🏠 Home → Equipment → DRY CONTACT RELAY
¶ Device Description
The ROSSMA IIOT-AMS DRY CONTACT RELAY meter-switch is designed for remote control of high-voltage industrial equipment (up to 30 kW) using commands received via LoRaWAN or NB-IoT wireless networks.
The device is equipped with a powerful relay output (switching up to 240V 10A) and four discrete inputs for monitoring equipment status and pulse counting.
Fig. ROSSMA IIOT-AMS DRY CONTACT RELAY meter-switch appearance
Equipment is registered in the register of the Ministry of Industry and Trade of the Russian Federation as equipment manufactured on the territory of the Russian Federation (Conclusion 48859/11 dated June 11, 2021).
¶ Application Areas
¶ Industrial Equipment Control
- Pump stations: remote switching of pumps on/off
- Ventilation systems: control of fans and air handling units
- Compressor equipment: remote start/stop of compressors
- Conveyor lines: control of conveyor electric drives
- Machines and production equipment: remote start/stop (up to 30 kW)
¶ Lighting Control
- Street lighting: on/off by schedule or sensors
- Industrial workshops: control of large area lighting
- Parking lots and territories: automation of lighting by time of day
- Emergency lighting: activation when sensors trigger
¶ Irrigation Control
- Automated irrigation: on/off of pumps and solenoid valves
- Parks and squares: remote control of irrigation systems
- Greenhouses: automated irrigation by schedule
- Farms: control of irrigation systems
¶ Equipment Status Monitoring
- Operation monitoring: tracking on/off status of connected equipment
- Alarm signals: monitoring of protective relays and sensors
- Operating hours counting: counting equipment operating time
- Pulse counting: counting work cycles (starts/stops)
¶ Technical Specifications
¶ Relay Output (Power Contact)
- Contact type: dry contact, normally open (NO)
- Switching voltage: up to 240 V AC
- Switching current: up to 10 A (resistive load)
- Switching power: up to 2400 W (at 240V AC) / up to 30 kW (via contactor)
- Load type: resistive, inductive (with snubber)
- Number of relay outputs: 1 (one)
- Switching life: more than 100,000 cycles
IMPORTANT: For switching inductive loads (motors, transformers), it is recommended to use an RC circuit (snubber) to protect relay contacts from arcing.
For high-power loads (>10 A): Use an intermediate contactor. The switch relay controls the contactor coil, which switches the power load (up to 30 kW).
¶ Discrete Inputs
- Number of inputs: 4 (four)
- Input types:
- 2 galvanically isolated inputs (IN1, IN2) — for connection to circuits with different potentials
- 2 regular inputs (IN3, IN4) — for connecting dry contacts to GND
- Input functions:
- Pulse counting (counting contact closures)
- Status monitoring (closed/open)
- Maximum input voltage: 30 V
- Contact type: normally open (NO)
- Bounce protection: software filtering
¶ Power Supply
- Supply voltage: 230 V AC, 50 Hz
- Built-in power supply: yes (switching power supply)
- Power consumption: 5 W (standby), 10 W (relay switching)
- Overvoltage protection: built-in
- Output for external devices: +5 V DC (up to 500 mA)
¶ LoRaWAN Wireless Communication
- Device class: A or C
- Frequency plan: RU868, EU868, IN865, AS923, AU915, KR920, US915, KZ865
- Activation method: ABP or OTAA (configurable), default ABP
- Receiver sensitivity: -138 dBm
- Radio range: up to 5 km in urban areas; up to 15 km in rural areas
- Transmitter power: 25 mW (default), maximum 100 mW
- Antenna type: internal
¶ NB-IoT Wireless Communication
- Frequency bands: B1/2/3/5/8/12/13/17/18/19/20/25/26/28/66/70
- Data rate: 25/20 kbps (single-tone) or 60 kbps (multi-tone) (DL/UL)
- Sensitivity: -138 dBm
- Radio range: up to 5 km in dense urban areas; up to 15 km outside populated areas
¶ Operating Characteristics
- Operating temperature range: -40…+70°C
- Relative humidity: up to 95% at +25°C (non-condensing)
- Atmospheric pressure: 84...106.7 kPa
- Protection degree: IP65
- Housing material: polycarbonate (UV resistant)
¶ Design and Dimensions
- Housing dimensions: 115×90×50 mm
- Weight: 250 g
- Mounting: DIN rail adapter or mounting loops for wall mounting
- Cable gland type: M16×1.5 (specified when ordering)
- Number of cable glands: 2-4 (depending on configuration)
¶ Capabilities
- Remote control of powerful equipment (up to 30 kW via contactor)
- Load switching up to 240 V 10 A AC
- 4 discrete inputs for equipment status monitoring and pulse counting
- 2 galvanically isolated inputs for connection to circuits with different potentials
- Wireless command transmission via LoRaWAN/NB-IoT
- Relay status reporting and input status to server
- Scheduled control (configured on server)
- Manual control via ROSSMA NETS web interface
- Automatic control by sensor readings (via server rules)
- Built-in 220 V power supply — no external power source required
- +5V output for powering external sensors and devices (up to 500 mA)
- Operating hours counting and on/off cycle counting
¶ Indication
The ROSSMA IIOT-AMS DRY CONTACT RELAY meter-switch has the following indicators:
- PWR (Power) — 220V power present
- RELAY — relay output status (on/off)
- IN1, IN2, IN3, IN4 — discrete input status
- LoRa — data transmission/reception via LoRaWAN network
- NET — NB-IoT network connection
- Success — successful command or data transmission
The meter-switch has a RESET button for device restart.
