NI-491E
INSTRUCTION MANUAL
Rev. 5 11/02
COMPACT TEMP. SWITCHES SERIES TCS & TCA
Stem type B Stem type C, Q, R
Y = 125 mm Stem type C: K = 2m ; Y max.=350mm
WEIGHT 1kg dimensions in mm WEIGHT 1kg dimensioni in mm
NOTE: dimensions and weights are not binding unless released on certified drawings.
CAUTION
• Before installing, using or carrying out maintenance on the instrument it is necessary to read and understand the indications given
in the attached Instruction Manual.
• The instrument must only be installed and maintained by qualified personnel.
• INSTALLATION IS TO BE CARRIED OUT ONLY AFTER CHECKING THAT INSTRUMENT CHARACTERISTICS ARE
CONSISTENT WITH PROCESS AND PLANT REQUIREMENTS.
• The functional features of the instrument and its degree of protection are shown on the identification plate fixed to the case.
CONTENTS:
1 - GENERAL NOTES
2 - OPERATING PRINCIPLE
3 - IDENTIFICATION PLATE AND MARKINGS
4 - SET POINT REGULATION
5 - SET POINT CALIBRATION
6 - INSTRUMENT PLUMBING
7 - MOUNTING AND CONNECTIONS
8 - PUTTING INTO OPERATION
9 - FUNCTIONAL VERIFICATION
10 - TROUBLESHOOTING
11 - STOPPING AND DISMOUNTING
12 - DEMOLITION
13 - INSTALLATION REMARKS
SAFETY INSTRUCTIONS FOR USE IN HAZARDOUS ATMOSPHERES.
RECOMMENDATIONS FOR PRESSURE SWITCH SAFE USE.
Stem type Q: K = 4m ; Y max.=900mm
RELATED DOCUMENT
To authentified document with certificate
Stem type R:
K = 10m ; Y max.=1800mm
N° CESI 02 ATEX 118
All data, statements and recommendations supplied with this manual are based on information believed by us to be reliable. As the
conditions of effective use are beyond our control, our products are sold under the condition that the user himself evaluates such
conditions before following our recommendations for the purpose or use foreseen by him.
The present document is the property of ETTORE CELLA SPA and may not be reproduced in any form, nor used for any purpose
other than that for which it is supplied.
INSTRUCTION MANUAL
1 - GENERAL NOTES
1.1 FOREWORD
The wrong choice of a series or a model, as well as the incorrect
installation, lead to malfunction and reduce instrument life. Failure
to abide by the indications given in this manual can cause damage to the instrument, the environment and persons.
1.2 ALLOWED OVERRANGE
Temperatures exceeding the working range can be occasionally
tolerated provided they remain within the limits stated in the instrument features (trial temperature). Continuous temperatures
exceeding the working range can be applied to the instrument,
provided they are clearly stated in the instrument features. The
current and voltage values stated in the technical specifications
and ratings must not be exceeded. Transitory overranges can
have a destructive effect on the switch.
1.3 TEMPERATURE
Due to the temperature of both the environment and the process
fluid, the temperature of the instrument could exceed the allowed
limits (normally from -20° to +70°C). Therefore in case it does,
suitable measures (protection against heat radiation, heated
lockers), aimed at limiting the value, must be taken.
2 - OPERATING PRINCIPLE
The operating principle is based on a pressure measuring element, connected via a capillary tube to a temperature-responding
bulb. This system is partially filled with a volatile liquid, the residual free volume being filled by its saturated vapour. In this system
a pressure is generated which is a non-linear function of bulb
temperature; this pressure acts on a stainless steel diaphragm
which applies a force to a stiff disc; this force is directly proportional to the temperature value to which the bulb is submitted and
is contrasted by an helicoidal spring charged by a suitable bush.
When the force balance point is exceeded, the stiff disc shifts
and, by means of a rigid rod, activates one or two simultaneous
release electric microswitches. The microswitches are of the
rapid release type with automatic rearm. When the temperature
moves away from the set values, returning towards the normal
values, the switch is rearmed.
