WIKA SC Series User manual

Operating Instructions
Betriebsanleitung
GB
D
Combistat, mechanical Temperature Regulator
Model SC
Combistat, anzeigender Temperaturregler
Typ SC
Combistat, Mechanical Temperature Regulator SC15

GB
D
Operating Instructions Combistat,
mechanical Temperature Regulator Model SC Page 3 - 10
Betriebsanleitung Combistat,
anzeigender Temperaturregler Typ SC Seite 11 - 18
2
11482690 09/2009 GB/D
WIKA Operating Instructions Combistat Model SC

GB
Contents
1. Safety instructions 4
2. Application 4
3. Design and operating principle 4
4. Technical data 5
5. Installation, commissioning and operation 6
6. Troubleshooting 8
7. Indicator check 8
8. Indicator correction 9
9. Maintenance and servicing / Cleaning 10
10. Repairs 10
11. Disposal 10
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WIKA Operating Instructions Combistat Model SC 3
Contents
Information
This symbol provides you with information, notes and tips.
Warning!
This Symbol warns you against actions that can cause injury to
people or damage to the instrument.

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1. Safety instructions / ... / 3. Design, operating principle
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WIKA Operating Instructions Combistat Model SC4
1. Safety instructions
The appropriate national safety regulations (e.g. VDE 0100)
must be observed when installing, commissioning and
operating these devices.
Serious injuries and/or damage can occur should the appropriate
regulations not be observed.
Only appropriately qualified personnel should carry out the connection
work.
Any connection work may only be carried out once the equipment has
been isolated.
2. Application
Universally applicable safety temperature regulator for gaseous, liquid and
highly-viscous process media.
3. Design and operating principle
The fluid-filled, closed measuring system consists of a temperature sensor, a
measuring capillary and a bourdon tube. Heating the temperature sensor leads
to a volume change in the closed system and thus a change in the pressure.
This is transferred through a measuring capillary to the bourdon tube and,
through the angular motion of the pointer shaft, to the dial on the display.
When the switch point is passed, the switch disc (cam disc), fitted to the
pointer shaft, triggers the micro switch.
Apart from the standard version with 1 or 2 adjustable micro switches there are
further combinations such as:
1 or 2 non-adjustable micro switches
1 non-adjustable and 1 variable adjustable micro switch
Case steel with 3 or 4 fixed switches
The switch points of the non-adjustable micro switches are printed on the
product label.
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4. Technical Data
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WIKA Operating Instructions Combistat Model SC 5
4. Technical Data
Ingress protection
Case IP 53, terminals IP 00 (EN 60 529 / IEC 529)
Scale range
100 °C ... 400 °C
Permissible temperatures
Case: +60 °C
Capillary:
plastic sheathed -40 °C ... +100 °C
copper braided -40 °C ... +350 °C
Scale limits
Max. 270 °p
Measuring principle
Bourdon tube system
System filling
Xylol, silicon oil, syltherm or nitrogen
Capillary
Plastic sheathed or copper braided,
capillary of copper or stainless steel 1.4571 depending on scale range
Capillary length
Max. 10 m
Capillary outlet
Lower back
Contact
Micro switches (fixed or adjustable)
Load data
5 A, 250 V AC
There is no overcurrent protection fitted to these instruments. In order to
prevent the switches being welded through overload, a suitable protection
device should be fitted by the user.

