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Using the appropriate adapters, the LGA... can replace their predecessor types LFI7... and LFI5... in terms of function and size (refer to «Ordering»). LGA41.173A27 and LGA52.171B27 are suited for use with direct-fired air heaters. Siemens Building Technologies CC1N7418en HVAC Products...
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During the startup sequence, terminals 9 and 6 carry voltage and may not be used as auxiliary terminals LGA63... • Connect the load controller of 2-stage burners to terminal 5 in series with «BV2» 2/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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No air pressure signal during «t1» (only No startup with LGA52... / LGA63... with fan) Air pressure failure during operation Shutdown (only with LGA52... / LGA63... with fan) 3/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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• Undervoltage threshold: AC 178 V ±10 V Only with • LGA63.191A27 «TSA»: Smaller tolerance band • Flame signal amplifier: Higher sensitivity, for typical applications with pilot flames 4/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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For increasing the height of the LGA... to that of the LFI1... or LFI5... RC unit (for the supervision of ionization currents in networks with nonearthed neutral conductor) ARC 4 668 9066 0 5/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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5 µA Possible detector current max. 100 µA Length of detector cable max. 20 m (separate cable) Required insulation resistance between min. 50 MΩ ionization probe with its cable and ground 6/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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The amplifier is designed such that it only responds to the DC current component of the flame signal, thus ensuring that a short-circuit between ionization probe and ground cannot simulate a flame signal (since in that case, AC current would flow). 7/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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Ionization probe Safety limit thermostat Flame relay External primary fuse Built-in lockout warning lamp Electro-thermal timer Air pressure switch (bimetal system) with contacts «tz» Limit thermostat Ignition transformer Not monitored to EN 298 9/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...
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Commencement of startup sequence Operating position Time of flame establishment Controlled shutdown by «R» Prepurge Postignition Preignition time Interval «BV1 – BV2» t3´ Preignition time from the start of «TSA» Ignition safety time 10/11 Siemens Building Technologies CC1N7418en HVAC Products 08.04.2004...