Viridian CT Clamp for Clearline Inverter | VIR-CSI-CT | Export Power Limiting | DNO Compliance | G98 G99 Export Cap | Requires VIR-CSI-WIFI
Viridian CT Clamp for Clearline Inverter | VIR-CSI-CT | Export Power Limiting | DNO Compliance | G98 G99 Export Cap | Requires VIR-CSI-WIFI
Export Power Limiting DNO Compliance Grid Import/Export Meter Clearline Inverter Add-On Requires WiFi Module Viridian Solar
The Viridian CT Clamp for Clearline Inverter (VIR-CSI-CT) is the current transformer accessory that enables export power limiting on Clearline CSI inverters. Installed on the main grid supply cable in the consumer unit, it continuously measures the real-time power flow at the grid connection point and sends this data to the inverter, which dynamically adjusts its output to stay within a configured maximum export limit. This is essential where your DNO (Distribution Network Operator) connection approval specifies a maximum permitted export — for example, a G98 approval with a 3.68 kW export cap or a G99 approval with a specific export level. The CT clamp must be used alongside the VIR-CSI-WIFI WiFi module — both are required for the export limiting function to operate.
🔴 Important: The CT clamp must be installed on the grid supply cable (the live conductor between the electricity meter and the consumer unit) by a qualified electrician. Incorrect installation will result in incorrect export measurement and may cause the inverter to export more power than permitted. Both VIR-CSI-WIFI and VIR-CSI-CT are required for export limiting — neither works for this purpose without the other.
Key Features
- ✓Enables export power limiting on any Clearline CSI inverter — essential for DNO compliance where a maximum export cap is specified in your G98/G99 connection approval
- ✓Clamp-on installation — clips around the live (or neutral) grid supply conductor; no need to cut or splice the cable, minimising installation time
- ✓Connects to the inverter's RS485/CT communication port — dedicated port on all Clearline CSI models; no external data logger or meter required
- ✓Continuous real-time measurement — the inverter reads the CT output many times per second and adjusts its AC output power in real time to maintain the export set-point
- ✓Set export limit via WE Mate app — the installer configures the target export power level (in watts) under Advanced Settings → Power Limit; the inverter maintains this limit automatically
- ✓Zero-export operation — set the export limit to 0 W if your DNO or DNO approval requires no export at all (self-consumption only mode)
- ✓Works with all Clearline CSI models — compatible with all single-phase Clearline inverters from CSI1000S through CSI6000D
- ✓Must be used with VIR-CSI-WIFI or VIR-CSI-WIFI-S — the WiFi module provides the communication pathway between the CT clamp reading and the inverter's power control algorithm
When Do I Need a CT Clamp?
You need the CT clamp if your DNO connection approval (G98 or G99) includes any of the following: • A maximum permitted export power (e.g. 3.68 kW, 2 kW, or 0 kW) • A requirement for export limiting or zero-export operation • A condition that inverter output must be curtailed based on grid conditions If your connection approval has no export restriction, the CT clamp is not required. Check your DNO connection offer letter or consult your MCS installer for guidance.
Technical Specifications
| Specification | Value |
|---|---|
| Function | Current transformer for real-time grid import/export measurement |
| Installation Point | Grid supply cable between electricity meter and consumer unit |
| Installation Method | Clamp-on (split-core CT) — no cable cutting required |
| Connection to Inverter | RS485 / CT communication port (COM port 2 on all Clearline CSI models) |
| Required Companion | VIR-CSI-WIFI or VIR-CSI-WIFI-S WiFi module (must be fitted for export limiting to function) |
| Configuration | Via WE Mate app — Advanced Settings → Power Limit → Enable Power Limit → Set Export Power and CT Ratio |
| Compatible Inverters | All Viridian Clearline CSI range (CSI1000S–CSI6000D) |
| Installer Requirement | Qualified electrician — installation at consumer unit level involves live equipment |
| Manufacturer | Viridian Solar Ltd, Papworth, Cambridge |
Frequently Asked Questions
QDo I need a CT clamp if my DNO approval has no export restriction?
No. If your G98 or G99 connection approval places no restriction on export power, the CT clamp is not needed. Most simple domestic G98 systems under 3.68 kW can export freely. Check your DNO connection offer document to confirm whether an export limit applies.
QCan I use the CT clamp without the WiFi module?
No. Both the VIR-CSI-CT and VIR-CSI-WIFI are required together for export limiting. The CT clamp measures the current; the WiFi module communicates that measurement to the inverter's control system. Without the WiFi module, the inverter cannot read the CT clamp data.
QWhere exactly is the CT clamp installed?
The CT clamp is installed on the main grid supply conductor — typically the live (line) cable between your electricity meter and the main consumer unit. This allows it to measure the total power flowing to or from the grid (import and export). Installation at this point must be carried out by a qualified electrician.
