Cranborne THI 5-25c, Инструкция по установке, наладке и обслуживанию

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OPERATION
3 - FUNCTIONS
- Boiler anti-freeze protection: When the boiler
temperature is below 5°C, the burner and the
heating circuit pump are switched on. When the
temperature increases and exceeds 15°C, the
burner stops and the pump continues to circulate
for 10 minutes.
- Anti-freeze protection for the installation: This
function uses the real outside temperature. It
adopts a different behaviour depending on the
temperature. If no measured outside temperature
is available, the function is blocked.
Different reactions can occur depending on the
outdoor temperature measured:
• If the outdoor temperature is less than or equal
to -5°C, the pumps operate continuously,
• If the temperature lies between -4 and 1.5°C,
the pumps operate for 10 minutes every 6
hours.
• If the outdoor temperature is over 1.5°C, the
pumps shut-down (no heating request).
Any domestic hot water request is given priority.
- Building anti-freeze protection:
The anti-freeze function of the building is a control
function (available with the QAA73 room sensor)
used to maintain the room temperature at a mini-
mum value, thus preventing the risk of freezing in
the building.
To provide a substantial degree of protection
against the development of pathogenic bacteria in
the domestic hot water tank during prolonged shut-
downs, the domestic hot water must be heated once
a week to a temperature above 60°C.
The anti-legionnella function is used for this purpo-
se. It heats the hot water storage tank once a week,
on Monday, after the first load, to a 65°C "anti-le-
gionnella" temperature.
When the heating mode ends, the heating circuit
pump remains on for a certain period (depending on
the settings used : QAA 73 setting : 544).
In hot water storage systems, when domestic hot
water heating ends, the heating circuit pump re-
mains on until the boiler temperature drops below
70°C. During this pump run-on period, the selector
valve remains in the “domestic hot water feed” posi-
tion.
If the heating circuit pump has not operated or if the
selector valve has not been activated for more than
about 24 hours, these elements are activated during
operating stops for approximately 5 seconds.
The boiler flow sensor in combination with the hea-
ting return sensor provide the overheat safety func-
tion.
There are two safety levels:
- if the first temperature value is exceeded, this is
signalled by a fault code on the display screen,
• TH
I 5-25 : 92°C ,
- if the second temperature value is exceeded
(100°C), it is signalled by an alarm code on the
display. The boiler switches to safety mode. The
boiler must be reset to be restarted.
If the temperature is exceeded, the heat present
must be evacuated through the fan and circulation
pump.
The two elements (fan and circulation pump) remain
on until the boiler shell temperature drops.
In the control algorithm, supervision of the tempera-
ture difference
D T between the flow and return re-
sults in the shutdown of the burner if D T is above
56°C.
3.1 - Anti-freeze function
3.2 - Anti-legionnella function
3.3 - Pump run-on after the end of heating
3.4 - Pump kick or selector valve kick
3.5 - Boiler overheat protection