User Manual

13/33
Building Technologies CC1N7491.1en
03.04.2018
External system components
External system components are devices such as
∂ Ignition equipment
∂ Fan
∂ Gas valve
∂ Flow switch Hall sensor DHW
∂ Heating circuit pump
The external system components used must be approved by Siemens AG!
Functions
∂ Modulating control in both central heating (CH) and domestic hot water (DHW)
mode
∂ PID control of the boiler temperature
∂ PID control of the DHW temperature (DHW outlet temperature) (depending on the
type of LMU34)
∂ NTC temperature sensor on boiler flow pipe
∂ NTC temperature sensor on instantaneous DHW line or storage tank (depending
on the type of LMU34)
∂ NTC temperature sensor on DHW plate heat exchanger for the aqua-booster in-
stantaneous water heater (depending on the LMU34 type)
∂ Connection facility for a CH programmer / timer
∂ Connection facility for a non-safety-related flow switch (CH) or water pressure
switch
∂ Frost protection CH system (boiler only)
∂ Frost protection DHW (boiler only) (depending on the type of LMU34)
∂ Flame supervision by ionization
∂ Nonvolatile lockout in the event of loss of flame
∂ Nonvolatile lockout in case of high limit thermostat (TB) response
∂ Flue gas NTC temperature sensor input or flue gas thermostat input with non-
safety-related function
∂ Programmable fault response on flue gas failure: Volatile burner stop or nonvolatile
lockout
∂ Multitry ignition sequence
∂ Outside sensor input
∂ Integrated weather compensation of CH
∂ Pumps kick function and valves kick function
∂ 3 LEDs for status signals
∂ 2 x 7 segment red displays of temperature, faults and diagnostic data
∂ Auxiliary module AGU2.002 (depending on the type of LMU34)
∂ CH potentiometer and DHW potentiometer with additional service functions
∂ Control of fan speed (non-safety-related)
∂ Connection to PC tool interface OCI490 / OCI425 with corresponding software
ACS (laboratory use)
∂ OpenTherm (parameter settings for LMU34 via QAA73) (depending on the type of
LMU34)
∂ Control condensate pump (depending on the type of LMU34)