WiFi + Bluetooth Connectivity
WiFi cloud communication for remote operation, with Bluetooth CIU connection for local recharge and data access.
DDSY/U353 is a single-phase two-wire prepayment keyboard meter (wall-mounted) with WiFi and Bluetooth communication. It features a built-in magnetic latching relay for pay-before-use, remote meter reading, remote recharge, remote balance clearing, overpower tripping and automatic tripping on balance exhaustion. CIU can connect via Bluetooth for data viewing and token entry. Class 1.0 accuracy.


WiFi cloud communication for remote operation, with Bluetooth CIU connection for local recharge and data access.
Class 1.0 accuracy with pay-before-use metering for residential and commercial prepayment applications.
Supports remote recharge via platform/app and 20-digit token input for offline top-up.
Built-in relay supports prepaid load control, remote switching and automatic disconnection after credit exhaustion.
Provides overload, overvoltage and undervoltage protection with automatic relay control.
Bluetooth-enabled CIU connection allows remote data viewing and token input without direct meter access.
| Voltage | 220 V |
| Frequency | 50 Hz |
| Rated current | 5(60) A |
| Start current | 0.4% Ib |
| Pulse constant | 1000 imp/kWh |
| Power consumption | < 2 W / < 10 VA |
| Active energy accuracy | Class 1.0 |
| Communication interface | WiFi + Bluetooth + RS485/IR |
| WiFi | 2.4 GHz band, YTL-BUS protocol, cloud connectivity |
| Bluetooth | CIU connection for remote data viewing and token entry |
| RS485/IR | Parameter setting and firmware upgrade |
| LCD display | 6+2, automatic scrolling |
| Metering function | Measures voltage, current, active/reactive power, frequency, power factor, total active/reactive energy |
| Prepaid function | Pay-before-use, remote recharge, remote meter reading, remote balance clearing |
| Recharge | 20-digit token entry or APS app remote recharge |
| Load control | Built-in magnetic latching relay: overpower tripping, auto tripping on balance exhaustion |
| Protection | Overload, overvoltage, undervoltage protection |
| Anti-tamper | Open cover detection, power theft status codes |
| Operating temperature | −20°C to +70°C |
| Relative humidity | < 75% |
| Applicable standards | IEC 62052-11 / IEC 62053-21 / IEC 62055-41 / GB/T 17215.321 / GB/T 17215.301 |
DDSY/U353 is a single-phase two-wire prepayment keyboard meter (wall-mounted) with WiFi and Bluetooth communication. It features a built-in magnetic latching relay for pay-before-use, remote meter reading, remote recharge, remote balance clearing, overpower tripping and automatic tripping on balance exhaustion. CIU can connect via Bluetooth for data viewing and token entry. Class 1.0 accuracy.
WiFi (2.4 GHz, YTL-BUS) for cloud connectivity, Bluetooth for CIU connection, and RS485/IR for parameter setting and firmware upgrade.
Remote recharge via APS prepayment system/app, or manual 20-digit token entry on the keyboard when signal is poor.
Complies with IEC 62052-11, IEC 62053-21, IEC 62055-41 and related standards.
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