Retrofit Challenges
Distribution retrofits in operating buildings face three constraints: (1) limited downtime windows — typically 2–4 hours per day; (2) existing infrastructure cannot be easily disturbed; (3) budget pressure to defer capital expenditure.
Industrial Bluetooth is uniquely suited to address all three, because no signal wiring is required between cabinets.
System Architecture
Three tiers: (1) RN-BT series Industrial Bluetooth meters at each metering point; (2) RN-IBS-100 IoT base station (one per 32 meters) aggregating data via Bluetooth Mesh; (3) cloud or on-premise energy management platform with web dashboard and mobile app.
Device Selection
For most retrofits, the RN-BT series three-phase meter with direct connect up to 80 A covers 80% of circuits. For higher-current circuits (e.g. main incomer), CT-input variants are available. For single-phase lighting circuits, the SP variant saves cost.
Commissioning Workflow
A two-person team can commission up to 80 meters per day. The flow: (1) power down the circuit; (2) install the meter in the existing cabinet; (3) power up; (4) scan QR code with the app; (5) confirm signal strength and binding. Total per-meter time: 15 minutes including paperwork.
Cost Comparison
For a 100-point retrofit: Traditional wired EMS ¥86,000 materials + ¥24,000 labour = ¥110,000. Industrial Bluetooth EMS: ¥28,000 meters + ¥3,600 base stations + ¥6,000 labour = ¥37,600. Saving: ¥72,400, or 66%.
Time to Online
Wired retrofit: 30 days from contract to data online. Industrial Bluetooth retrofit: 8 days from contract to data online, mostly because cabling and conduit work is eliminated.
Long-Term O&M
OTA firmware updates and remote diagnostics keep ongoing maintenance costs low. Over a 5-year horizon, the Industrial Bluetooth approach typically saves an additional 30–40% on O&M versus wired alternatives.