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Siemens Building Technologies  Basic Documentation LMV5...  CC1P7550en 
HVAC Products  4 Burner control  13.08.2004 
 
4.1.2 Digital outputs 
 
Safety-related outputs, type SI 
These contacts are read back by the microcomputers with the help of a contact feed-
back network (CFN) and then monitored for correct positions. 
 
Non-safety-related outputs, type No-SI 
These outputs are not monitored by CFN and, for this reason, can only be used for 
non-safety-related actuating devices are actuating devices that are secured in some 
other form (e.g. fans, oil pump / magnetic clutch, alarm). 
 
A signal lamp or horn can be connected to this output. 
The output will be activated when the unit is in the lockout position (Phase 00). 
This output can also be used to signal start prevention 
→ signaling of start preventions 
An active alarm output can be manually deactivated. Deactivation remains active until a 
lockout reset or a system reset occurs, or up to the next startup. Then, the alarm will be 
activated again. Deactivation only applies to the alarm output, lockout or start preven-
tion continue to be active. 
 
Parameter:  Alarm act/deact (activated / deactivated) 
 
This output is used for controlling a fan power contactor (200 VA). When changing to 
the lockout position, the fan continues to run for an adjustable period of time. 
 
Parameter:  PostpurgeLockout 
 
When → continuous purging is activated, the fan runs in all phases. This mode func-
tions only when using an APS relieve valve which, in Phase 21, ensures that the fan 
pressure switch does not sense any pressure, thus facilitating checking. 
 
Parameter:  ContinuousPurge (activated / deactivated) 
 
This output is used for connecting ignition transformers or electronic ignitors. 
When firing on gas, ignition is switched on just prior to «TSA1» in Phase 38. 
 
Parameter:  PreIgnitionTGas 
 
When firing on oil, there is choice of short preignition as with gas operation and long 
preignition. In the case of long preignition, ignition will be switched on when the fan 
starts to run in Phase 22. 
 
Parameter:  PreIgnitionTOil 
Parameter:  IgnOilPumpStart (on in Ph38 / on in Ph22) 
 
These outputs are used for connecting the oil valves in accordance with the selected 
fuel train. → Fuel trains, → sequence diagrams. 
 
Parameter:  FuelTrainOil (LightOilLO / HeavyOilHO / LO w Gasp / HO w Gasp) 
 
  (light oil with gas pilot and heavy oil with gas pilot may only be used in 
connection with Gp2) 
 
These outputs are used for connecting the gas valves in accordance with the selected 
fuel train. → Fuel trains, → sequence diagrams. 
 
Parameter:  FuelTrainGas (DirectIgniG / Pilot Gp1 / Pilot Gp2) 
 
Alarm output,
  
type No-SI 
X3–01 
Output fan, 
type No-SI 
X3–01 
Output ignition, 
type SI 
(IGNITION) 
X4–02 
Outputs valves-oil , 
type SI 
(V...) 
X8–02, X8–03, 
X7-01, X7-02 
Outputs valves -gas, 
type SI 
(V..., SV, PV) 
X9–01