Ver 5.0 pH Mini Controller Installation Guide (September 2020) Copyright©2020 Autogrow Systems Limited 10
Fault Finding
•Unit is completely dead –i.e. no display, no power light, no outputs. Check
the power pack is functioning, (by measuring with a voltmeter if possible),
is plugged in, switched on and properly connected to the controller. If unit
still fails to function, the probability is the internal 4A fuse (20mm x 5mm
miniature glass fuse) may have blown. Most likely cause is that wires
connecting to the pumps have touched together and shorted out. To fix this
it is important to clear the fault first. Inspect all wiring and ensure all wires
are well insulated right to the point where they enter the terminal block.
Then replace the fuse with a genuine 4A fuse. DO NOT ATTACH WIRE OR
ALUMINIUM FOIL ACROSS IT.
•Cannot calibrate pH. - Ensure your calibration solution is new and has been
stored at room temperature. NEVER reuse calibration solution. If the
calibration solution is fine, you will need to replace the pH probe. Any pH
probe with a standard BNC connector will do.
•pH fails to dose - Ensure that the controller is set for raise or lower to match
the solution used. i.e. if you are using acid (pH down), set the controller to
pH lower and ensure the pump is connected to the pH lower output.
•pH overdoses - Check that the controller is set for pH raise or lower as
described in 4 above. Also, check that the dose time is not excessive. Each
dose should change the pH by about 0.1pH
Specification
•2 outputs for pH raise and pH lower
•Output voltage same as supplied voltage 12V to 24V AC or DC, normally 24V DC supplied (Please
contact Autogrow before using an AC power supply)
•pH resolution and accuracy –0.1 pH
•pH measurement range 2pH to 12pH
•Operating temperature range 0-45oC, 32-110oF (and not in direct sunlight)
•Dosing fail safe shut-off if pH below 4.5pH or above 8.0pH
