Description
Description :
Before performing any wiring changes in the connection area of the LOA…, the burner control must be completely isolated from the mains supply
• Ensure protection against electric shock hazard by providing adequate protection when mounting the burner control
• Check wiring and all safety functions
• Press the lockout reset button only manually, without using any tools or pointed objects
• Fall or shock can adversely affect the safety functions. Such units may not be put into operation, even if they do not exhibit any damage.
Installation notes • Installation and commissioning work may only be carried out by qualified staff
• Observe the permissible lengths of the flame detector cables; refer to data sheets 7714 (QRB…) and 7716 (QRC…)
• Always run ignition cables separately while observing the greatest possible distances to the unit and to other cables
• Do not mix up live and neutral conductors.
Functions
Whenever a fault occurs, the supply of fuel will immediately be shut down. With every lockout, the control outputs will be de-energized in less than one second, while terminal 10 («AL») for remote lockout indication receives voltage. The LOA… can be reset no earlier than approx. 50 seconds after lockout. No flame signal may be present during the pre-purge time. If, however, a signal is delivered during this period of time, the LOA… locks out on completion of the pre-purge and safety time, and there will be no release of oil. An erroneous flame signal can be caused by – premature establishment of the flame due to a leaking oil valve – extraneous light – a short-circuit in the flame detector or flame detector cable – faults in the flame signal amplifier, or similar Exception: With LOA25… / LOA28…, there will be no lockout, but burner startup will be prevented until the premature flame signal is no longer present. This means that the LOA25… / LOA28… may be used only where the requirements of EN 230 need not be satisfied. If, at the end of «TSA», there is no flame signal, the LOA… will immediately lock out. If, with the LOA25… / LOA28…, there are flame signal failures of short duration during «TSA» and «t4», the ignition transformer will automatically be switched on again. The total duration of the repeated ignition attempts equals «TSA» (10 seconds). On flame failure during operation, the LOA… will immediately shut down the fuel supply and automatically make a restart attempt (repetition). If flame failure occurs on completion of «t4», nearly the complete startup sequence will be repeated. With burner controls featuring undervoltage detection, an additional electronic circuit ensures that if mains voltage drops below about 165 V, burner startup will be prevented, or – without opening the oil valve – lockout will be triggered. Indications The fault position is indicated with the lamp integrated in the lockout reset button. Only with LOA36… Indication of the flame strength (green LED) is used for checking the flame signal. This LED must be lit to ensure reliable burner operation. If the green LED flickers or extinguishes during burner operation, the light conditions at the burner are inadequate, caused by dirt for instance. Only with LOA36… If the contact of the temperature controller is closed, the orange LED is lit, indicating the beginning of the oil pre-heater’ s heating up phase (if present). Control sequence in the event of fault Extraneous light / prem
