Aquametrix 2200P pH Analyzer/Controller User Manual - Manual (Page 27)

Model 2200P Page 25
these steps do not solve the problem it may be necessary to replace the power
supply board. See Section 9.4 below.
9.2.3 Should your process control element e.g. pump, valve or alarm not be activating,
check that the correct power is supplied to the "floating” relay contacts, jumped over
from the line voltage terminals or perhaps from a separate breaker or DC supply.
Use the TEST menu feature to simulate the input values to observe the switching
points.
Check that your process control elements can function independently of the 2200P.
Next check with a test light or an Ohmmeter (power off to the relay contacts, wires
to the control elements disconnected) that the contacts of the respective relay are
making contact when actuated. If a relay is malfunctioning, it may be necessary to
change it. See Section 9.5.
9.2.4 If the process value seems wrong, clean the probe as described in the probe
manual. Inspect the probe, wire and interconnections. Open the inner door and
ensure that the two jumpers J42 are in the correct position for the probe used and
the probe wires are correctly and firmly connected. See Sections 3.5 and 3.6. Now
place the probe into a 7 pH buffer. Rinse, and place it into a 10 pH or 4 pH buffer
while observing the panel meter. If the values are close, re-calibrate and resume
operation. Should there be a major discrepancy, bring the probe and buffers to the
2200P, connect directly to the 2200P and repeat the procedure. If that does not
solve the problem, replace the probe.
9.2.5
To find out whether the problem is in the sensor, or in the analyzer, use the self-
testing features. Do not disconnect the sensor. Proceed as follows:
a) Move the slide switch S40, if you are using an AquaMetrix differential probe
(P60 series), or S41 if you are using a conventional probe (P500 series), from
position “ON LINE” to position “TEST”. Turn the pH simulation potentiometer
R65 from end to end. The display should change between 0.00 and 14.00 pH.
If this is the case, the analyzer is in order, and the problem is in the sensor.
Otherwise the problem is in the analyzer.
b) To check the temperature channel move the slide switch S41 from position “ON
LINE” to position TEST. Go to the TEMPERATURE Menu item. The display
should be 25.0°C ± 0.1°C, in which case the analyzer is in order and the
problem is in the sensor. Otherwise the problem is in the analyzer.
For normal operation both slide switches S40 and S41 must be in
“ON LINE” position.
9.3 “Escape” Procedure
9.3.1 If the instrument appears to be "DEAD", for example not responding to the buttons,
or not performing on line measurement and control, always try the reset feature
first, as described in 6.4.1.
9.3.2 a) The "ESCAPE" procedure is to be used normally at the factory only, when the
unit is powered with a new MCU. As a result, the internal non-volatile memory
(EEPROM) is "FORMATTED" and the factory values are loaded into it.
b) The "ESCAPE" procedure is to be used if a unit is serviced for a new MCU
insertion, in case where the MCU was not calibrated at Water Analytics, or in