3 - IDENTIFICATION PLATE AND MARKINGS
The instrument is fitted with a metal plate bearing all its functional
characteristics and – in case of explosionproof execution (Series
TCA) – also the markings prescribed by standard CEI EN 50014.
Fig. 1 shows the plate mounted on explosionproof instruments.
Fig. 1 - Explosionproof instruments plate
NI-491E
Rev. 5 11/02
on the ratings as these are temporary and will be modified with
the definitive values. Prior to installation the instrument must be
calibrated and the definitive calibration values written on the
adhesive rating plate using a suitable indelible ink pen.
If the instrument has been ordered with a specific calibration, it
is a good rule to check the calibration values marked on the
relevant adhesive label, prior to installation.
The position of the adjustment bush is given in figure 2
Fig. 2 - Electrical connections and regulating screws (one
contact/two contacts instruments)
1) External earth screw
2) Hole for test plug
3) Adjustment rod for set point calibration
4) Adjustment bush access plate
5) Adjustment bush
6) Screws for fixing the adjustment bush access plate
7) Internal earth screws
8) Terminal block for the second microswitch
9) Terminal block for the first microswitch
10) Pre-insulated test prod thimbles
11) Ventilation path
Microswitch electrical circuit: State of the contacts at a temperature of 0°C
1 CE marking and identification number of the notified body
responsible for production surveillance.
2 Apparatus classification according to ATEX 949 CE directive.
3 Type of protection and ambient temperature limits of opera-
tion.
4 Notified body that issued the type certificate and number of
said certificate.
4 - SET POINT REGULATION
The charge of the helicoidal spring can be regulated by means of
the bush (for adjustment) in such a way that the switch is released
when the temperature reaches (increasing or decreasing) the
desired value (set point). The instrument is usually supplied with
the switches set at 0°C or at the lowest setting range value if this
is higher than 0°C (factory calibration). The instrument is supplied with an adhesive rating plate showing the set point calibration value. With factory calibration the values are not indicated
Designation of the contacts:
C - common
NA - Normally open
NC - Normally closed
The effect that the direction of rotation of the adjustment bush has
is described on the ratings.
The bush must be turned by means of the appropriate adjustment
rod which comes with the instrument (fig.2).
5 - SET POINT CALIBRATION
In order to proceed with the calibration and the periodical functional verification of the instrument a suitable calibration circuit
(fig. 3) and an adequate heat source is required.
INSTRUCTION MANUAL
5.1 PRELIMINARY OPERATIONS
CAUTION: do not open the cover of explosionproof temperature
switches (Series TCA) when energized, in explosive atmospheres.
With reference to Fig. 3 unscrew the screw (b) until the blocking
device (a) can be turned 180°; then unscrew the cover.
Fig. 3 - Weatherproof temperature switch blocking device
a. Cover blocking
device
b. Blocking screw
c. Screw blocking the
adjustment bush ac-
cess plate
d. Flexible steel wire
e. Plumbing
f. Adjustment bush
access plate
5.2 CALIBRATION CIRCUIT AND OPERATIONS
Prepare the control circuit as indicated in Fig. 4.
The warning lamps should be connected to the contact in the NO
or NC position according to the required contact action.
If the instrument is equipped with two microswitches, take into
account that they actuate simultaneously within rated tolerances.
The warning lamps can either be connected by means of a test
prod thimble with a maximum diameter of 2.5 mm or by means of
a test plug with a diameter of 2 mm to be inserted in the appropriate holes situated frontally beside the terminal screws (see fig. 2).
Fig. 4 - Calibration circuit
TS - Temperature switch
TT - Test thermometer
TB - Thermostatic bath
Connection of C and NO terminals
• If the circuit is open at the working temperature, the switch
closes the circuit as the temperature increases when the desired
value is reached (MAX. closing).
• If the circuit is closed at the working temperature, the switch
opens the circuit as the temperature decreases when the desired
value is reached (MIN. opening).
Connection of C and NC terminals
• If the circuit is closed at the working temperature, the switch
opens the circuit as the temperature increases when the desired
value is reached (MAX. opening).
