Sentry 200 User manual

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 1 OF 12

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 2 OF 12
TABLE OF CONTENTS
PAGE
1. SAFETY PRECAUTIONS
1.1. Electrical shock 3
2. APPLICATION 3
3. INSTALLATION
3.1. Mount indoor alarm display
3.2. Mount the outdoor junction box
3.3. Install interconnecting cable
3.3.1. Fig wiring diagram
3.4. Test the gauge
3.5. Tether the sensor
3.6. Install control wiring (Model 200C)
3.6.1. Fig terminal blocks
3
3.7. Program the display
3.7.1. Entering programming mode
3.7.2. Programming HIGH level alarm
3.7.3. Programming LOW level alarm
3.7.4. Programming four control relays
(Model 200C)
3.7.5. Programming display brightness
3.7.6. Programming Sensor lengths
3.7.7. Programming display units
3.7.8. Reprogramming and return to display
mode
5
4. OPERATION and TROUBLESHOOTING
4.1. Self calibration
4.2. Troubleshooting table
4.3. Diagnostic mode menu
8
5. SPECIFICATIONS
5.1. Level display
5.2. Sensor
10
6. WARRANTY 11

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 3 OF 12
1. SAFETY PRECAUTIONS
The potential for electrical shock exists whenever water is
present near conductive electrical equipment. Check for
sources of electricity from other nearby devices before working
on this equipment. The low direct current (DC) voltages and
transformer isolation of this instrument pose no danger when
handling or opening the enclosures or connecting the sensor.
Best practice, however, is to disconnect power when working
on this equipment.
2. APPLICATIONS
The Sentry liquid level gauge continuously measures the
water level in cisterns, holding tanks, pump chambers, sumps,
treatment plants, irrigation channels and truck tanks. The
indoor level display indicates the depth of water in feet, meters
or percent. HIGH and LOW level alarm points and an audible
alarm with silence and auto reset can be used to warn of an
alarm condition. A yellow LED indicates when the silence is
activated.
Four relay outputs on the model 200C can be configured to
operate pumps, aerators, remote alarms, security system, auto
dialer or other control applications. Four green LEDs on the
display indicate the relay status.
The sensor rests, vertically, on the bottom of the tank and is
tethered at the top. Sensor cables are terminated in a NEMA
4X junction box, to which customer-supplied cable is
terminated. This cable then terminates at the display. (Fig
3.3.1)
3. INSTALLATION
3.1. Mount the Sentry level display in a dry location, at
a convenient viewing height within 6 feet of a 110VAC
receptacle. Power to the receptacle should be
supplied from a circuit separate from any pump or
equipment that is being monitored or controlled by this
gauge. The supplied screws can be used to mount the

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 4 OF 12
unit. Install screws 3” apart vertically and projecting ¼”
from the surface. Install the AC adapter and plug into
the level display. The LED display will read
indicating that the sensor is not connected.
3.2. Mount the Sentry outdoor weatherproof NEMA 4
junction box to a post or a riser pipe above grade
within nine feet of the top inside of the tank.
3.3. Install a two or three conductor cable between the
junction box and the indoor display. Single sensors
eight feet and less in length use two conductor cable.
Dual sensors or sensors greater than eight feet
require three conductor cable. An 18 gauge cable,
preferably stranded conductors, with an FT4 jacket
(gray PVC) is recommended for most applications.
The sensor power cable(s) are connected to the cable
run inside the junction box. See Fig 3.3.1. The screw
terminal plug is installed on the display end of the
cable and plugged into the display. See Fig 3.6.1
RED +
TOP SENSOR (>8')
FIG 3.3.1
BOTTOM SENSOR
BLACK -
WHITE +
BLACK -
WHITE OR GREEN +
WHITE+
HIGH LEVEL
LOW LEVEL
LEVEL
UP ENTER
DOWN SILENCE
ESC
Aquatic Sentry
CABLE BY CUSTOMER

