Fan Relay; Pump Relay; Safety Devices - Immergas EOLO Mini Technical Documentation Manual

Technical documentation

FAN RELAY

PUMP RELAY

REQUEST RELAY
V/G RELAY
Domestic hot water
potentiom. (D.H.W.)
D.h.w. modulation switch
(JP2)
Gas selectror (JP1)
Heating adjustmentr
(C.H.)
Heating power trimmer
(C. heating POWER)
Heating timer selector
(JP3)
Soft ignition trimmer
(IGN. POWER)
Circulator antiblock
Delivery overheating
ventilation
(from serial number 2238341)
No ignition block
No water /no circulation
(from serial number 2238341)
STEME ed 07/03
This is a single-pole relay that controls the fan (MV), which is excited when fan operation
is required.
This is a single-pole relay for controlling the pump (MP).
It is excited when operation is required.
This is a single-pole relay which is excited when the burner has to be ignited.
By means of its contact, the adjustment board ignition circuit is controlled.
This is a single-pole relay that is excited by the ignition circuit to energise the main gas
valve coils (VG).
ADJUSTMENTS
For setting the temperature of the hot water.
With a flow of 8 litres/min and an inflow temperature of 15°C, d.h.w. temperature can be set
between 32 ºC to 57 ºC.
For changing modulation during the d.h.w. phase by engaging burner
switch-off (opening of REQUEST RELAY) when the set temperature
is exceeded.
Depending on its position, it adapts the modulation parameters
for the gas for which the boiler is set (natural gas / LPG)
For setting the temperature of the water for heating between 38 ºC to 85 ºC.
For regulating output during the heating phase and adapting this to system requirements
(from min up to max set on gas valve)
Every time the unit switches off after achieving set temperature
during heating phase, a delay of 3 min/30 s is engaged until
subsequent ignition for the same request.
For regulating power to the modulation coil and consequently the pressure of the gas to
the burner during ignition (from min. up to 2/3 of max set on valve)

SAFETY DEVICES

With the main switch (IG) in SUMMER or WINTER position, the circulator (MP) is
operated for 30 seconds after 24 hours of inactivity.
To prevent the heat exchanger from overheating, if the temperature of the primary circuit
detected by NTC heating sensor (NM) exceeds 97 ºC, the fan (MV) is started until the
temperature has dropped to 93 ºC.
If, within 10 seconds from the start of the ignition cycle, the detection electrode (E3)
fails to detect the presence of a flame on the burner, boiler operation is stopped.
To start the appliance again, the main switch (IG) will have to be temporarily returned
to RESET position and a central-heating request made.
The tripping of the safety switch is indicated by the lighting up of led LD2 (red).
To prevent the water-gas exchanger from overheating, when the NTC heating sensor (NM)
detects an increase in temperature of over 5 ºC per second (pump stopped, system cocks
closed, etc) the burner is turned off.
The tripping of the safety device is indicated on the control panel by the lighting up of led
LD2 (red) and the flashing of led LD1 (yellow).
27
Technical documentation
off = set-point
switch-off
on = limit-temperat.
switch-off
off = natural gas
on = LPG
off = 30 s
on = 3 min
EOLO MINI