Faults - WIKA TS-972 Operating Instructions Manual

5.5 Setting of the switch differential
The handling instructions described here cannot be carried out on instrument versions
with fixed switch differential.
Before setting the switch differential, the handling steps in chapter 5.4 "Switch point
setting" must be carried out.
Remove the deadband
end cap and adjust
deadband spring adjuster
screw with allen key
5. Release/build up the temperature slowly and check the reset point. By rotate range settting
screw anticlock wise to increase the reset point @ desired value on falling temperature.
To increase the dead band by rotate the allen key anti clock wise, switch point alone
increase on rising temperature.
After correcting the switch differential, the switch point must be re-checked.
6. If the switch point and the reset point coincide with the required temperature values,
the switch point and switch differential setting is complete, after setting lock end cap.
7. Close the cover again and fix it with the 4 supplied screws,
8. see chapter 2.1 "Overview".
5.6 Commissioning
Check that the following torques for screw connections are maintained:
■
- Clamping screws and screw for locking plate: Approx. 0.6 Nm
- Case screws: Approx. 1.25 ... 1.5 Nm
The instruments are designed for vertical mounting. The sensing bulb should be fully
■
immersed in the process media.
- The connected electrical load should not exceed declared Voltage & Current rating.
- The process temperature should never exceed the claimed maximum working temperature.
The sensing element will get permanently damaged if temperature exceeds EVEN ONCE.
- Thermowell is a must for non compatible media.
The instrument must not be subjected to any external loading (e.g. use as a climbing
■
aid, support for objects)
Caution:
▶
Do not handle the instrument by it's capillary system.
▶
Do not bend sharp at the bulb or at instrument end
▶
The Instrument should be mounted suitably so as to avoid excessive heat transfer from
the process lines or adjacent plant.
▶
In humid environment where the ambient temperature is sub zero, precautions should
be taken to prevent ice formation within the instruments from the jamming the mecha-
nism.
▶
Avoid temperature shocks
For pressurized application, where line pressure is more than 1 bar, or, when temperature
is higher than boiling point, thermowell is recommended to be used.
WIKA operating instructions, temperature switch with adjustability of switch differential, model TS-972

6. Faults

CAUTION!
Physical injuries and damage to property and the environment
If faults cannot be eliminated by means of the listed measures, the instrument
must be taken out of operation immediately.
Ensure that there is no temperature in the instrument and that the load circuit is
switched off. Protect against being put into operation accidentally.
Contact the manufacturer.
If a return is needed, please follow the instructions given in chapter 8.2 "Return".
WARNING!
Physical injuries and damage to property and the environment caused by
media
Upon contact with hazardous media, harmful media (e.g. corrosive, toxic,
carcinogenic), and also with refrigeration plants and compressors, there is a
danger of physical injuries and damage to property and the environment.
Should a failure occur, aggressive media with extremely high temperature
For these media, in addition to all standard regulations, the appropriate existing
codes or regulations must also be followed.
For contact details see chapter 1 "General information".
Faults Causes
Contact is not Electrical connection is
switching in interrupted.
accordance with the
Wiring error, e.g. short
specification at the
circuit.
set switch point/reset
Electrical load
point
unsuitable for the
switch contact model.
Contact contaminated. Replace instrument
Switch differential
greater than the switch
point.
Vibrations
Short circuit Moisture in the
instrument.
Measures
Carry out a continuity test on the
electrical connection lines.
Check the pin assignment and
correct it if necessary.
Maintain the permissible electrical
loads for the switch contact model.
Carry out switch point setting
with matching test assembly,
see chapter 5.4.
Decouple the instrument
mechanically.
Only use in ambient conditions
for which the ingress protection is
suitable.
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