¶ Connection
¶ Power Equipment Connection Diagram
Option 1: Direct load connection (up to 10 A)
┌────────────────────┐
220V ────┤ ROSSMA DRY CONTACT │
│ RELAY │
L ─────┤ L (phase) │
│ │
N ─────┤ N (neutral) │
│ │
PE ─────┤ PE (ground) │
│ │
│ RELAY OUT: │
│ COM ──────┬───────┼──── Load (lamp, pump, <10A)
│ │ │
│ NO ───────┘ │
└────────────────────┘
└──── Neutral (N)
Option 2: Connection via contactor (for high-power loads >10 A, up to 30 kW)
┌────────────────────┐ ┌───────────────┐
220V ────┤ ROSSMA DRY CONTACT │ │ Contactor │
│ RELAY │ │ (30 kW) │
L ─────┤ L (phase) │ │ │
│ │ ┌────┤ A1 (coil) │
N ─────┤ N (neutral) │ │ │ │
│ │ │ ┌──┤ A2 (coil) │
PE ─────┤ PE (ground) │ │ │ │ │
│ │ │ │ │ Power │
│ RELAY OUT: │ │ │ │ contacts: │
│ COM ──────────────┼────┘ │ │ │
│ │ │ │ L ───── L1 ─┼──── High-power
│ NO ───────────────┼──────┘ │ │ load
└────────────────────┘ │ N ───── N ─┼──── (up to 30 kW)
│ │
│ PE ───── PE ─┼────
└───────────────┘
Recommendation: For controlling powerful electric motors (>3 kW), use a magnetic starter or contactor with appropriate power rating.
¶ Terminal Block Pinout
| Terminal | Function | Description |
|---|---|---|
| L | Phase 230V | AC mains power |
| N | Neutral 230V | Neutral wire |
| PE | Ground | Protective grounding |
| COM | Relay output (common) | Common relay contact |
| NO | Relay output (normally open) | Closes when relay activates |
| IN1+ | Discrete input 1 (isolated) | Positive terminal |
| IN1- | Discrete input 1 (isolated) | Negative terminal |
| IN2+ | Discrete input 2 (isolated) | Positive terminal |
| IN2- | Discrete input 2 (isolated) | Negative terminal |
| IN3 | Discrete input 3 | Input (closes to GND) |
| IN4 | Discrete input 4 | Input (closes to GND) |
| GND | Common wire | Ground for IN3, IN4 inputs |
| +5V | External device power | +5V DC output (up to 500 mA) |
¶ Additional Information
- Device Installation — installation instructions
- Battery Replacement — battery replacement
- Protocols and Commands — control commands and data formats
- ROSSMA Configurator — device configuration
- Troubleshooting — diagnostics and problem solving
¶ Related Pages
Software:
- ROSSMA Configurator — switch parameter configuration
- ROSSMA NETS Server — relay control, schedule and rule configuration
- Data Decoder — data packet analysis
Technical Documentation:
- Exchange Protocols — control command packet format
- LoRaWAN Technology — RU864 frequency plan, device classes
- Quick Start — first network connection
Other Devices:
- MODBUS — for industrial controllers
- PULSE — for pulse sensors
- ESD — for equipment security monitoring
- Device Catalog — all ROSSMA IIoT-AMS models