TROUBLESHOOTING
7
Indicators:
1) “CAL” green LED -
Its status describes the “calibration”
condition of the MK-2. Illumination indicates that the sensor
has successfully been calibrated. Flashing indicates that a
calibration is in process.
2) “SEN” Red LED -
Their status describes how “sensitive” the
MK-2 will be to the target material. The particular LED illu-
minated indicates which sensitivity selection has been
made.
3) “DET” yellow LED
- Its status describes the “detection/
sensing” condition of the MK-2. Illumination indicates that
the amount of capacitance established by the “sensitivity
selection” has been detected. Its status is not affected by
the time delay setting.
4) “OPR” Red LED -
Its status describes the “operate/output”
condition of the MK-2. Illumination indicates that the relay
output is in the “operate/material sensed” condition. Its state
is influenced by the time delay setting but not by the fail-safe
setting.
5)
Material Presence "Y" Red LED
- Its status matches the
indication of the "OPR" Red LED. That is, illumination indi-
cates that the relay output is in the "operate/material
sensed" condition. This LED can be viewed externally
through the lens in the top of the cover (ordinary location
units only). Illumination also indicates that power is present
at the MK-2.
6)
Material Presence "N" Green LED
- Its status is opposite
the indication of the Material Presence "Y" Red Led and the
"OPR" Red LED. That is, illumination indicates that the
relay output is in the "non-operate/no material sensed" con-
dition. This LED can be viewed externally through the lens
in the top of the cover (ordinary location units only). Illumi-
nation also indicates that power is present at the MK-2.
Initialization/Self-Verification Mode:
The microcontroller-based electronics will flash the Material
Presence "Y" Red and "N" Green LEDs in either of the following
situations:
1)
Power-up initialization- Whenever power is first applied, the
MK-2 spends roughly two (2) seconds to settle into a normal
state. During this time, the LEDs will flash.
2)
Self-Verification error- During normal operation, the MK-2
continually checks itself for proper processing. If an abnor-
mal condition is detected, the MK-2 will force the relay into
the state related to the "fail-safe" selection and will flash the
Material Presence LEDs.
Calibration Procedure:
1)
Select the fail-safe setting appropriate for the application.
2)
Set the time delay desired, from .25 to 15 seconds.
3)
Select sensitivity 1, 2, 3 or 4. Figure 10 provides a guide for
initial setup. This may have to be re-selected depending
upon the actual application characteristics.
4)
Ensure the probe is not submerged in the material.
5)
Press and release the “CAL” button. The green “CAL” LED
will flash, then remain illuminated, indicating a successful
and complete calibration.
PRObLEM: Sensor does not detect material.
CAuSE/SOLuTION:
1)
Verify that power is applied to the sensor. One of four
“SEN” indicators should always be lit.
2)
Verify condition of “CAL” LED when material is not
present. If not lit, recalibrate the sensor.
3)
Verify continuity between probe mount and vessel wall.
If poor continuity exists, connect a ground wire between
the housing and vessel wall.
4)
Verify sensitivity setting. Move sensitivity selection to a
lower numbered setting, therefore making the probe
more sensitive to “difficult to sense” materials.
5)
Verify probe coverage when sensing is expected. The
sensor is not designed to be “tip sensitive”. Permit sig-
nificant probe coverage before expecting material
sensing.
6)
Verify connection of the electronic module to the probe.
7)
Verify circuitry operation by using the TEST function, as
described in this manual. If improper operation per-
sists, consult factory.
PRObLEM: Sensor remains in “DET” mode even when
material is absent.
CAuSE/SOLuTION:
1)
Verify the active probe is not in direct contact with any
internal vessel structure. If so, reposition sensor.
2)
Verify sensitivity setting. Move sensitivity selection to a
higher numbered setting, therefore making the probe
less sensitive to “easy to sense” materials. Sensitivity
#4 is appropriate for highly conductive materials (i.e.
water based products).
3)
Examine build-up on probe surface. Clean probe if
necessary.
4)
Only as last resort, recalibrate sensor. If improper
operation persists, consult factory.
PRObLEM: Output contact perform opposite of
designations (N/O, N/C).
CAuSE/SOLuTION:
1)
Designations on PCB relate to relay status when in
“Fail-safe Low” mode and when no material is sensed.
If “Fail-safe High” mode is used, the designations are
reversed. Swap the wire terminations of N/O and N/C if
necessary.
PRObLEM: Sensor does not respond to any switch
activation.
CAuSE/SOLuTION:
1)
Press and release reset switch located on the right side
of the control panel. The switch can be accessed
through a small hole in the label and will re-boot inter-
nal software. Wait approximately 2 seconds for soft-
ware to reset. If improper operation persists, consult
factory.
