Beretta Ciao C.A.I User Manual

9
caldaie
CH
OUT IN
Gas solenoid valve opens the shutter proportionately to allow
slow burner ignition, automatically adjusted by
microprocessor. The boiler will then work at 75%capacity of
its maximum power for 15 min.; then it starts delivering
maximum power, if necessary, and modulating when tempe-
rature set on heating selector is reached. If, during the first
15 min., power necessary is lower than 75%, boiler modulates
below this value, without waiting 15 min. expiry.
When the temperature set is reached by heating selector, the
main board automatically updates power to system request.
If, also when idling, power supplied exceeds temperature
request, the main board switches off the burner, allowing it
to switch on again after 3 min. ± 10 s only, then it operates
idling for 2 more min.
To summarise, once the hot water tap is closed, in
« » WINTER position and when the room thermostat
signals for it, the working sequence is the following:
C.A.I. version
Room thermostat enabling
Circulator
Water pressure switch check
Burner
C.S.I. version
Room thermostat enabling
Circulator
Water pressure switch check
Quiescent safety pressure switch
Fan
Safety pressure switch enabled
Burner
1.6.4 Hydraulic operating principle in CH
(Fig. 1.25)
When request is set on CH side, circulator (1) is fed, generating
a depression on return (2).
The water, pushed into primary exchanger (3) by circulator,
flows along the connection ramp to system delivery.
System pressure greater than 0.45 bar closes the contact of the
water pressure switch and burner ignition is started.
During normal operating conditions, i.e. low-load-loss system
or water circulation exceeding 450 l/h, the automatic by-pass
(4) is closed and then making the water flow only towards the
system delivery.
On the contrary, if relevant load losses exist on the
system, the circulator unloads its head onto the by-pass
shutter surface (4); the by-pass connecting return and
delivery by duct and internal recirculation is obtained, to
be added to water coming from system return.
Fig. 1.25
1.6.5 Electric operating principle in CH
(APPENDIX - E pages 81, 82)
When selector is in CH « », with room thermostat
request, circulator is activated. By water pressure switch, proper
water pressure is checked and burner ignition is not enabled in
case of system pressure less than 0.45 bar.
- C.A.I. version
Now, if primary water temperature read by NTC sensor is
lower than temperature set on the control panel, ignition
starts up.
- C.S.I. version
Fan is activated and its movement generates vacuum and
pressure - repeatedly read by Venturi and pitot pipe - which
act on pressure switch. This pressure switch closes its
internal electric contact and enables opening of gas valve
operating devices; at the same time, it starts ignition by
appliance flame control.

Beretta Ciao C.A.I Specifications

General

Brand	Beretta
Model	Ciao C.A.I
Category	Boiler
Language	English