INSTRUCTION MANUAL
NI-492WE
Rev.4 05/18
4 of 7
9.2.2 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 two meters the set point value fixed during
the calibration may be affected by a maximum error of 1.5°C.
This error depending on the normal reference temperature, the
working temperature and the set point. For further clarification
request
IS-TC.401E
.
9.3
BULB AND CAPILLARY
With reference to figure 5 unscrew the fitting (3) from the seal
press (2) and slide it off from the bulb (5).
Fig. 5 – Mounting of 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
Mount the fitting (3) on the thermowell (4) and tighten it using the
appropriate key. Rid the capillary from the armored by pulling the
bulb (5) with one hand while holding the stuffing nut with the other
(2).
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.
Run
the capillary protected by the armor 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.
9.4 TEMPERATURE SWITCHES WITH HELICAL
BULB
The temperature switch has to be installed protecting the sensing
element (bulb) against heat radiation and accidental bumps .
Fig. 6 -
Temperature switch for ambient temperature measurement
9.5 ELECTRICAL CONNECTIONS
It is recommended to carry out the electrical connections
according to the applicable standards. In case of flameproof or
intrinsic safety instruments see also the standards IEC/EN-
60079-14. The following mounting arrangements are possible.
9.5.1 MOUNTING WITH CORD CABLE
Run the cable so that it cannot be easily damaged (e.g. due to
too narrow bends, heat sources) and strain it.
Mount, if provided, the external ground device on the electrical
connection of the instrument.
The external ground screw is obligatory for flameproof
constructions.
This device is to be threaded on while holding the electrical
connection steady with a 27 mm wrench on hex, until it reaches
the bottom of the thread (Fig. 7).
Fig. 7 - Mounting of ground device
DO NOT TURN
9.5.2 MOUNTING WITH CABLE PROTECTED BY
FLEXIBLE TUBING
Mount, if provided, the external ground device on the electrical
connection of the instrument. This device is to be threaded on,
while holding the electrical connection steady with a 27 mm
wrench on hex, until it reaches the bottom of the thread (fig. 8).
The external ground screw is obligatory for flameproof
constructions.
If the flexible tubing is fitted with a male thread, apply a nipple to
the electrical connection.
CAUTION:
the adaptor is to be threaded on while holding the
electrical connection steady with a 27 mm wrench on hex (fig.8)
Fig. 8 - Mounting of adaptors
DO NOT TURN
9.5.3 MOUNTING WITH CABLE PROTECTED BY
METAL TUBING
CAUTION:
mounting with cable protected by metal tubing is to
be carried out avoiding any torque on the electrical connection
while assembling the various fittings.
In order to make easier the instrument removal for check and
calibration it is advisable to apply on the instrument a junction
box provided with terminals.
CAUTION:
accessories used for installation have to be certified
according to standards EN or IEC