• If the circuit is open at the working temperature, the switch
closes the circuit as the temperature decreases when the de-
sired value is reached (MIN. closing).
NI-491E
Rev. 5 11/02
The test instrument should have a measurement range approximately equal to or slightly wider than the temperature switch
range and should have an accuracy consistent with the precision
required to calibrate the set point.
The temperature switch must be mounted in the normal installation position, i.e. with the stem or capillary outlet downwards.
Avoid forcing the microswitch by hand or with tools. This could
affect the instrument functioning.
With reference to figure 3, free the access to the adjustment bush
by loosening the screw (c) which holds the closure plate (f).
Increase the circuit temperature up to the desired microswitch set
point value.
Turn the adjustment bush using the adjustment rod with which the
instrument is equipped (fig.2) until the relative lamp turns on (or
turns off); then turn it in the opposite direction until the lamp turns
off (or on). Slowly turn the bush again until the lamp turns on (or
off).
Check the calibration value (varying the temperature in the circuit
accordingly) and register it, using a pen with indelible ink, on the
ratings.
5.3 FINAL OPERATIONS
Disconnect the instrument from the control circuit.
5.3.1
With reference to figure 2, insert the adjustment rod into the
appropriate seat; close the access to the adjustment bush by
rotating the closure plate (4) and tighten the relative screw (6).
Take the cover, ensure that the sealing gasket is correctly fitted
into its seat, insert the cover onto the case and turn it clockwise
until the cover is closed.
With reference to figure 3 turn the blocking device (a) 180° sliding
the tongue into the appropriate seat in the cover; tighten the
blocking screws (b).
Replace the supplied protection cap on the cable conduit.
CAUTION: the protection cap should only be definitively removed
during the connection steps (see § 7).
6 - INSTRUMENT PLUMBING
The plumbing, aimed as a guarantee against possible tampering
of the calibration, can be carried out using a flexible steel wire (d)
inserted into the holes in the screw (c) and the adjustment bush
closure plate provided for this purpose (see Fig. 3).
7 - MOUNTING AND CONNECTIONS
7.1 MOUNTING
Surface mount the instrument by means of the holes provided, or
pipe mount using the appropriate bracket (see figures 6 and 7) in
a vertical position (with the stem or capillary outlet pointing downwards). The chosen position must be such that vibrations, accidental shocks or temperature changes are within tolerable limits.
The above also applies to direct mounting. For the instruments
equipped with capillary the difference between the bulb and the
case must not exceed two metres.
CAUTION: positions other than vertical are allowed provided
environmental conditions do not cause condensation to form or
water to enter the instrument through the ventilation path.
7.2 BULB AND CAPILLARY
With reference to figure 5 svitare il raccordo (3) dal premiguarnizione (2) e sfilarlo dal bulbo (5).
unscrew the fitting (3) from the seal press (2) and slide it off from
the bulb (5).
Mount the fitting (3) on the thermowell (4) and tighten it using the
appropriate key.
Insert the bulb (5) into the thermowell (4) after covering it with the
paste to improve the transmission of heat.
Verify that the bulb touches the bottom.
Insert the PTFE seal with the relative stainless steel washers into
the fitting (3).
Screw the seal press (2) onto the fitting (3) taking care not to
bend the capillary and relative sheath and tighten until the PTFE
seal is tight on the capillary tube.
INSTRUCTION MANUAL
Fig. 5 - Mounting the bulb
1) Armored capillary
2) Stuffing nut (SW 12)
3) Rotating fitting (SW 22)
4) Thermowell
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 according to the applicable standards. In case of explosionproof instruments (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.
5) Bulb
6) Stainless steel washer
7) PTFE washer
NI-491E
Rev. 5 11/02
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
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 without 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 atmospheres.
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.
2
(16AWG) are
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
Slow response
No actuation
Undue actuation
Deposits on thermowell or bulb.
Filling fluid leakage.
Deposits on thermowell or bulb. Check and clean surfaces.
Loosened electrical joints.
Interrupted or short-circuited electrical line.
Microswitch contacts damaged.
