Anti-Freeze Functions; Hydraulic Separator - Sime D Serie Manual Del Usuario

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A.C.S. preparation program
There is the possibility of switching between three different prescri-
bed A.C.S. values, in order to attain optimum adjustment to the A.C.S.
requirement. Moreover, the A.C.S. preparation can be enabled or
disabled by modifying parameter n° 12.
a) Push the line selection button to select line 81.
b) Push the + / – buttons to select the A.C.S. preparation program.
Setup range U/M
0... 1 Increment
The A.C.S. can be heated according to different timing programs,
depending on the selection you made.
Input values:
0 24 hours a day
1 According to the local heating programs, with one–hour
advance.
– Setting value 0 : 24 hours a day
The A.C.S. temperature is always kept at the setpoint value of the
A.C.S. temperature, irrespective of the timer programming.
– Setting value 1: According to the local heating programs, with
one–hour advance
For the A.C.S. preparation, the selected heating program is taken into
consideration. The switching points will be set one hour in advance, so
that the actual A.C.S. temperature will be obtained as necessary. The
switching–off will occur at the same time of that of the heating.
7 ANTI–FREEZE FUNCTIONS
The system has 5 types of anti–freeze functions:
1) Installation anti–freeze function
2) Room temperature anti–freeze function
3) Heating circuit anti–freeze function
4) Boiler anti–freeze function
5) Hot water tank anti–freeze function.
1) When the function is active (Parameter n° 25 "costruttore" = 1),
the heating circuit pump is activated according to the attenuated
external temperature, even when there is no need of heat, fol-
lowing the table below:
Attenuated external temperature
–4°C
–5°C... 1,5°C ON for 10 minutes every 6 hours
1,5°C
2) This function prevents the room temperature from sinking below
the value set at the "utente" Parameter n° 15. It is the anti–free-
ze function for the building. A room unit is required.
Default value
1
Pump
Continuously ON
Continuously OFF
3) The anti–freeze protection for the heating circuit is active in cir-
cuits working with pumps or mixing valves. If the circuit delivery
temperature sinks below 5 °C, a heat requirement of 10 °C is
generated.
This causes the pump circuit to start operating. If there is a
mixing valve, the valve, too, will be opened to the desired position.
4) The boiler anti–freeze function is activated when the boiler deli-
very feeler senses a temperature lower than 6 °C.
5) The anti–freeze temperature for the A.C.S. is set at 5 °C and is
always active.
8

HYDRAULIC SEPARATOR

When in the same installation there are both a primary circuit for hot
water production, equipped with its pump, and a secondary circuit for
hot water distribution with one or more distribution pumps, there can
be special operating conditions of the installation, causing the pumps
to interact and creating anomalous differences in the flow rate and
in the circuit heads. The hydraulic separator creates a reduced flow
resistance zone and this allows the primary and secondary circuits
connected to it to be independent.
The advantages of using a hydraulic separator can be outlined as follows.
– The flow in one circuit does not create a flow in the other one, if the
flow resistance in the shared length is negligible.
– The flow rate in the circuits depends solely on the flow rate cha-
racteristics of the pumps, preventing a mutual influence due to
their in–series connection.
– The hot water production circuit has a constant flow rate and the
distribution circuit has a variable flow rate, which is a characteri-
stic feature of the modern air–conditioning systems.
We won't delve deep into the problem of the temperature differences
caused by separators in the heating systems when the primary and
the secondary circuit have different flow rates. We are rather pre-
senting a criterion for calculating the size of the hydraulic separator
according to the thermal power of the primary circuit, which is the
sum of the thermal power values of all the single boilers.
The hydraulic separator we are presenting has a bleed valve to elimi-
nate the air and an emptying valve to eliminate the sedimented impu-
rities, assuming there is a 15 °C difference between the delivery tem-
perature and the return temperature of the boiler circuit.
Valvola di sfiato
D
Valvola di svuotamento
83