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 5 OF 12
FIG 3.6.1
T B -
GROUND
BOTTOM
TOP
A - T R 4 4 3 3 2 2 1 1
RELAY
ONE
RECEIVE
TRANSMIT
GROUND
ANALOG
SENSOR TERMINAL RELAY TERMINAL (200C)
3.4. It is good practice to test the operation of the gauge at
this point. Wrapping your hand around the sensor(s)
and moving slowly up will give a reading on the
display at the approximate level of your hand. (The
water in your hand acts as the water that will surround
the sensor when in operation.) Setting the sensor into
a pail of water is another way to test the operation.
The level is displayed in feet, the factory default
setting. This step verifies the integrity of the wiring.
3.5. A single sensor length is a maximum of 8 feet. A top
sensor is used in addition to the bottom sensor for a
total depth of greater than 8 feet up to 16 feet. The top
sensor can be incorporated into the same tube up to
10 feet. After that depth dual sensors are used and a
support leg is used to ensure the top sensor is in
alignment with the bottom sensor. The sensor lengths
may be also be mixed; for example a 12 foot sensor
may be made out of two 6 foot sensors.
Lower the sensor(s) into the water using the tether
rope. DO NOT SUSPEND THE SENSOR FROM THE
POWER CABLE. The sensor is internally weighted
and will rest on the bottom of the tank. For dual
sensor applications mount the support leg to the top
sensor per the enclosed instructions. The tether
rope(s) is tied off to hold the sensor vertical.
3.6. (Model 200C) Run the control wiring to the power
relays. Conductor size maximum is 16 gauge,
preferably stranded. 18 gauge wire is recommended.

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 6 OF 12
The display plug-in screw plug is labeled for relay 1-4
terminals. See Fig 3.6.1.
3.7. Program the display for the required alarm points and
control relay settings referring to the following
instructions and the programming mode menu
supplied separately.
3.7.1.To enter the programming mode hold the
ENTER and ESC buttons down for 5 seconds.
The display will move through the diagnostic
mode and will then display the first item
of the menu, the HIGH LEVEL ALARM.
Scroll through the first level of menu items by
using the UP and DOWN buttons. Select the next
level of each menu item by pressing the ENTER
button. Move back to the previous level of menu
items by pressing the ESC button. Pressing ESC
will not change any values. Press ENTER to
temporarily store each change into memory. The
display will verify the temporary status
when ENTER is pressed.
3.7.2.Program a HIGH LEVEL ALARM by setting the
trip point at the desired depth. As the water level
rises up past that depth, the red LED and the
audio alarm will activate. Set the release point
depth below the trip point to turn the alarm off as
the water level falls and returns to normal. A
release point set above the trip point will be
ignored but the alarm may “hunt”. Set the audio
alarm on or off. If no HIGH LEVEL ALARM is
required, set the trip and release values higher
than the sensor length and the audio to off.
3.7.3.Program a LOW LEVEL ALARM by setting the
trip point at the desired depth. As the water level
falls below that depth the red LED and the audio
alarm will activate. Set the release point depth
above the trip point to turn the alarm off as the
water level rises and returns to normal. A release
point set below the trip point will be ignored but

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
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the alarm may “hunt”. Set the audio alarm on or
off. If no LOW LEVEL ALARM is required, set the
trip and release values to zero and the audio to
off.
3.7.4.(Model 200C Controller). Program any of the four
CONTROL RELAYs by setting the desired action,
or polarity, for the relay – normally open or
normally closed. Set the trip point at the desired
depth. This will activate the relay closed (or open,
depending upon polarity). Set the release point
which activates the relay open (or closed,
depending upon polarity). Setting the release
point above the trip point is a PUMP UP
configuration. Setting the release point below the
trip is a PUMP DOWN configuration. The four
relays can be set independently for any span
throughout the entire range of the sensor to
operate pumps, aerators, low or high level
cutouts, remote alarms, security systems, auto
dialers or other control applications. The relay
status is shown on the front bottom of the display.
Relay 1 status is shown by the right LED. The
position of the LED corresponds to the positions
of the relay wiring terminations on the screw
terminal plug below.
3.7.5.Set the brightness of the LED display to 1, 2, 3
or 4 where 4 is the brightest.
3.7.6.If installing another sensor, other than the
original factory supplied, program the length of
the bottom and top sensor. Lengths are entered
in one foot increments up to 8 feet--the maximum
length of an individual sensor. When two sensors
are used, enter each of their lengths. Example –
a 5 ½ foot sensor would be entered as 6 feet.
3.7.7.If a different display than the factory setting of
depth in feet and decimals of a foot is desired,
set the display units to meters or percent of the
sensor length. Volume will be available in the
future for specific tank configurations.

