Operation of the pressure switch in pellet generators

The pressure switch must be connected to the silicone tube via the P1 fitting, which is the external one.
The electrical connection must be made on contacts 1 and 2, as indicated in the technical manual, corresponding to the terminals arranged in parallel (see figure shown in the manual).

The pressure switch mainly consists of two components: a diaphragm and a microswitch.
The diaphragm is housed inside a casing where the only external connections are the two fittings for the tube:

• P1 for pressure operation;
• P2 for vacuum operation.

MORETTI DESIGN products operate in pressure mode.

In the center of the diaphragm, there is a mechanical system that, depending on its movement, opens or closes the microswitch contact.
The latter has three terminals:

• a common (COM),
• a normally open contact (N.O.),
• a normally closed contact (N.C.).

Since the system works under pressure, the electrical connection must be made on the normally closed contact (N.C.).
In this configuration, the contact opens only when the internal pressure of the pressure switch reaches or exceeds 60 Pa.

This check should be performed already during the first ignition of the device.

It is recommended to always have the technical manual available during installation and maintenance phases. Alternatively, the document can be downloaded from the reserved area of the official MORETTI DESIGN website.