select
Cap. 100% Adjustm.= 1.7 %.
Engineering manual - Unisab III 1.10
250/319
Calibration
001930 en 2014.09