Siemens LMU64 Series - 1.2 Features; Safety functions; Supervision; protective functions for the plant

11/171
Siemens Building Technologies Basic Documentation LMU54... / LMU64... CC1P7494en
HVAC Products 1 Overview 07.11.2002
1.2 Features
Below, the full functionality of the LMU... is described. For information on the scope of
functions of a specific unit, refer to the relevant version / configuration.
• Gas burner control conforming to EN 298 for intermittent operation
• Integrated boiler / burner control for space heating and DHW operation
• Sequence control depending on the boiler’s capacity: < 70 kW, 70 - 120 kW, or > 120 kW.
Boiler capacities up to about 600 kW can be handled (depending on the type of fan /
gas valve used)
• Integrated electronic (safety) limit thermostat
• Integrated limit thermostat function
• Direct ignition of the main flame by means of
− integrated single-pole high-voltage ignition (with the choice of single-electrode
operation)
− external AC 230 V ignition control (optional)
• Continuous (analog) ionization current supervision with optional indication of flame
intensity
• Gas valve control AC 230 V (RAC optional)
• Number of start repetitions can be programmed
• Quick startup (especially in connection with instantaneous DHW systems)
• Fan supervision
• Optimization of combustion (optional)
• Control of an AC 230 V fan (DC 24 V fan optional)
• Ignition load precontrol via speed readjustment
• Adaptive postpurge level of fan speed
• Load limitation (fan limitation by minimum / maximum speed and / or flame signal)
• Number of fan feedback pulses can be selected
• Flame stabilization time
• Boiler cycling protection via minimum boiler off time
• Dynamic switch-off differentials for space heating (Hz) and DHW (Bw) operation
• Pump and diverting valve kick
• Frost protection functions for the plant, the boiler, DHW and the room
• Water pressure supervision (pressure sensor with static and / or dynamic supervision,
contact for pressure switch, flow switch)
• Flue gas temperature supervision
• OCI420 clip-in for communication, LPB interface for ALBATROS system world
• AGU2.500 clip-in for additional heating circuit
• AGU2.51x clip-in function module
- inputs: NTC, 10 kΩ
digital input
0(4)...20 mA
DC 0...10 V
- outputs: max. 3 relays AC 230 V
Safety functions
Supervision / protective
functions for the plant
Auxiliary modules
(clip-in)