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4. Technical data / 5. Installation, commissioning, operation
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WIKA Operating Instructions Combistat Model SC6
Standard switch differential
< 2 % of the measuring range at the reference temperature of 23 °C at the case
and capillary
Electrical connection
0.8 x 0.63 mm terminal block or AMP plug connection
Case
Plastic (ABS), black or steel
Type of mounting
Panel mounting with clamp
(NS 100: steel case with panel mounting flange)
Options
Panel mounting flange
Protection cap IP 51 or IP 54
Case steel with 3 or 4 fixed micro switches
5. Installation, commissioning and operation
When fitting and using the instruments, the following
fundamental requirements must be followed:
The display range of the safety temperature regulator should be chosen
so that the maximum temperature at the sensor does not exceed the
display range. Also, after the switchpoint has been exceeded, a
resultant reheating process has to be taken into account.
In operation the equipment should not be subjected to strong vibration
or impact loads.
Contamination and high ambient temperature fluctuations should be
avoided.
Any break in the capillary will destroy the instrument and result in it
switching off.
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5. Installation, commissioning and operation
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WIKA Operating Instructions Combistat Model SC 7
Electrical connection
The connection diagram is shown on the instrument label on the
outer rim of the case.
5.1 Installation condition
Before installing the probe, check whether the probe material used (specified
in the delivery note) is chemically resistant/neutral to the medium being
measured. This also applies to thermowells.
Ensure that all the necessary accessories for the mounting method ordered
have been supplied e.g. instrument mounting brackets, clamp straps for panel
mounting, contact adjustment buttons, etc..
The accessories will be either on the instrument or supplied in a separate bag,
which in most cases will be attached to the thermometer.
If possible, the entire length of the stem should be exposed to the tempera-
ture to be measured, but, if not, it should at least be the length of the active
part (active length), which corresponds to the length of the expansion vessel.
In pipelines or other measuring points the temperature probe should be
directed as far towards the flow as possible.
If a thermowell is used, the stem must not be allowed to touch the bottom of
the thermowell.
Capillaries must be kink protected. The minimum bending radius for
capillaries should not be less than 6 mm. Any kinks or discontinuities in the
capillary may result in the failure of the instrument.
If the probe is installed in a location which is exposed to shock and vibration,
it is essential that the capillary is coiled in several loops, and free of tension
between the last attachment point and the probe. Any excess length should
also be coiled into loops, as cutting the cable would make the instrument
unserviceable.
Any welding or soldering of the capillary, as well as any permanent fastening
of the capillary, must be avoided, as this can severely damage the capillary,
and impair the operation of the instrument.
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5. Installation, commissioning, operation ... 7. Indicator check
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WIKA Operating Instructions Combistat Model SC8
5.2 Ambient conditions
Unless the ingress protection of the thermometer's case is specifically identified
in the order confirmation, the instrument must be protected from humid air and
other aggressive atmospheres.
The ambient temperature at the indicator case should be between 0 °C ... + 40 °C
in order to ensure the best possible measuring accuracy. Higher or lower ambient
temperatures can lead to indication errors .
6. Troubleshooting
Expansion thermometers with micro switch sare maintenance-free instruments
according to their basic design. As measuring instruments, their measuring
accuracy should be checked at application-specific intervals.
The wear condition of probes exposed to a permanent thermal stress (even
if this stress is very low), of electro-mechanical contacts and of capillaries
exposed to vibratory stress must be checked from time to time.
If any visible damage is found, the instrument must be replaced.
7. Indicator check
Indicator checks should only be carried out in comparison with a more accurate
instrument or, if possible, with a calibrated instrument. The temperature during
the check must remain constant. Fluctuating temperatures can lead to reading
errors caused by the different response times of the probes.
Before checking the indicators of thermometers without thermowells, a waiting
time of at least 5 minutes with the stem‘s full length properly inserted is
required to allow temperature equalisation.
Temperature checks using thermometers with probes assembled with thermo-
wells can, in many cases, only result in a reference temperature at the
instrument under test, due to permanent heat dissipation caused by the
thermowell. In temperature applications fitted with static checking thermo-
meters (e.g. pipeline systems), permanent offsets in reference temperatures can
also be caused by the heat transfer path.
Ambient temperatures around the indicator housing which differ substantially
from room temperature can lead to steady indication errors with constant
ambient temperatures and to varying indication errors with fluctuating ambient
temperatures.
Permanent indication errors caused by the ageing of the measuring system can
be ignored, as they only account for a fraction of the indication accuracy.

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8. Indicator correction
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WIKA Operating Instructions Combistat Model SC 9
8. Indicator correction
Any interference with or modification to the instrument will
invalidate the warranty!
Indicator corrections may only be carried out by the manufacturer or in
adequately equipped workshops by qualified persons.
Electrical connection should only be carried out by qualified electricians
The switches are terminated on screw terminals or spade plug
Conductor cross-section max. 1.5 mm2
The terminal assignment is stated on the connection plate of the thermometer
To adjust red set pointers
The red set pointers are adjustable via the adjustment lock on the window.
The red set pointers for the micro switches are adjustable over the full range
of the instrument. Switching points should be set in the range between 10 %
und 90 % of the full scale, to ensure switching accuracy and the long life of the
measuring mechanism.
The non-adjustable switching points to customer specifications are not
changeable afterwards.
Surface oxidation at the contact areas may lead to malfunction, which can
result in contact-arcing, particularly in the case of intrinsically safe circuits (low
voltages and currents), and in the case of relatively high contact loads.
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9. Maintenance and servicing, cleaning ... 11. Disposal
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WIKA Operating Instructions Combistat Model SC
10
9. Maintenance and servicing / cleaning
The instruments require no maintenance or servicing.
The indicator and switching function should be checked once or twice every
12 months. For this the instrument must be disconnected from the process and
checked using a temperature calibrator.
The instruments should be cleaned with a damp cloth, moistened with soap
solution. When cleaning the mains power must be disconnected. All parts must
be dry before the power is reconnected.
10. Repairs
Repairs are only to be carried out by the manufacturer or appropriately trained
personnel.
For further details see WIKA data sheet TV 28.02.
11. Disposal
Disposal of instrument components and packaging materials should be in
accordance with the respective waste treatment and disposal regulations of the
region or country to which the instrument is supplied.