Techtrol VLC Quick start guide

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1
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To get best intrinsic value of every Techtrol product it
should be installed, maintained properly and used within
its specified limits. It will help to extend the working life
of your instrument.
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1. Examine the switch and ensure that it is in accordance
with required specification.
2. Visually examine the instrument for any damages or
breakage.
3. Check and record the model number and serial
number for future reference.
Vertical Level Control for Boile
r
–
‘
VLC
’
Fig1Fig2Dimensions
(Approx)
(Approx)
100
CCD±1
125
142
(Approx)
(A pprox)
250
135
CONTROL
RANGE=
150±2(APPROX)
L1
L2
L3
L
01) Switch enclosure
03) Conduit conn
04) Gasket
05)
Chamber flange06)
Switch flange
07) Steam side conn
09) Chamber
10)
11)
Chamber end cap
12)
Float stem
Float
13)
14)
Airbreak switch assy
Bolts & nuts
02) Base
08) Water side conn
15) Plug
01
03
13
04
05
06
14
09
11
12
10
07
02
Primary
magnet
Secondary
magnet
Airbreak
switch
Float
Stem
08
15
INSTALLATION & OPERATIONAL MANUAL
Unpacking:

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2
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1. Ensure that float connected to stem is properly tightened. If not, tighten it.
2. Ensure other fasteners / screws have not loosened in transit. Tighten them adequately, if found
loose.
3. Open the enclosure cover. Switch assembly are fitted on the seal pipe.
4. Select continuity range on multimeter and connect its probes to `P' and `NO' contact of level
switch
5. Move the float manually upwards from its `Normal condition' to `Alarm condition' and ensure
that `NO' contacts become `NC' by observing continuity on the multimeter.
6. Similarly check all the contacts.
1. Select suitable location on the tank where the
vibrations are minimum.
2. The switch is installed vertically from top & can
be mounted internally fig 3 or externally as
shown fig.4.
3. External mounting is resorted to, where space is
limited or mechanical devices like stirrers
operate within the tank. Besides, in applications
like boilers, reaction kettles etc. with external
mounting, switch can be isolated for regular
servicing.
4. Ensure that process connection of level switch
should match with those on tank.
5. Ensure in case of externally mounted version CC
distance of external cage match with those on
tank.
6. Provide separate Isolation valve on tank for safety
& removal of Level switch for repairs/maintenance.
7. Ensure mounting nozzle length & inside diameter
must be sized correctly to allow for switch
actuation at desired level.
8. Provide suitable gasket between the flanges and
appropriate thread sealant between threads
before bolting / tightening, to ensure zero leakage
through joints.
9. Ensure that stem does not get bend during
installation.
Fig3‐Internalmountingontan
k
Fig4‐ExternalmountingonChamber
Tank
Proces Conn.
Stillwell
(Customer's scope)
Pressure
OPEN
SHUT
Boiler/
Vessel
OPEN
SHUT
Isolation
Valves
External
Chamber
Installation:
Pre-Installation Check:

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3
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The switch can be wired directly " to make or break
electrical circuits " of burners, contacts being rated
for 5A at 230 VAC can be directly wired to control
devices viz. Solenoid valve or pumps, through a
PVC cable of 2.5 mm2.
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1. Ensure that during operation, operating temperature and pressure remains within specified
limits.
2. Do not exceed the load limits (VA ratings) of switch.
In case float is punctured or stem bend may be
due to sudden change in float movement, replace
it as per steps given below
1. Take out VLC from the chamber/ tank.
2. Float and stem is screwed to the flange
connection with adaptor.
3. Unscrew the adaptor and you can remove the
stem out.
4. Take the new stem. Ensure that the stopper is
fixed at 85 mm from top of the actuator end.
5. Now insert the actuator through the insert
provided on the flange and screw the adaptor
to the flange. (Refer adjacent figure)
6. In case only float is punctured, unscrew the
float from stem and remove it. Replace new
float by screwing it to stem.
P
NO
NC
L3
P
P
NO
NC
P
P
NO
NC
P
L2
L1
Actuator
FloatStem
Stopper
Adaptor
Float
(Primary Magnet)
85
Fig5
Fig6
Replacement of Float & Stem:
Operation:
Termination:

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4
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Number of switches are mounted on either side of the seal pipe.
1. Each switch is fixed on guide rod pipe through
a screw. They are set in factory at required
level set point.
2. The switch can be adjusted on site by
loosening the screw and moving it in
downward or upward for required distance.
Now tighten the screw.
3. Refer values of A, B & C in fig 9 for minimum
distances that can be set.
1. Periodic inspection is necessary to keep your level switches in good working condition.
Switch
(Low)
Switch
(High))
Guide
Rod
Seal
Pipe
Enclosure
Base
Fig7
Fig8
Screw
Fig9
100
A
C(Control
Range) =
150±2 m m
Control
Range =
150±2 (Approx.)
CCD
125
B
B
A(min)=100mm
B(min)=50mm
Adjustment of switch position: (fig 7 & 8)
Periodic Maintenance:

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5
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2. Periodically, during shut down: remove the switch & wipe the float to remove deposits of scaling
formed on it.
3. Vibration may sometimes cause terminal screws to get loose. Check all terminal connections and
be certain that screws are tight.
4. Ensure that contacts of switching mechanism are not pitted / oxidized due to sparking.
5. Switches must be cleaned frequently, if the liquid has high viscosity or contain floating
material.
6. Disconnect device from the supply, before opening, to prevent ignition in hazardous
atmosphere.
7. Be sure the switch enclosure cover is always in place on the enclosure.
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SL Problem Cause Solution
1 No switching
signal from level
control.
a. Switch damaged due to load
more than its rating.
b. Terminal contacts oxidized /
pitted due to sparking.
c. Float punctured or stem bend
d. Wiring terminals loose.
e. Improper wiring.
f. Liquid Sp. gr < 0.8.
a. Replace switch.
b. Clean contacts.
c. Replace float /stem
d. Tighten terminal contacts.
e. Wiring as per wiring diagram.
f. Consult factory.
2 Switch
chattering. a. Loose wiring at terminals. a. Tighten the terminals.
3 Switch not
operating or not
operating at
desired level.
a. Excessive deposition on float
surface due to dirt in liquid.
b. Vibration may cause damage to
wiring connections.
a. Clean the surface where
deposition has taken place.
b. Avoid vibrations by providing
dampers.
MAN
/
VLC
/
REV00
/
03‐2020
Troubleshooting: 