Baxi LUNA HT 1.850 Installers And Users Instructions page 22

- Exchangers pressure drop
Graph 1
The minimum ga boiler water flow, with at least 1 - 1,5 bar, must be as follow:
Minimum water
LUNA HT
flow rate
Model
1.850
1.1000
13.2 DESCRIPTION OF THE ELECTRICAL CONNECTIONS TO BOILER TERMINAL BOARD M2
Turn the control box downward to access terminal board M2 used for the electrical connections by removing the two
protective covers (see figure 9).
Terminals 1-2: connection of SIEMENS model QAA73 temperature regulator supplied as accessory. Connection polarity
is irrelevant.
The jumper fitted across the "TA" terminals 3-4 must be removed.
Read the instructions supplied with this accessory for correct installation and programming procedures.
Terminals 3-4: "TA" room temperature thermostat connection. Thermostats with integral accelerator resistor must no be
used. Check that there is no voltage across the ends of the two thermostat connection wires.
Terminals 5-6: "TP" floor temperature thermostat connection (commercially available device). Check that there is no
voltage across the ends of the two thermostat connection wires.
Terminals 7-8: connection of SIEMENS model QAC34 outdoor temperature probe supplied as accessory.
Read the instructions supplied with this accessory for correct installation procedures.
Terminals 9-10: connection of domestic hot water precedence temperature sensor supplied as accessory for connecting
heating-only boilers to an external water heater.
13.3 CONNECTING THE QAA73 ROOM TEMPERATURE REGULATOR.
The SIEMENS model QAA73 room temperature regulator (optional accessory) must be connected to terminals 1-2 of
terminal board M2 in figure 9.
The jumper across terminals 3-4, provided for connection of a room temperature thermostat, must be removed.
The settings of the domestic hot water temperature and domestic hot water production schedule must be made using
this device.
The timed program of the central heating circuit must be set on the QAA73 if there is a single zone, or in relation to the
zone controlled by the QAA73 device.
The timed program for the central heating circuit of the other zones can be set directly on the boiler control panel.
See the instructions provided with the QAA73 room temperature regulator for the user parameter programming proce-
dure.
INSTRUCTIONS PERTAINING TO THE INSTALLER
Water flow rate
with Δt=20°K
l/h l/h
1900 3700
2100 4300
WATER FLOW RATE (l/h)
22
910.024.1 - EN (AUS)