Digital Inputs; Safety Loop X3-04; Flange X3-03; Inputs For External Controller (On/Off) X5-03 - Siemens LMV5 Series Basic Documentation

SAFETY LOOP
X3–04
FLANGE
X3–03
Inputs for external
controller
(ON/OFF)
X5–03
Note
2 inputs (ON / OFF or
STAGE2 / STAGE3)
( )
2 3
X5–03
Siemens Building Technologies
HVAC Products

4.1.1 Digital inputs

This input serves for including the safety loop. The special feature of this input is that all
signal source contacts connected in series here directly switch off the power supply to the
fuel valves and the ignition.
Typically, the following contacts are included in the safety loop:
External burner switch ON / OFF
−
Safety limit thermostat / safety pressure limiter (SLT / SPL)
−
External temperature limiter / pressure switch, if required
−
Water shortage switch
−
End switch burner flange (component of safety loop)
−
For the diagnosis, these signal source contacts are combined for delivering the «Safety
loop» message. If no signal is received, the burner will at least be shut down. What
follows is a number of repetitions that can be parameterized.
Parameter:
SafetyLoop
When the external control loop is closed, the signal from the integrated controller (if
present) is used to deliver the internal «Heat demand» information to the input.
There is a demand for heat when this external controller signal is present and – if
−
present and configured – there is a demand for heat from the internal load controller
or the building automation system
When there is no more demand for heat, the burner will be shut down. Depending on
the parameterization, the fuel valves will either be shut the moment the period of time is
completed by the timer, or after the MIN load is reached → Part load shutdown. In
operation with the internal load controller or with load control, the input can be
deactivated via a building management system. This means that a wire link at this
controller input is not required. In operating mode 1 (ExtLR X5-03), the input is always
active, deactivation is not active → Operating modes with load controller.
Parameter:
InputController (activated / deactivated)
1)
(Parameter text) in Italics = text displayed on the
The input is also valued with manual operation burner ON / OFF!
This input serves for the connection of an external controller with contact outputs. The
input is only active when configured as «External load controller».
Parameter: LC_OptgMode (ExtLC X5-03)
2 operating modes are possible. The one active depends on the parameterization of the
fuel / air ratio control system.
a) Parameter:
Operation Mode (Two-stage / Three-stage)
Multistage operation can be accomplished by using additional thermostats / pressure
switches.
Input « » activates stage 2.
2
Input « » and input «
3
b) Parameter:
Operation Mode (Modulating)
The burner's output can be increased or decreased by means of a 3-position step
controller output with 2 relays.
«▲» increases the output
«▼» decreases the output
If none of the 2 inputs is active, the burner's output is maintained at a constant level.
The shortest permissible positioning step is about 100 ms.
Basic Documentation LMV51...
4 Burner control
» activate stage 3.
2
1)
AZL5...
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CC1P7550en
01.10.2003