WIKA TCA - Manual (Page 4)

INSTRUCTION MANUAL
NI-491E
Rev. 5 11/02
Fig. 5 - Mounting the bulb
1) Armored capillary
2) Stuffing nut (SW 12)
3) Rotating fitting (SW 22)
4) Thermowell
5) Bulb
6) Stainless steel washer
7) PTFE
washer
Extend the capillary protected by the sheath in the established
direction, avoiding tight bends, and block using the stainless steel
bands.
If a large amount of capillary remains this should be rolled up and
fixed tightly. The coil must not have a diameter of less than 200
mm.
7.3 ELECTRICAL CONNECTIONS
It is recommended to carry out the electrical connections accord-
ing to the applicable standards. In case of explosionproof instru-
ments (Series TCA) see also the Standard EN-60079-14. If the
electrical connection is carried out in a protected tube, it shall be
made so that condensate is prevented from entering instrument
enclosure.
The arrangement shown in Fig. 6 or 7 is therefore recommended.
CAUTION: fittings used for the electrical connection of the
pressure switch Series TCA (explosionproof) shall be certified to
Standards EN 50014 and 50018, and shall guarantee instrument
degree of protection (IP65).
Check that there is no power in the lines.
Remove the cover and carry out the cabling and connections to
the terminal block (see Fig. 2).
Flexible cables with a maximum section of 1.2 mm
2 (16AWG) are
recommended using the pre-insulated test prod thimbles with a
maximum diameter of 2.5 mm supplied with the instrument.
When inserting cables into the enclosure pay attention not to
force the microawitch with cable or tools, otherwise instrument
calibration or even its operation could be compromised. The
microswitch has been factory mounted and positioned in order to
obtain the best performances. Any tampering made on site with-
out following instructions authorised by the E. CELLA SPA may
result in instrument malfunction.
Ensure that no deposits or wire ends remain inside the case.
Once the connection operations have been completed, replace
the cover and ensure that it is properly sealed and blocked. See
Fig. 3.
8 - MESSA IN FUNZIONE
As the signal transmitted by the instrument is used in a complex
system, it is necessary that the means of putting it into operation
are established by personnel in charge of the plant
.
The instrument starts working as soon as it is connected to an
electrical line.
In case of explosionproof instruments (Series TCA), initial
inspections are to be carried out according to customer
procedures and at least in accordance with Standard EN-60079-
17.
9 - FUNCTIONAL VERIFICATION
Si effettuerà secondo le modalità previste dal piano di controllo
del Cliente. Series TCS instruments can be verified on the plant if
mounting is done as illustrated in Fig. 6 and 7.
The instruments Series TCA may be checked on site only if
apparatus suitable for explosive atmosphere are used and
provided that the electric line is not energized.
If this is not the case it is necessary to stop operation, dismount
by means of the three piece joints and carry out the verification in
a test room.
CAUTION: do not open the cover of explosionproof temperature
switches (Series TCA) when energized, in explosive atmos-
pheres.
Verification consists in checking the calibration value and
possibly regulatory the adjustment bush (see §5).
In case of explosionproof instruments (Series TCA), inspections
of the electrical installation are to be carried out also according to
customer procedures and at least in accordance with Standard
EN-60079-17.
10 - TROUBLESHOOTING
IMPORTANT NOTE: operations involving replacement of essential components must be carried out at our workshop, especially
for instruments with explosionproof certificate; this is to guarantee the user the total and correct restoration of the product
original characteristics.
MALFUNCTION PROBABLE CAUSE REMEDY
Set point shift
„ Deposits on thermowell or bulb.
„ Filling fluid leakage. „ Check and clean surfaces.
„ Replace the instrument.
Slow response „ Deposits on thermowell or bulb. „ Check and clean surfaces.
No actuation
„ Loosened electrical joints.
„ Interrupted or short-circuited electrical line.
„ Microswitch contacts damaged.
„ Filling fluid leakage. „ Check all electrical joints.
„ Check the conditions of the electrical line.
„ Replace the instrument.
„ Replace the instrument.
Undue actuation
„ Accidental shocks.
„ Interrupted or short-circuited electrical line. „ Modify the mounting.
„ Check the conditions of the electrical line.