Filling fluid leakage.
Accidental shocks.
Interrupted or short-circuited electrical line.
Check and clean surfaces.
Replace the instrument.
Check all electrical joints.
Check the conditions of the electrical line.
Replace the instrument.
Replace the instrument.
Modify the mounting.
Check the conditions of the electrical line.
INSTRUCTION MANUAL
11 - STOPPING AND DISMOUNTING
Before proceeding with these operations ensure that the plant or
machines have been put into the conditions foreseen to allow
these operations.
With reference to figures 6 and 7
Remove the power supply (signal) from the electrical line.
Loosen and remove the seal press being careful not to bend the
capillary and protective sheath (Fig. 5).
Loosen and remove the fitting then extract the bulb from the
thermowell holding it by the capillary tube, without bending it.
Unscrew the three piece joint (8).
CAUTION: do not open the cover of explosionproof temperature
switches (Series TCA) when energized, in explosive atmospheres.
Unscrew the three piece joint (10) (electrical cable tubing).
Remove the instrument cover and disconnect the electrical cables from the terminal block and earth screws.
Remove the screws fixing the case to the panel (or pipe) and
remove the instrument, taking care to slide the electrical conductors out from the case.
Mount instrument cover. Insulate and protect cables around, if
any. Temporarily plug the thermowell. In case of explosionproof
instruments (Series TCA) it is recommended to follow - at least –
the standard EN-60079-17 for the withdrawal from service of
electrical apparatus.
NI-491E
Rev. 5 11/02
12 - DEMOLITION
The instruments are mainly made of stainless steel and aluminium and therefore, once the electrical parts have been dismounted and the parts coming into contact with fluids which could
be harmful to people or the environment have been properly dealt
with, they can be scrapped.
13 - INSTALLATION NOTE
13.1 TEMPERATURE SWITCHES CLASS SAMA II A
Difference in height of more than two meters between bulb and
instrument enclosure causes a systematic error of set point calibrated value (“bulb elevation error”).
This error can be corrected during calibration by either increasing
or decreasing the set point value by a constant depending on the
difference in height foreseen for the installation. The “bulb elevation error” can be corrected using the table attached to our technical instruction IS-TC.401E, available on request.
13.2 TEMPERATURE SWITCHES CLASS SAMA II C
Difference in height between bulb and instrument enclosure when
installed must not exceed two meters.
With a difference of approximately two meters the set point value
fixed during calibration may be affected by an error depending on
the normal reference temperature, the working temperature and
the set point temperature. In the worst operating conditions the
set point temperature value fixed during calibration may be affected by a maximum error of 1.5°C. For further clarification
request IS-TC.401E.
INSTRUCTION MANUAL
WEATHERPROOF EXPLOSIONPROOF
Fig. 6 - Example of connections - Fig. 7 - Example of connections -
NI-491E
Rev. 5 11/02
1) Weatherproof temperature
switch series TCS
2) Capillary
3) Thermowell
4) Bulb
5) Derivation
Fig. 8 - Thermometric wells: example of installation
Minimum dimension 3”: for lesser dimensions provide for an
Dimensione minima 3"; per dimensioni minori provvedere ad
Minimum dimension 6”: for lesser dimensions provide for an
Dimensione minima 6"; per dimensioni minori provvedere ad
increase in diameter up to 3”
un incremento del diametro fino a 3".
increase in diameter up to 6”
un incremento del diametro fino a 6".
6) Process piping
7) 2” pipe
8) Bracket for 2” pipe
9) 3 piece joint
1) EEx-d temperature switch
series TCA
2) Capillary
3) Thermowell
4) Bulb
5) Derivation
6) Process piping
7) 2” pipe
8) Bracket for 2” pipe
9) 3 piece joint
10) Blocking joint
ETTORE CELLA SPA Viale de Gasperi, 48 - Casella Postale (P.O. Box) 96 - I 20010 Bareggio (MILANO) ITALY
Telefoni +39 029036.1146/1237/1241 - FAX +39 029036.1331 E-MAIL: CELLA@ECELLASPA.COM
Loading...