Labkotec SET/DM3AL Specification sheet
SET/DM3AL D26052AE-2
Operation and Installation Manual
All rights reserved. Copyright © 2019, Labkotec Oy
2(5)
SYMBOLS
To be considered in installations in
potentially explosive atmospheres.
Warning / Attention
1. YLEISTÄ
SET/DM3AL is a level switch sensor, which is to be
connected to analogical and digital SET control
units of Labkotec. Operating principle of the sensor
is based on the measurement of electric conduct-
ance.
SET/DM3AL sensor is suitable to be used as a
level alarm device for liquids. It can be used to
indicate the interface between oil and water or
water and air. Typical applications of the sensor
include oil and grease separators.
The SET/DM3AL has been certified according to
the ATEX Directive in equipment category 1 and it
can be installed in potentially explosive atmos-
pheres in zoned areas 0, 1, and 2.
SET/DM3AL replace SET DM/3 sensor and it can
be installed directly in its place.
Figure 1.
Dimensional drawing of the SET/DM3AL-sensor
Figure 2.
Application: Oil alarm for the oil separator
2. TECHNICAL DATA
Control unit:
SET-1000, SET-2000 –control
units by Labkotec Oy
Signal
Operating voltage
Analogical 3 mA/10 mA
8 V…16 V (DC)
Cable:
Shielded oil-proof cable 2 x 0.75
mm2. Standard length 5 m. Other
lengths optional. The max. length
of the fixed cable is 15 m. Can be
extended with a shielded cable.
The recommended maximum
cable loop resistance is 75 Ω.
Material:
PVC (black), AISI 316, NBR, PA
Temperature range:
Operation: 0…+60 °C
Safety: -30…+60 °C
EMC
Emissions
Immunity
IEC/EN 61000-6-3
IEC/EN 61000-6-2
IP-classification:
IP68
Ex-classification:
Special conditions (X)
ATEX
IECEx
II 1 G Ex ia IIA T5 Ga
(Ta -30…+60°C)
EESF 19 ATEX 004X
IECEx EESF 19.0004X
Electrical
parameters:
Ui = 16 V Ii = 80 mA
Pi = 400 mW
Ci = 3,5 nF Li = 85 μH
Operating principle:
Conductance
Manufacturing
year:
Please see the serial
number on the type
plate.
x xxx x xxxxx xx YY x
where YY = manufacturing year
(e.g.. 19=2019)
The sensor may be installed in potentially explosive
atmospheres of zones 0, 1, and 2 with the following
special conditions (X):
–The ambient temperature is –30…+60°C.
–The risk of electrostatic charge must be observed!
Standards to be considered in the installation:
IEC/EN 60079-25 Intrinsically-safe electrical systems "i",
and/or IEC/EN 60079-14 Electrical installations in hazardous
areas. If the cabling is voltage-tested, the sensor must be
disconnected from the system.
SET/DM3AL D26052AE-2
Operation and Installation Manual
All rights reserved. Copyright © 2019, Labkotec Oy
3(5)
3. CONNECTIONS AND INSTALLATION
The SET/DM3AL sensor is equipped with a shield-
ed 2-wire cable. The numbered wires 1 and 2 of
the cable are connected to the corresponding con-
nectors (1 = +, 2 = - ) in the control unit. Unnum-
bered wire is connected to the cable shield. Always
check the connections from the installation and
operation manual of the control unit as well.
In figure 3 the connection example 1; a LJB2-78-
83 junction box has been used to connect the ca-
bling to the equipotential bonding.
In figure 3 connection examples 2 and 3; equipo-
tential bonding is not available. The shield is con-
nected to the appropriate connector in the supply
device.
In these kinds of arrangements, it must be
ensured that the electrostatic charges do not
cause a hazard. Make sure in the installation that
the device and cabling are not close to any strong
current or other installations, and that they are not
exposed to any strong stream flows, mechanical
abrasions, or impacts.
