WIKA TXA - Manual (Page 4)

INSTRUCTION MANUAL
NI-492E
Rev. 0 01/05
Fig. 6 - Mounting of ground device
DO NOT TURN
8.3.2 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. 6).
The external ground screw is obligatory for explosionproof
constructions.
If the flexible tubing is fitted with a male thread, apply a sleeve to
the electrical connection.
CAUTION: the sleeve is to be threaded on while holding the
electrical connection steady with a 27 mm wrench on hex
(Fig.7)
.
Fig. 7 - Mounting of adaptors
DO NOT TURN
8.3.3 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 (Fig. 7).
In order to make the instrument removal easier for check and
calibration it is advisable to apply the instrument a junction box
provided with terminals.
CAUTION: accessories used for installation have to be certified
according to standards EN 50014, 50018, EN 50281-1-1 and
guarantee the degree of protection of the instrument (IP65).
8.3.4 MOUNTING WITH INSTRUMENT FITTED WITH
JUNCTION BOX
Models fitted with junction box feature three cable entries, three-
or six-terminals block with terminals identification plate, internal
and external grounding connections.
Terminals are identified as follows:
Identification No.
Function Micro No.
1 Common
2 Normally
Open
3 Normally Closed
1
4 Common
5 Normally
Open
6 Normally Closed
2
Mounting with cable protected is to be carried out so as to
prevent possibile condensate from entering the junction box
The junction box is to be surface mounted using the bracket
suppiled with it.
CAUTION: accessories used for installation have to be certified
according to standards EN 50014, 50018, EN 50281-1-1 and
guarantee the degree of protection of the instrument (IP65).
CAUTION: cable entries not used must be plugged and sealed
with the plugs provided so as to prevent raining water or other
from entering the junction box. In case of explosionproof
instruments these plugs, if not correctly mounted and
blocked to prevent their removal, do NOT guarantee the
mode of protection EEx-d. Furthermore, in order to guarantee
the degree of protection IP65 and the non-loosening of blocking
joint or packing gland, it is prescribed to seal the threads of
connection with the same anaerobic sealant used for the plugs.
For instance, a sealant like Loctite ® 648 can be applied on the
thread of plugs, blocking joint or packing gland before screwing
them on the box.
8.4 WIRING
The cable used for electric wirIng has a 7 mm OD silicone sheat
for one contact models, 8 mm OD for two contact models. Each
wire has a section of 0,5 mm
2 (20 AWG) and is silicone insulated.
Wires ends are factory tinned. The colour of insulator defines the
contact function (see Fig. 3 and stampings on slot cover).
Before starting wiring, check that electric lines are not
powered.
The instrument is to be grounded according to applicable
electrical codes. Make use of the internal yellow-green wire and,
if the cable is not protected by metal tubing, connect the external
screw of the groundig device supplied with the instrument.
Should the instrument be fitted with junction box, make sure that
no deposits or wire ends remain inside the box. The wiring
completed, put the cover on and tighten it.
8.5 SPECIAL NOTE FOR THE INSTALLATION OF
TEMPERATURE SWITCHES CATEGORY 3GD, MODE OF
PROTECTION EEx - nC
Explosionproof instruments Series TXN are to be installed using
electric accessories prescribed for this execution. For instance,
junction boxes are to be suitable for mode of protection n. Apply
to standards EN-50021 for any construction detail and to EN-
60079-14, EN-50281-1-2 for installation.