Technical documentation
Technical documentation
STZS ed. 06/03
20
ZEUS SUPERIOR
LOW-VOLTAGE CIRCUIT
SAFETY DEVICES AND CONTROLS
Central-heating sensor
(NR)
Allows the modulation board to detect the temperature of the primary
circuit water flow.
If this sensor stops working, burner operation stops both in central-
heating and d.h.w. modes.
It is positioned at the outlet of the main exchanger.
Sensor NTC
10 kohm 25 ºC
Control zone unit (CZ)
(external optional)
Permits boiler operation with 3 area valves /external pumps controlled
by respective room thermostats.
Zone 1 is controlled
(times/temperatures)
by means of the CAR
(if
fitted).
See control unit
zone operation
Domestic hot water sensor
(NB)
This enables the modulation board to detect the temperature of the hot
water in the storage tank.
Its failure stops burner operation in domestic hot water phase.
It is inserted inside a bulb holder in contact with the external wall of
the cylinder.
Sensor NTC
10 kohm 25 ºC
External sensor (NE)
(external optional)
Detects external temperature and enables the modulation board to
change the system flow temperature according to outside temperature.
Sensor PTC
1 kohm 25 ºC
Flue pressure switch
(SV)
This acts on the modulation board and enables burner operation when
flue expulsion occurs correctly.
If this is closed with the fan off, the ignition cycle will not start.
2-position switch
Pump pressure switch
(SP)
This acts on the modulation board and permits interrupting power to
the control unit in the event of there being no circulation in the boiler
circuit.
Double-contact
switch
Remote control (CAR)
(external optional)
Permits remote control of boiler
iSUM/WINT switch, temperature
adjustment and indication, alarm display, reset, etc.)
and acts as a
weekly chrono-thermostat.
Together with the external sensor (NE), allows the modulation board to
change the system flow temperature according to need.
See Remote
Friend Control
operation (CAR
)
Room thermostat (TA)
(external optional)
This enables operation in central heating phase when the room
temperature is below that required.
In case of CAR installation, the room thermostat must be disconnected
without resetting the pre-existing jumper P1.
Double clean-
contact switch
LOADS
Display board
This displays burner operation
(orange LED),
operation in d.h.w. phase (
green LED)
and in
central-heating or antifreeze phase
(green LED
) on the control panel.
By means of a dispaly, it indicates the temperature of the boiler, the temperatures set for
d.h.w. and central-heating and the error codes
(see modulation board operation).
Modulation coil (MOD)
This is powered by the modulation board with variable direct current.
It permits changing gas pressure to the burner.
