WIKA DA10 - Manual (Page 3)

INSTRUCTION MANUAL
NI-209E
Rev. 4 12/02
Fig. 2 - Electrical connections and adjustment screws
One contact instruments Two contact instruments Microswitch electrical circuit:
State of the contacts at
atmospheric pressure
1 - Microswitch set point calibration screw
3 - Terminal block
4 - Electrical connection identification
plate 1 – Microswitch 2 set point calibration screw
2 – Microswitch 1 set point calibration screw
3 – Terminal block
4 – Electrical connection identification plate Designation of the contacts:
C - common
NA - Normally open
NC - Normally closed
5. SET POINT CALIBRATION
In order to proceed with the calibration and the
periodical functional verification of the instrument a
suitable calibration circuit (fig. 5) and an adequate
pressure source is required.
5.1 PRELIMINARY OPERATIONS
Weatherproof pressure switches (Series DW) (Fig.
3)
Remove the blocking device fixed to the side of the
instrument case and the adjustment screw access plate.
Remove the cover be rotating it anticlockwise.
Fig. 3 -
Weatherproof pressure switch cover blocking device
and plumbing
a) Plumbing wire
b) Plumbing
c) Blocking nut
c) Blocking bracket
e) Adjustment screw access
plate
Explosionproof pressure switches (Series DA) (Fig.
4)
CAUTION: do not open the cover of explosionproof
pressure switches (Series DA) when energized, in
explosive atmospheres.
Loosen the locking headless screw situated on the
cover using a 1,5 hexagonal key then unscrew the
cover. Remove the internal blocking device inserted on
the closure plugs and slide out the plugs.
Fig. 4 -
Explosionproof pressure switch cover blocking device
5.2 CALIBRATION CIRCUIT AND OPERATIONS
Prepare the control circuit as indicated in Fig.5.
The warning lamps should be connected to contact 1 or
2 in the NO or NC position according to the required
contact action.
Connection of C and NO terminals
•••• If the circuit is open at the working pressure, the switch
closes the circuit as the pressure increases when the
desired value is reached.
• If the circuit is closed at the working pressure, the
switch opens the circuit as the pressure decreases
when the desired value is reached.
Connection of C and NC terminals
• If the circuit is closed at the working pressure, the
switch opens the circuit as the pressure increases
when the desired value is reached.
• If the circuit is open at the working pressure, the switch
closes the circuit as the pressure decreases when the
desired value is reached.