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D2133_01_04 CN5082 SEM110 User Guide
1.0 GENERAL
The SEM110 series are high performance two wire (4 to 2 0) mA
transmitters designed to accept most standard indus trial temperature,
thermocouple, slide wire and variable resistance se nsors which operate
over most common ranges. Automatic thermocouple cold junction
compensation is provided on thermocouple versions where the output is
directly referenced to the mV input, allowing linearisa tion to be carried out
by the loop monitoring instrumentation, if required. The de vice is potted
inside a plastic enclosure, suitable for head mounting int o any DIN style
enclosure. Screw terminals are provided for wire connecti ons. Trim
potentiometers are provided to allow calibration adjustme nts.
2.0 SEM110 SPECIFICATION @ 20 ºC
Part Number Input Type
SEM110TC Isolated (Un-grounded) Thermocouple types
K,T,J,R,S,N
SEM110P PT100, PT10, PT1000
SEM110W Slide Wire
SEM110Z Variable resistance
SEM110D Differential PT100
OUTPUT (4 to 20) mA two wire (Max 30 mA)
SUPPLY VOLTAGE (10 to 45) V DC reverse connection protected.
30 VDC Max I.S. version
AMBIENT TEMP (0 to 70) ºC operation
(-40 to 100) ºC storage
AMBIENT HUMIDITY (0 to 95) % (non condensing)
CONNECTION Screw Terminal
Recommended cable size 2.5 mm sq.
ZERO DRIFT ±2 µA/ºC
SPAN DRIFT ±0.01 %/ºC
LOOP RESISTANCE 700 R Max (24 V)
EMC Conforms to BS EN 61326
3.0 INSTALLATION
3.1 Mechanical
The transmitter is mounted using two 4.5 mm diameter holes, on standard
33 mm fixing centres. This transmitter has been speci fically designed to
be mounted inside a DIN standard probe head, which mus t provide
adequate protection to moisture, corrosive atmospher es etc. All cable
entries should be sealed using the correct size cable gl and.
Care must be taken when locating the transmitter to ensure the ambient
temperature remains inside the specified range of (0 t o 70) ºC. The
diagram shows the mechanical layout with a typical application of the
transmitter mounted inside a probe head enclosure.
Mounting Holes: 2 Holes 4.5 mm Diameter, 33 mm Centres
3.2 Electrical
Connections to the transmitter are made to the screw termin als provided
on the top face.
The SEM110 conforms to BS EN 61326 and as such, the radiated
electromagnetic susceptibility is tested to 3 v/m. It is ther efore recommend
that during the installation process, the instrument sh ould be mounted
away from any high powered radio transmitters and awa y from any heavy
switching gear.
To maintain EMC compliance input/sensor wires m ust be less than 3
metres long and output wiring must use screened t wisted pair cable with
the screen earthed at one end only.
All three input wires must have the same core diameter to maintain equal
lead resistance in each wire. T/C sensors must be ung rounded.
The transmitter is protected against reverse connectio n by means of a
series diode, therefore incorrect connection of the ou tput wires will result in
near zero current flow in the loop. Incorrect connection or failure of the
sensor wires will result in the transmitter saturating, T/C versions go
upscale, whilst resistance sensor inputs go either upscal e or downscale
dependant upon which wire breaks. The most comm on failure would be a
total sensor burnout, in which case the
transmitter will go upscale.
3.3 connections
Pt 100, 3 Wire
Only TC with Isolated Junction
Type D, Differential Temperature
Type W, Slide wire
Type Z, Variable Resistor
The diagram shows the method of connection to provid e a (4 to 20) mA
current loop output.
SEM110
TEMPERATURE TRANSMITTER
Designed, manufactured and supported by:
Status Business Park, Gannaway Lane
Tewkesbury Glos. GL20 8FD. UK
Tel: +44 (0)1684 296818 Fax: +44 (0)1684 293746
Email: support@status.co.uk
Every effort has been taken to ensure the accuracy of this specification, however we do
not accept responsibility for damage, injury, loss or expense resulting from errors and
omissions, and we reserve the right of amendment without notice
LOAD
POWER
(24V NOM)
SUPPLY
-
+
Ra-Rb
Rb
Ra
20mA
4mA
3 2.0 1. 8
5 3.0
Z ero
S pa n
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D2133_01_04 CN5082 SEM110 User Guide
The Pt100 sensor shown as an example would no rmally take the form of a
probe assembly with a three wire output. Refer to con nection drawing for
other connection types. The output loop shows a 24 V DC power supply
used to provide loop excitation, the transmitter and a loa d all connected in
series. The load symbol represents other equipment in the loop e.g.
indicators, controllers, loggers etc. Sometimes these instr uments come
with the 24 V supply built in as standard, this simplifi es wiring and reduces
cost. Care must be taken when designing the (4 to 20) m A circuit to
ensure that the total burden of the loop, that is the total vol tage
requirements of all the equipment in the loop added to gether, does not
exceed the power supply voltage. If a number of inst ruments are
connected in the loop, ensure that only one instrument is tied to ground.
