Low-mount ceiling PIR motion sensor with a built-in daylight sensor, embedded Casambi and a 1-channel ON/OFF relay output. It detects movement across up to 8–10 m diameter at a typical 3 m ceiling height and flush-mounts in a 65 mm cut-out. Merrytek recommends it for offices, corridors and passageways. Detection area, hold time and daylight settings are adjusted wirelessly from the Casambi app.
Key Benefits
Passive infrared motion detection and a 0–1200 lux daylight sensor in one compact ceiling unit. Picks up people walking across up to 8–10 m diameter, at mounting heights from 2.5 to 6 m.
Switch a local load straight from the built-in ON/OFF relay, up to 1200 W resistive or 600 W inductive, while the same sensor triggers Casambi luminaires and scenes over Bluetooth.
Detection area (100, 75, 50 or 25%), hold time and daylight settings are adjusted in the Casambi app. Flush-mounts in a 65 mm ceiling cut-out; surface mounting needs Merrytek's separate surface-mount kit.
Technical Specifications
| Model | MSA246S IR B1 |
| Detection Technology | Passive Infrared (PIR) + daylight sensor |
| Max Detection Range | 8–10 m diameter |
| Radius at 3 m Height | 4–5 m tangential / 2–3 m radial (walking at 1 m/s, 25°C, 100% sensitivity) |
| Radius at 6 m Height | 4–5 m tangential / 2–4 m radial (walking at 1 m/s, 25°C, 100% sensitivity) |
| Mounting Height | 2.5–6 m (typical 3 m) |
| Detection Area | 100 / 75 / 50 / 25% (set in the Casambi app) |
| Supply Voltage | 220–240 VAC (rated 230 VAC) |
| Power Consumption | ≤ 0.5 W at 230 VAC |
| Output | 1× ON/OFF relay + Casambi BLE |
| Max Load | 1200 W resistive / 600 W inductive (single load; Merrytek recommends an AC contactor for larger loads) |
| Surge Protection | 2 kV (L/N, EN 61000-4-5) |
| Daylight Range | 0–1200 lux |
| Hold Time | Sensor 2 s + Casambi linger time (set in the app) |
| Bluetooth Range | Up to 40 m in open areas |
| Dimensions | Ø80 × 80.5 mm (body Ø63 mm) |
| Cut-out | Ø65 mm |
| Mounting | Ceiling flush mount (surface mount with separate kit) |
| Operating Temperature | -25°C to +50°C |
| Storage Temperature | -40°C to +80°C |
| Ingress Protection | IP20 (flush mounted) |
| Certifications | CE, RoHS |
Tell us your room sizes and ceiling heights and we will spec the right sensor layout for your installation.