HYDRAULIC CONFIGURATION 4 (four) SCHEME 3

SCHEME 3 – Thermal storage system (buffer) with single probe (S1) and secondary plant circulator (P2)

The Scheme 3 of Hydraulic Configuration 4 includes:

• buffer with temperature probe S1 positioned in the central area;
• secondary circulator P2 dedicated to the plant circuit (users);
• primary circulator P1 integrated into the generator.

The system management occurs through control of the storage temperature (S1) and separate activation of the plant circulator P2.

Control unit parameters

Operational notes:

P26=4   Select hydraulic configuration 4

P73= 9  Enable buffer probe S1 (input IN10)

Ih58= 2 °C  Buffer thermostat hysteresis (Value subtracted from buffer setpoint to determine the generator restart threshold in standby condition)

Th59=53 °C  Activation threshold for secondary circulator P2 (output A2 – 230 V ~ 50 Hz)

D23= 4°C default  Additional delta to boiler setpoint for switching from modulation to standby at the end of time T43 (10 s default) 
It is recommended to set the boiler/stove temperature slightly higher than the buffer temperature

Adjustment note

It is recommended to set the stove/boiler setpoint temperature higher than the buffer setpoint to ensure an adequate thermal gradient for charging the storage.

Connecting buffer temperature probe (S1)

Stoves with rear connectors:

• TECNIKA TURBO GLASS, TECNIKA FOR HOME, TURBO TOP, TURBO GLASS, PRESTIGE, EXCLUSIVE, TECNIKA EXCLUSIVE
• Probe S1 is connected to the control unit at output IN10 (Probe: NTC-10K; Moretti Article: MFSONDC)

Stoves without rear connectors:

• ALADINO, ELEGANCE, CLESSIDRA, ERGONOMIC, COMPACT, VISION, SLOT VISION, DOLBY
• Connect the S1 probe cables directly to the control unit at PIN 52 – PIN 53 GND (output IN10) (Probe: NTC-10K; Moretti Article: MFSONDC)

Connecting plant circulator (P2)

Stoves with rear connectors:

• TECNIKA TURBO GLASS, TECNIKA FOR HOME, TURBO TOP, TURBO GLASS, PRESTIGE, EXCLUSIVE, TECNIKA EXCLUSIVE
• The circulator P2 is connected to the control unit at output A2 (Moretti Article: MFR157AE)

Stoves without rear connectors:

• ALADINO, ELEGANCE, CLESSIDRA, ERGONOMIC, COMPACT, VISION, SLOT VISION, DOLBY
• Connect the P2 circulator cables directly to the control unit at PIN 16 (N) – PIN 18 (FON) (output A2) (Moretti Article: MFR157AE)

Check connection of buffer temperature probe

To verify the correct connection of the buffer temperature probe, proceed as follows:

1. Access the remote control.
2. Enter the User Menu.
3. Select the “Information” item.

With parameter P73 = 9, the temperature detected by probe S1 is displayed.

To change the buffer temperature, proceed as follows:

1. Access the remote control.
2. Enter the User Menu.
3. Select the “Thermostats” item.
4. Select the “Buffer” item.

In this section, it is possible to set the buffer temperature setpoint.

Operating logic

Buffer loading management (P1)

Probe S1 controls:

• generator ignition;
• power modulation;
• switching to standby mode.

The restart threshold is determined by:

Buffer setpoint – Ih58

If the temperature falls below this value, the generator reactivates.

Plant circulator activation (P2)

Parameter Th59 (53 °C default) defines the minimum stove/boiler temperature threshold for activation of the secondary circulator P2.

Activation condition

When the temperature detected by probe S1 is: ≥ Th59

the control unit enables output A2, powering circulator P2 and allowing heat distribution to the plant.

Deactivation condition

When the temperature falls below the set threshold (considering any internal hysteresis), circulator P2 is deactivated to avoid sending heat transfer fluid at insufficient temperature to the plant.

Overall functional logic

• P1 → manages storage loading
• P2 → manages plant distribution
• S1 → sole control of buffer temperature

This configuration allows:

• hydraulic separation between generator circuit and user circuit;
• better thermal stability of the plant;
• prevention of low temperature supply to terminals.

ROOM THERMOSTAT (R.T.) CONFIGURATION

The management of the Room Thermostat (R.T.) depends on the correct setting of parameters in the control unit.
An incorrect configuration may interfere with the buffer control logic and compromise the correct operation of the system.

The boiler ignition and shutdown control is managed by the buffer probe.

Configuration parameters

Functional description of parameters

• Parameter P99 – Contact logic

  Setting in SETTINGS: P99 = 1 (default) → input configured for thermostat with normally open (N.O.) contact

  Setting in SETTINGS: P99 = 0 → input configured for thermostat with normally closed (N.C.) contact

The selection must be consistent with the type of installed device.

•  Parameter A01 – Pump interaction 

Setting in SETTINGS: A01 = 3

The Room Thermostat acts on pump lock, interrupting the distribution of the heat transfer fluid to the plant upon reaching the set room temperature.
 

•  Parameter T45 – Enable R.T. management without time delay

Setting in TIMES: T45 = 0

Technical warning

Do not configure parameter A01 with values 0, 1, 2, or 4 when active buffer management is present.

In such configurations:

• boiler/stove ignition and shutdown are managed exclusively by the buffer probe;
• the R.T. must not directly intervene on the generator ignition logic.

An incorrect setting can cause:

• regulation conflicts;
• incorrect ignition/shutdown cycles;
• thermal instability of the system.

Parameter T45 – R.T. input timing

Set: T45 = 0

to enable the Room Thermostat function without additional time delays.

Any different values introduce delays that may affect the system's dynamic response.

• Correct operating logic (with buffer)

When thermal storage is present:

• The buffer probe manages generator ignition and modulation.
• The Room Thermostat manages only the enabling/disabling of the plant pump P2.
• The generator must not be directly controlled by the R.T.

This configuration guarantees:

• proper energy management of the storage;
• stability of stratification in the buffer;
• reduction of generator start-up cycles.