The cable may be shortened or extended with a
junction box, if necessary. The sensor may be
installed by hanging it from its cable (upper limit
alarm) or immersed in the liquid to be measured
(lower limit or interface alarms).
The example in figure 3 shows an oil separator
application in which the switch data is received
when the upper electrode is covered in oil i.e. is no
longer immersed in the conductive liquid.
4. OPERATION
This chapter provides a general description of the
operation of the oil alarm in different situations. For
a more detailed description, please refer to the
manual of the control unit in use.
Normal
mode
The SET/DM3AL oil level sensor is entire-
ly immersed in water.
The indicator lights are off.
The relays are energized.
Oil
cham-
ber full
The SET/DM3AL sensor is immersed in
oil. (The sensor does not issue an alarm
before the upper electrode is covered in
oil. The alarm is issued at the latest when
the entire sensor is immersed in oil.)
The Oil chamber is full indicator lights up.
The buzzer sounds
The relays are de-energized.
(Please note. A similar alarm is issued
when the SET/ DM3AL sensor is in the
air.)
Once the alarm is off, the indicator lights
switch off, the buzzer stops, and the relays
are energized.
Fault
alarm
The sensor is broken, there is a sensor
cable break or a short circuit, or the sen-
sor signal is not recognized (digital sys-
tem).
The sensor circuit’s Fault indicator is on.
The buzzer sounds.
The relays are de-energized.
Figure 3. Installation example in an oil separator.
SET/DM3AL D26052AE-2
Operation and Installation Manual
All rights reserved. Copyright © 2019, Labkotec Oy
4(5)
5. OPERATION TEST
Always check the correct operation of the alarm
after the installation and after making the connec-
tions. You should also check the operation every
time the separator is emptied or at least once a
year.
Testing
the ope-
ration
1. Immerse the sensor entirely in
water. The device should be in
normal mode (see chapter 4).
2. Lift the sensor in the air or im-
merse it in oil. The “Oil chamber
full” alarm should be issued (see
Chapter 4).
3. Put the sensor back into water.
The alarm should stop after a
while. Clean the sensor before
installing it into the separator.
If the sensor does not function as described, check
the device settings from the control unit manual or
contact the representative of the manufacturer
6. SERVICE AND REPAIR
The sensor must be cleaned and tested when
emptying the storage chamber and in connection
with the annual maintenance. A mild detergent
(e.g. washing-up liquid) and a scrubbing brush can
be used for cleaning the sensor, if necessary.
During maintenance procedures (such
as servicing the oil/fuel separator sys-
tems), the sensor should not be lifted out of
the separator tank or installed back until
there is water in the tank.
The instructions concerning the
inspection and maintenance of Ex
equipment contained in the standards IEC/EN
60079-17 and IEC/EN 60079-19 should be ob-
served when executing service, inspection, or
repair procedures
In fault situation check the cabling and connections
of possible short-circuits or interruptions, then, if
necessary, measure the sensor current and com-
pare it with current values below.
Attention! If the sensor is located in an explosive
atmosphere, the multimeter must be Exi-approved!
Sensor in the water:
3 –4 mA
Sensor in the air:
9 –11 mA
Sensor in the oil or grease:
9 –11 mA
Also measure the output voltage of control unit. It
is typically between 10-12 V with Labkotec Oy’s
SET-control units. See details from the manual of
the control unit.
In case of queries, please contact Labkotec Oy’s
service.
7. SET/DM3AL –and SET/DM3DL –SENSORS
SET/DM3AL –sensor is designed to use with ana-
logical SET-control units, such as e.g. SET-1000,
OilSET-1000, SET-2000, SET-2000 Hi Level/Oil.
SET/DM3DL -sensor is primarily designed to use
with control units that communicate digitally, such
as e.g. LevelSET S.
Visually the difference of SET/DM3AL- and
SET/DM3DL –sensors is that SET/DM3AL sensor
body is black and SET/DM3DL sensor body is
grey.
This operation and installation manual applies only
to SET/DM3AL-sensor.
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