Immergas NIKE Mini 24 Export Manual page 26

Technical Documentation
Electrical circuit.
Central heating phase.
(*) depending on the gas valve used, the main coils are powered
at mains voltage (SIT 845) or at mains voltage rectified by a
diode bridge (U1) housed in the valve connector (Honeywell
VK4105).
Working with the Room thermostat.
By selecting the (Winter), functioning mode with the
(S2) push button, the boiler is enabled to work in the central
heating mode.
When the room thermostat (S20) closes the integrated board
powers the boiler circulator (M1) by means of the K3 relay
and, with the deviation of the K1 relay contact, powers the
motor (M) of the 3-way valve (M30) which keeps working
until limit switch "1" opens when the central heating posi-
tion is reached.
The integrated board, enabled by the safety thermostat (E4)
and fumes thermostat (E6) and if the temperature measured
by the NTC delivery probe (B1) is below the value set on the
boiler's control panel, energises the request relay K2 that causes
the 2 contacts to close which allows the ignition cycle to start,
first of all triggering the ignition electrode (E1) and then both
the gas valve coils (Y1).
STNM ed 07/07
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Burner ignition is detected by the integrated board by means
of the ionisation electrode (E2).
Remote digital control operation.
By selecting the Winter functioning mode on the Remote
Digital Control (CRD) panel the boiler is enabled to work in
the central heating mode.
If the conditions detected by the CRD require ignition in the
central heating mode, the integrated board powers the boiler
circulator (M1) via the K3 relay and the burner is ignited as
described above.
NOTE: With each switching off when the temperature is
reached, the integrated board stops the burner working in the
central heating mode for a time equal that set with the board
parameters (see integrated board operation).
24
Technical Documentation
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NIKE Mini Export