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 8 OF 12
When in display mode press ENTER to check
which units are being displayed:
Foot (decimals)
Percent of the sensor length
Meters
The display returns to numeric level when
ENTER is released.
3.7.8.Scroll to and press ENTER to return to
the level display. This also reprograms any
temporary value changes that were made and
stored in memory while in programming mode.
4. OPERATION and TROUBLESHOOTING
4.1. Self calibration
This instrument “learns” the characteristics of the tank it is
installed in while it is in use. Readings may be less
accurate when the system is first tested. Once the tank is
in use and has been filled at least ¼ full the system will be
“taught’ and give the best accuracy.

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 9 OF 12
4.2. State Table and Troubleshooting
LED
DISPLAY
HIGH
LEVEL
LOW LEVEL
AUDIO CORRECTIVE ACTION
Display is loading software upon power
up.
Display is not reading sensor; check all
cable connections to sensor.
Check all cable connections to sensor.
Check terminals for correct polarity.
Sensor damaged; replace sensor.
unknown
alphanumeric
value
Unplug power supply and plug back in.
Display will reboot and return to
numeric level display mode.
Check programmed values for
correctness.
Dim
Check the brightness of the display.
See 3.7.5 in this manual.
LED on
unexpected
Check programmed HIGH alarm trip
and release points; see 3.6.2
LED on
unexpected Check programmed LOW alarm trip
and release points; see 3.6.2
Audio on
unexpected
Check programmed HIGH and LOW
alarm .
Verify that release points are set
correctly and the unit is not “hunting”.
See 3.7.2 & 3.7.3
4.3. Diagnostic mode menu
To enter the diagnostic mode press ENTER and ESC at the
same time for 1 second. The display will show ,
indicating it is entering diagnostic mode.
The power level is displayed first. This value is the power level
that the sensor is operating at as a percentage of the maximum
possible signal strength.

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 10 OF 12
The second value is the length of the sensor in 1 ½”
increments.
5. SPECIFICATIONS
5.1. LEVEL DISPLAY
Display – rated for dry locations, –300F to 1000F, four digit
LED, and programmable HIGH and LOW level visual and
audible alarms. Four configurable control relays. Audio
transducer 85db min @ 10 cm. Relays rated 5 Amps at
30VDC.
Power supply 120VAC, 60 Hz, UL listed and CSA certified,
adapting to 12 VDC
5.2. SENSOR
Sensor – Sealed 1 ½” PVC pipe, 3m (9’) SJOOW cable, NEMA
4X weatherproof junction box

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 11 OF 12
6. WARRANTY
Aquatic Sentry Controls Inc. warrants that this product is free from
defects in materials and workmanship under normal use and service
for a period of one year from the date of purchase by the initial owner.
Aquatic Sentry shall be responsible only for actual loss or damage
suffered and then only to the extent of Aquatic Sentry’s invoiced price.
Within the warranty period we shall repair, refurbish or replace, at our
option, such products or components, which are returned to us with
shipping charges prepaid, and which are determined by us to be
defective. This warranty will not apply to any product or part thereof
which has been subject to misuse, negligence, or accident; or
misapplied; or modified; or repaired by unauthorized persons; or
improperly installed. The provisions of the above warranty are our sole
obligation and exclude all other remedies or warranties, expressed or
implied, including warranties of merchantability and fitness for a
particular purpose, whether or not purposes or specifications are
described herein. We further disclaim any responsibility whatsoever to
the customer, or to any person, for injury to person, damage to, or loss
of property or value caused by any product, regardless of whether the
defect is warrantable or whether the product has been subjected to
misuse, negligence, accident; or modified or repaired by unauthorized
persons; or improperly installed.
Under no circumstances shall the company be liable for any
incidental, consequential or special damages, loss or expenses arising
from the use of this product, or in connection with the use of, or
inability to use, our product for any other purpose whatsoever.
Aquatic Sentry products or parts thereof assumed to be defective by
the purchaser within the stipulated warranty period should be returned
to the seller or local distributor for evaluation and service. If deemed
necessary, the seller or distributor shall contact Aquatic Sentry
Controls Inc. for a Returned Materials Authorization and then return
the item for direct factory evaluation, service or replacement. No
material may be returned to Aquatic Sentry Controls Inc. without
proper factory authorization.

Sentry LIQUID LEVEL GAUGE MODEL 200 or 200C
OWNER MANUAL
REV 1.7
SEPT08
PAGE 12 OF 12
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