Electrical Connections - Sit 837 TANDEM Manual Del Usuario

MECHANICAL CONNECTIONS (fig. 1)
General recommendations
Do not tamper with sealed parts. Do not slacken assembly screws. Do not remove labels. Avoid blows (knocks, falls
etc.). Only remove inlet and outlet dust caps immediately prior to installation. Do not exceed recommended torques.
Ensure that the gas flows in the direction shown by the arrow on the valve body. Prevent foreign matter from getting
into the valve during installation. In particular, check the cleanliness of the inlet and outlet pipes. Do not immerse
in water or subject the valve to temperatures exeeding 80°c.
Do not subject the valve to bending in excess of 35 Nm and to torque in excess of 25 Nm.
Use only the specified spanner grips when making the connections.
Main gas connection
The connection must be made using gas pipes with Rp 1/2 ISO 7 thread. Torque: 25 Nm.
If, alternatively, flanges (available on request) are used, first screw the pipes onto the flanges and then the flanges
to the valve.
Recommended torque for flange retaining screws: 3 Nm.
Connection to the pilot burner (versions with pilot burner outlet):
Ø4 mm, Ø 6 mm or Ø 1/4" pipes can be used. Use appropriately sized nut and olive. Tighten to 7 Nm torque.
WARNING: if the pilot outlet is not used it must be sealed using optional plug code no. 0.972.041. Torque: 7 Nm.
Connection to the combustion chamber (fig. 2)
Connecting the pressure regulator to the combustion chamber is recommended when this is pressurized.
Use the special hose nipple (dia. 6 mm).

ELECTRICAL CONNECTIONS

General precautions
All electrical connections must be made in accordance with current electrical standards. Check that the voltage
and frequency of the coils, given on the valve, are correct. Check that all connections, in particular the earth, are made
properly.
To ensure that valves powered at mains voltage are always connected to the earth circuit of the appliance, it is
necessary for the power connector of the safety solenoid valves, including the earth terminal, to be used at all times
while ensuring that the fastening screws are never slack.
The 24 VAC versions must be powered by means of an insulating transformer (with very low safety voltage in
accordance with EN 60742). To connect, use AMP 6.3 x 0.8 mm terminals.
Make the connections as specified in the technical instructions for the flame failure device used and/or in the specific
standards for the appliance. The electrical safety cut-off devices (for example, the flame failure device, thermostat etc.)
must cut off the power supply to both solenoid valves simultaneously.
Wiring diagrams
Shut-off automatic valves
EV 1 EV 2 EV 1 EV 2
COM
SETTINGS AND ADJUSTMENTS (fig. 3)
All adjustments must be made on the basis of the specific characteristics of the appliance.
Check inlet and outlet pressure using the pressure test points provided. After testing, carefully seal test points with
the provided screws. Recommended torque: 2.5 Nm.
Adjusting the outlet pressure
- Maximum pressure:
Power the modulating device with the correct voltage.
Turning the nut (B) clockwise (using a 10 mm spanner), the outlet pressure increases.
- Minimum pressure (adjust only after setting the maximum outlet pressure):
Turn off power supply to modulating solenoid.
Keeping nut (B) blocked using a spanner, turn the screw (A) clockwise to increase the outlet pressure.
6 After completing the adjustments:
• check the minimum and maximum pressure values: readjust if required
• Fit the protective cap C