S-SM-11-01e / 2
Sentry operation
Press the ‘test’ button.
All the LED’s will briefly light in the initial lamp test mode.
The yellow LED corresponding to zone 1 will then light and the protection level for zone 1 will be
shown by two LED’s on the protection level display and the millivolt reading will be indicated on the
LCD.
After a few seconds the yellow Zone 2 LED will illuminate and the protection level LEDs and LCD will
show the protection level within this zone.
After a few seconds more the yellow Zone 3 LED will illuminate and the protection level LEDs and
LCD will show the protection level within this zone.
The cycle will then recommence with the Zone 1 display.
Note. If only two zones have been specified at the time of ordering then zone 3 will not be
displayed.
In order to conserve battery life the unit
operates for 30 seconds and then powers down.
In case of low battery voltage a ‘Lo Bat’ indication will appear in the top left corner of the LCD.
The
Sentry
LED’s indicate the current level of cathodic protection.
Providing that the
Sentry
has been set up for the correct
material
being protected then the green
LED indication shows that the material is protected from corrosion. Red LED indication warns of
under protection or over protection. Under protection indicates corrosion can take place. Over
protection can also indicate that corrosion or other problems are occurring.
Extreme over or under protection is indicated by a single flashing red LED.
An extreme over protection indication may also be caused by faulty connection to the electrode or
the electrode being out of the water.
For a particular zone, a reference electrode must be connected to the corresponding terminal on
the
Sentry
mutizone
and it must be in contact with sea water. Only then will the unit correctly indicate the
cathodic protection level.
Sentry calibration and options
The
Sentry
has been calibrated prior to dispatch from the factory and needs no further adjustment.
Three material settings are available on this model for correctly displaying the protection level of
Aluminum, Steel or Bronze. This is set at the factory.
Sentry fault finding
In order to test the operation of the
Sentry
press ‘test’ and check that all lights illuminate for about
one second and that the LCD displays the material being monitored. If this does not happen check
that the batteries are not flat and that they are correctly installed.
Disconnect the electrode wire from terminal ‘1’ and check that the top red led flashes and that the
LCD reads between -1200 and -1300mV when zone 1 is being displayed. Repeat this for electrodes
2 and 3.
Link terminals ‘E’ and ‘1’ and check that the LCD reads between -10 and +-10mV when zone 1 is
being displayed. Repeat this for electrodes 2 and 3.
.
Reconnect terminal ‘E’ to the hull and terminals ‘1’, ‘2’ and ‘3’ to their individual electrodes.
