The Siemens QRB4A-B050B70 is a normal-sensitivity yellow-flame detector with a 50 cm cable and a 68 mm black housing. This complete type reference identifies the version supplied without a soft plug, flange or clamp.
Product Specification
- Normal sensitivity; black 68 mm detector housing.
- Fixed 50 cm cable with 70 mm stripped ends and ferruled conductors.
- Two-core stranded copper cable, 2 × 0.75 mm².
- Supplied without a soft mounting plug, flange or clamp.
- Frontal and 90-degree lateral flame viewing.
- IP54 housing protection; electrical connections are excluded.
- Safety class II; operating ambient temperature −20 to +60 °C.
- Maximum rated voltage: 10 V; maximum permissible detector cable length: 3 m.
- Maximum spectral sensitivity: approximately 540 nm.
Control Compatibility
For Siemens LMO, LMV2 and LMV3 oil burner controls in intermittent operation. LME7 and LME8 combinations are available on request. The QRB4 signal is polarity-sensitive: the black lead is positive and the blue lead is negative.
Model Comparison
QRB4B-B050B70: The QRB4B counterpart has high sensitivity and a red housing; both versions use a 50 cm cable without mounting fittings.