Grounding the loop at two points will result in shorting out part of the loop
and therefore any instruments in that part of the loop will not operate.
4.0 Calibration
Calibration is only recommended when the user has acce ss to suitable
equipment, together with a reasonable knowledge of instrumentation
calibration techniques. The following instructions act as a guideline to
calibration.
4.1 A precision cali brator will be required, to simulate the type of
sensor the transmitter is designed for, together with a set of
tables giving the sensor output against process va riable, (e.g.
resistance against temperature for a PT100 sensor). A
precision digital current meter together with a 24 V DC s upply
will also be needed. Read the SEM110 label to est ablish the
transmitter range i.e. the process variable input for 4 mA and
20 mA. The side label also indicates the location of th e span
and zero pots.
4.2 Connect calib rator to input terminals, using the correct
compensation wire for thermocouples inputs and th ree wire
connection for RTD inputs. Connect the output positive t o +24
V, negative to 0 V via current meter. Turn power on.
4.3 Set simulator to 4 mA process variable and adjust ZERO
trimmer for 4.000 mA output. ±0.002mA
4.4 Set simulator to 20 mA process variable and adjust SPAN
trimmer for 20.000 mA output ±0.002 mA.
4.5 Repeat ste ps 4.3 and 4.4 until both points are in calibration.
4.6 Turn power off and remove calibration equipment.
5.0 SEM110X\* VERSIONS - FOR USE IN POTENTIAL LY EXPLOSIVE
ATMOSPHERES
5.1 ATEX Certificate
The SEM110X/* models has been issued with a EC-t ype examination
certificate, confirming compliance with the European AT EX directive
94/9/EC for :-
Intrinsic safety II 1 G EEx ia IIC T5.
The equipment bears the Community Mark and subject to local codes of
practice, may be installed in any of the European Econom ic Area (EEA)
member countries. The SEM110X housing is coloured li ght blue to identify
the equipment as suitable for Hazardous area use. The equipment must
be installed and maintained in accordance with local requirements for
electrical equipment for use in potentially explosiv e atmospheres, eg
EN60079-14 & EN60079-17. This instruction shee t describes installation
which conforms with BS EN60079-14 & BS EN6007 9-17 Electrical
Installation in Hazardous Areas. When designing systems outside the UK,
the local Code of Practice should be consulted.
5.2 Atex marking
Common Information
Manufacturer Status Instruments Ltd
Type Number SEM110X/P
SEM110X/TC
SEM110X/W
CE Marking 0891
Explosive Protection Marking
(Type ia) Intrinsic Safety
II 1 Equipment Group and categor y
G T ype of explosive atmosphere (Gas)
EEx ia IIC T5 Intrinsic safety information
TRL03ATEX21004X Certificate reference
5.3 Special Conditions for Safe Use
As indicated by the Certificate Reference "X" suffix, s pecial conditions
apply for safe use for both intrinsic safety and energ y limitation
applications. They are as follows:-
5.4 Zones, Gas Groups, and T rating.
When connected to a approved system the SE M110X/* may be installed
in:-
Zone 0 explosive gas air mixture continuously present
Zone 1 explosive gas air mixture likely to occur in normal use
Zone 2 explosive gas air mixture not likely to occur and if i t does, it will
only occur for a short time.
Be used in gas groups;-
Group A propane
Group B ethylene
Group C hydrogen
Allowable Temperature classification / ambient temperatu re:-
Intrinsic safety (Type ia)
Class
T5 100°C : Ta = -20°C to +40°C
T4 135°C : Ta = -25°C to +55°C
T3 200°C : Ta = -25°C to +55°C
T2 300°C : Ta = -25°C to +55°C
T1 450°C : Ta = -25°C to +55°C
5.5 Environmental Protection
This equipment must be housed in an enclosure which provides a degree
of protection of at least IP54. The enclosure must be suit able for the
atmosphere and environment in which it is installed (eg If of plastic
material, must be resistant to chemical corrosion, UV light, temperature,
humidity etc.)
5.6 Maintenance
This intrinsically safe equipment contains no user se rviceable, adjustable
or replaceable parts. No attempt should be made to repair a faulty
SEM110X/* transmitter, all units must be returned to t he manufacture for
repair or replacement. Attempt service or replacement of parts may
invalidate the explosive protection features of the eq uipment.
5.7 Connection Diagram
They equipment must be electrically connected as sho wn below:-
SEM110X\* Working Parameters
Ui 28 V
I i 93.3 mA
Pi 0.653 W
Ci 0 nF
Li 0 uH
-
SE M11 0XCA LIBR AT OR
DC
+ -
+
24 V
A
SENSOR
SEM110X
3 1
4
5
2
BARRIER
Maximum
output
Vo 30V
Io 100mA
Po 750mW
DC
SUPPLY
+
-
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