User Manual & Datasheet V 2.1
the Evaluation Unit.A set of single change-over po-
tential free relay contacts rated at 6 amps, 230 V
AC for non-inductive loads are provided for the pur-
pose.Required contacts should be selected after re-
ferring enclosed diagram that show the dependence
of relay operation/indication on fail safe mode and
level.
•
FAIL SAFE OPERATION
- Instrument operation
is supposed to be fail safe if alarm condition is sig-
naled by the relay in the de-energized condition.This
necessitates a change in the state of the relay when
the instrument is used for high or low alarm as the
conditions are opposite.Fail safe select switch is pro-
vided just for this purpose.When the instrument is
used for high level alarm the switch should be in
fail safe high position whereas for low level alarm it
should be in fail safe low position.It should be noted
that the output contacts will change positions as
per fail safe selection.Connections to external alarms
should made accordingly.Red and Green LED’s indi-
cate Alarm and Normal operation.Red LED glows
when the relay in de-energized position.
12
Calibration
Calibration controls are accessible after opening the
Evaluation Unit cover.
A. SLA 122 / 222
- Calibration is done with the
probe uncovered.Clearance between the probe and mate-
rial should be at least 100 mm.
•
Make all connections as per connection diagram af-
ter reading the instructions under connection cap-
tion, and switch on the mains.
•
Throw the fail safe selection switch to fail safe ’HI’
position.
•
Throw the range selection switch to range ’I’ posi-
tion.
Calibration procedure for Fail-Safe High mode
-
a)Turn ’sensitivity adj’.pot anti-clockwise to the
extreme left position.Red LED goes ON.
b)Turn pot clockwise until Green LED goes ON.
c)If the Green LED does not glow even though the
pot is turned fully clockwise, select next higher range
i.e.range II.If green LED goes ON go through to next
step.If green LED does not go ON select next higher
range i.e. range III.LED would definitely go ON.
d)Turn sensitivity pot anticlockwise until red LED
goes ON.Again turn sensitivity pot slowly clockwise until
green LED just goes ON.
e)From this accurate switch point position, turn the
pot a few degrees clockwise (Green LED remains ON),
thereby setting the sensitivity to as table switching
position.
f)The instrument is now calibrated.If it be possible to
vary the material level in the vicinity of the switch point,
the correctness of calibration can be confirmed.
Calibration procedure for Fail-Safe Low mode
-
a) After following similar instructions 4 (a) to (g)
throw the fail safe select switch ’FSS’ to fail safe ’LO’
position.
b) The instrument is now calibrated.If it be possi-
ble to vary the material level in the vicinity of the switch
point, the correctness of calibration can be confirmed.
B. SLA 322 / 622
- Rotate time delay pot fully
anti-clockwise (minimum delay position), then proceed
as per calibration instructions for SLA 122 /222 (Sr.No.
1 to 5).
Switching delay adjustment :
•
Select delay mode by throwing the mode select
switch to appropriate position-
Position ‘S’ gives delay for probe uncovered condi-
tion.
Position ‘T’ gives delay for probe covered condition.
•
Set time delay approx. between 0.5 to 10/20 secs.
by turning the time delay pot clockwise.
C. SLA 722
- These models have built-in pump control
logic.The switching hysterisis is continuously adjustable
over the full range (wide differential).
Calibration procedure starts after filling the tank up to
upper level point.
•
Throw the fail safe select switch to fail safe ’HI’.
•
Throw the calibration switch ’CAL’ to position ’CA’
position.
•
Throw the range selection switch to position ’I’.
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Calibration procedure For
Fail-Safe High
1. Rotate pot ’
∆
S’ anti-clock wise to its extreme posi-
tion.
2. Rotate pot for ’CA’ clockwise to its extreme posi-
tion.Green LED goes ON.Go to step 4.
3. If green LED does not go ON, select next higher
range i.e. range II.If Green LED does not go ON
select next higher range i.e. range III.Now Green
LED will definitely glow.If it does not, contact us.
Sapcon Instruments Pvt.Ltd.
R
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