Siemens LMV5 Series Basic Documentation

Also see for LMV 5 Series: User manual Manual Technical instructions Quick start guide Manual

34/278Siemens Building Technologies Basic Documentation LMV51... CC1P7550enHVAC Products 4 Burner control 01.10.2003No-load voltage at terminal ION (X10–03, terminal 1) approx. UMainsNote: The ionization probe must be installed such that protection against electric shockhazard is ensured!Short-circuit current max. AC 0.5 mAMinimum detector current required DC 6 μA, display flame approx. 50 %Maximum detector current approx. DC 85 μA, display flame approx. 100 %Permissible length of detector cable(laid separately) 100 m (wire-earth 100 pF / m)The greater the detector cable capacitance (cable length), the lower the voltage at theionizations probe and, therefore, the lower the detector current. In the case of extensivecable lengths and high-resistance flames, it may be necessary to use low-capacitancecables (e.g. ignition cable).The electronic circuit is designed such that impacts of the ignition spark on theionization current will be largely eliminated. Nevertheless, it must be ensured that theminimum detector current required will already be reached during the ignition phase.If that is not the case, the connections of the ignition transformer on the primary sidemust be changed and / or the location of the electrodes also.No-load voltage at the QRB... terminal (X10–02, terminal 1) approx. DC 8 VMinimum detector current required(with flame) DC 30 μA, display flame 35 %Maximum permissible detector current(dark current with no flame) DC 5 μAMaximum detector current approx. DC 70 μA, display flame approx. 100 %Permissible length of QRB... detector cable(laid separately) 100 m (wire-wire 100 pF / m)A detector resistance value of RF < approx. 5 kΩ is identified as a short-circuit and, inoperation, leads to safety shutdown as if loss of flame had occurred.Measurement of the voltage at terminal QRB... during burner operation gives a clearindication: If voltage drops below 1 V, safety shutdown will probably occur.For that reason, before using a highly sensitive photoresistive flame detector (QRB1Bor QRB3S), it should be checked whether such a detector is really required!Increasing line capacitance between the QRB... terminal and mains live «L» adverselyaffects the sensitivity and increases the risk of damaged flame detectors due to mainsovervoltages.The separate laying of detector cables as specified in Data Sheet 7714 must beobserved.For indication of flame (on the AZL5...), observe the following general rules:The above percentage values are obtained when, for parameter «Standardize»(standardization of flame signal), the default setting is used.The accuracy of the display is a maximum of ± 10 %, depending on the tolerances ofthe components.It should also be noted that, for physical reasons, there is no linear relationshipbetween the display and the detector signal values. This is especially obvious withionization current supervision.For more detailed information, refer to Data Sheet 7714.IONIZATION (suited forcontinuous operation)NoteQRB... (for intermittentoperation only)Notes