01MCU
Every phase of the busbar
The MCU-4 network analyser measures voltage, current, active, reactive and apparent power, cos φ and energy on each phase. Its active power accuracy is ±1 %.
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GridBit LV switchgear monitoring
GridBit brings the low-voltage board of a secondary substation online. A network analyser measures current, voltage, power and power quality on every phase, and a voltage detector watches the outgoing feeders, fuses and protections.
- Modbus modules and third-party sensors
- voltage inputs on one SMU-3 detector
- 8
- active power accuracy of MCU-4
- ±1 %
- harmonic orders the platform shows per phase
- 3 to 13
- Modbus devices one gateway can read
- 127
The problem
The first report often comes from a customer
Below the secondary substation the operator often learns about a fault from the customers. Without data from the low-voltage board, a DSO faces:
- 01More frequent and longer interruptions, worse SAIDI and SAIFI
How it works
From the DIN rail to the platform
The modules mount on the DIN rail of the board and share one Modbus RTU line with the gateway.
02SMU
A voltage check on every feeder
The SMU-3 detector reads AC voltage on eight inputs, isolated by 5000 V from its supply and the bus. A feeder whose fuse has blown or whose protection has tripped shows up as an input without voltage. The relay unit (RLU) switches lines on a schedule or on command.
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03GWU
One gateway for the board
The GWU-5 gateway reads up to 127 Modbus devices on one bus and sends their data with MQTT over 4G LTE, with 2G as fallback, or over Ethernet.
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04WDT
Keeps the electronics running
Surges and harmonics on the supply can make electronics hang. The WDT-1 watchdog relay follows the Modbus communication and, when it stops, operates its relay for a set time to restart the devices.
Open the module05Platform
The board in a browser
The platform shows the busbar and every outgoing circuit, and the power quality of the past week, phase by phase.
The platform
Every circuit of the board on one screen
The busbar and every circuit
Current and voltage per phase with the minimum, average and maximum for the period, then the same for each outgoing circuit.
Power quality over a week
Voltage deviation, rapid voltage changes, asymmetry and harmonics from the 3rd to the 13th with the total distortion, per phase.
Keep scrolling
Screens from the interface design, with sample data.
The platform
Every circuit of the board on one screen
The busbar and every circuit
Current and voltage per phase with the minimum, average and maximum for the period, then the same for each outgoing circuit.
Power quality over a week
Voltage deviation, rapid voltage changes, asymmetry and harmonics from the 3rd to the 13th with the total distortion, per phase.
Screens from the interface design, with sample data.
Functions
Set to your processes and systems
01
Automation
Processes, tasks, analyses and reports set to the needs of the client.
02
Integration
With systems of other vendors through standard protocols.
03
System configuration
Devices, users and thresholds managed from the interface.
Benefits
Faster response, safer work
Efficient operation
Faults and disruptions are detected at once, response is quick and downtime is short.
Safety
Hazards are identified early, so crews act in time and the risk of accidents drops.
In the field
The same modules run in street lighting cabinets
MCU-4 and SMU-3 already work in the field: they are part of GridBit street lighting management, the system that switches and measures street lighting cabinets across Bulgaria.
- street lighting cabinets
- 4 500+
- municipalities
- 70+
Hardware in this system
- Compact modules, combined as the substation needs
GatewayGWU-54G LTE gateway for Modbus devices, with Ethernet and MQTT4G LTE Cat 1Mobile network, 2G fallbackRS485 + EthernetModbus RTU and Modbus TCP
GatewayGWU-42G/4G gateway for Modbus RTU devices, two digital inputs4G LTE Cat 1Mobile network, 2G fallbackRS485Modbus RTU
MeterMCU-4Three-phase network analyser with Modbus RTU3P+N / 1P+NPole configurationU, I, P, cos φ, EMeasured parameters
InputsSMU-3Eight-channel AC voltage detector with Modbus RTU8Voltage detection inputs280 VACMaximum input voltage
WatchdogWDT-1Watchdog relay that restarts devices when Modbus communication stopsNormally openRelay contact250 VACMax. relay voltage
Sensors and units for the board
TS2Contact temperature sensor
TIROptical, contactless temperature sensor
RLURelay unit
Electrical infrastructure digitalization
Also on the same platform
GridBit Street Lighting
GridBit street lighting management
Control and monitor street lighting cabinets from one system, with schedules that follow sunrise and sunset, measurements per phase and alarms for every cabinet.
Learn more
GridBit Transformer Monitoring
GridBit MV/LV transformer monitoring
Temperature, load and alarms of the MV/LV transformer in a secondary substation, in real time. Sensors and a gateway go into the existing substation without changing the primary equipment.
Learn more
GridBit Asset Passportization
GridBit asset passportization
An asset register for DSOs, with an asset passport for every secondary substation that holds its identification, technical parameters and connected generation. It works on its own or together with monitoring.
Learn moreWhat does the system measure at the low-voltage board?
Current, voltage, power and power quality on every phase, and the state of the outgoing feeders, fuses and protections. On the DIN rail, the MCU-4 network analyser measures each phase and the SMU-3 voltage detector reads eight inputs.
Which power quality values does the platform show?
Voltage deviation, rapid voltage changes, asymmetry and harmonics from the 3rd to the 13th with the total distortion, per phase. The busbar view adds current and voltage per phase with the minimum, average and maximum for the period.
Does it work with systems and sensors from other vendors?
Yes. The platform integrates with systems of other vendors through standard protocols, and third-party Modbus sensors connect to the same line as the GridBit modules.
Are these the same modules as in street lighting cabinets?
Yes. MCU-4 and SMU-3 are also part of GridBit street lighting management, which runs in more than 4 500 street lighting cabinets in more than 70 municipalities in Bulgaria.
Ask for a proposal for your LV boards
Tell us how many boards you want to monitor and which values matter to you. We propose the modules and the gateway and send a quote.