Siemens QRB1 detectors monitor the visible light from yellow-burning oil flames. They use a photoresistive sensing element and are designed for intermittent burner operation. The complete model code identifies the sensitivity, housing, cable and mounting arrangement.
Choose Your QRB1 Configuration
Start with the sensitivity specified for your burner control, then match the housing length and mounting. Cable length and the supplied fittings distinguish many otherwise similar references.
| Type | Sensitivity | Housing colour |
|---|---|---|
| QRB1A | Normal | Black |
| QRB1B | High | Red |
| QRB1C | High, selected | Blue |
Normal-Sensitivity Models
These QRB1A versions share a 50 mm housing, ferruled conductors and 70 mm stripped cable ends. The table separates cable length from mounting hardware.
| Model | Cable | Included mounting |
|---|---|---|
| QRB1A-A050B70A | 50 cm | None |
| QRB1A-A070B70A | 70 cm | None |
| QRB1A-A070B70A1 | 70 cm | 21 mm flange + clamp |
| QRB1A-A070B70A2 | 70 cm | 36 mm flange + clamp Specifications & price → |
| QRB1A-A150B70A | 150 cm | None |
High-Sensitivity Models
QRB1B-A070B70A retains the 50 mm housing and 70 cm cable of the corresponding QRB1A version. QRB1B-C036B40A has a longer detector housing and a shorter cable.
| Model | Housing | Cable / stripped end |
|---|---|---|
| QRB1B-A070B70A | 50 mm | 70 cm / 70 mm |
| QRB1B-C036B40A | 105 mm | 36 cm / 40 mm |
Both high-sensitivity references above have ferruled conductors and are supplied without a flange, clamp or mounting plug. For another configuration, include the full model code in your inquiry.
Mounting and Model Suffixes
- Flange mounting: the QRB1 references ending in A shown above exclude the flange and clamp. A1 includes a small flange with 21 mm hole spacing; A2 includes the large 36 mm flange and a clamp.
- Plug mounting: QRB1 versions ending in B use a soft mounting plug instead of the flange and clamp.
- Cable: fixed two-core cable, 2 × 0.75 mm². The model table gives the visible cable length, separate from the stripped-end length.
Detection and Control Compatibility
- Photoresistive sensing with peak spectral sensitivity at approximately 600 nm.
- Frontal or 90-degree lateral flame viewing.
- IP40 protection and an operating ambient temperature of −20 to +60 °C.
- Siemens lists combinations with LAL, LME7, LMO, LMV and LOA control families. The specific control determines the required sensitivity and permissible detector cable length.
QRB4 is a separate photodiode detector family. For its cable and plug configuration, see the QRB4B-B070B70B product page.