QCan I set zero export (self-consumption only)?
Yes. Set the export limit to 0 W in the WE Mate app under Advanced Settings → Power Limit. The inverter will then continuously adjust its output to match household consumption, preventing any power from flowing back to the grid. Note that zero-export operation cannot be guaranteed under all dynamic conditions — response time means small transient exports may occasionally occur; this is normal and accepted by most DNOs.
QWhat happens if the CT clamp cable is disconnected after commissioning?
If the CT clamp communication is lost, the inverter will typically fall back to outputting at its unrestricted rated power. This may cause an export limit breach. Ensure the CT cable is routed and secured to avoid accidental disconnection, and check the WE Mate app for any communication fault alerts.
Viridian CT Clamp for Clearline Inverter | VIR-CSI-CT | Export Power Limiting | DNO Compliance | G98 G99 Export Cap | Requires VIR-CSI-WIFI
Export Power Limiting DNO Compliance Grid Import/Export Meter Clearline Inverter Add-On Requires WiFi Module Viridian Solar
The Viridian CT Clamp for Clearline Inverter (VIR-CSI-CT) is the current transformer accessory that enables export power limiting on Clearline CSI inverters. Installed on the main grid supply cable in the consumer unit, it continuously measures the real-time power flow at the grid connection point and sends this data to the inverter, which dynamically adjusts its output to stay within a configured maximum export limit. This is essential where your DNO (Distribution Network Operator) connection approval specifies a maximum permitted export — for example, a G98 approval with a 3.68 kW export cap or a G99 approval with a specific export level. The CT clamp must be used alongside the VIR-CSI-WIFI WiFi module — both are required for the export limiting function to operate.
🔴 Important: The CT clamp must be installed on the grid supply cable (the live conductor between the electricity meter and the consumer unit) by a qualified electrician. Incorrect installation will result in incorrect export measurement and may cause the inverter to export more power than permitted. Both VIR-CSI-WIFI and VIR-CSI-CT are required for export limiting — neither works for this purpose without the other.
Key Features
- ✓Enables export power limiting on any Clearline CSI inverter — essential for DNO compliance where a maximum export cap is specified in your G98/G99 connection approval
- ✓Clamp-on installation — clips around the live (or neutral) grid supply conductor; no need to cut or splice the cable, minimising installation time
- ✓Connects to the inverter's RS485/CT communication port — dedicated port on all Clearline CSI models; no external data logger or meter required
- ✓Continuous real-time measurement — the inverter reads the CT output many times per second and adjusts its AC output power in real time to maintain the export set-point
- ✓Set export limit via WE Mate app — the installer configures the target export power level (in watts) under Advanced Settings → Power Limit; the inverter maintains this limit automatically
- ✓Zero-export operation — set the export limit to 0 W if your DNO or DNO approval requires no export at all (self-consumption only mode)
- ✓Works with all Clearline CSI models — compatible with all single-phase Clearline inverters from CSI1000S through CSI6000D
- ✓Must be used with VIR-CSI-WIFI or VIR-CSI-WIFI-S — the WiFi module provides the communication pathway between the CT clamp reading and the inverter's power control algorithm
When Do I Need a CT Clamp?
You need the CT clamp if your DNO connection approval (G98 or G99) includes any of the following: • A maximum permitted export power (e.g. 3.68 kW, 2 kW, or 0 kW) • A requirement for export limiting or zero-export operation • A condition that inverter output must be curtailed based on grid conditions If your connection approval has no export restriction, the CT clamp is not required. Check your DNO connection offer letter or consult your MCS installer for guidance.
Technical Specifications
| Specification | Value |
|---|---|
| Function | Current transformer for real-time grid import/export measurement |
| Installation Point | Grid supply cable between electricity meter and consumer unit |
| Installation Method | Clamp-on (split-core CT) — no cable cutting required |
| Connection to Inverter | RS485 / CT communication port (COM port 2 on all Clearline CSI models) |
| Required Companion | VIR-CSI-WIFI or VIR-CSI-WIFI-S WiFi module (must be fitted for export limiting to function) |
| Configuration | Via WE Mate app — Advanced Settings → Power Limit → Enable Power Limit → Set Export Power and CT Ratio |
| Compatible Inverters | All Viridian Clearline CSI range (CSI1000S–CSI6000D) |
| Installer Requirement | Qualified electrician — installation at consumer unit level involves live equipment |
| Manufacturer | Viridian Solar Ltd, Papworth, Cambridge |
Frequently Asked Questions
QDo I need a CT clamp if my DNO approval has no export restriction?
No. If your G98 or G99 connection approval places no restriction on export power, the CT clamp is not needed. Most simple domestic G98 systems under 3.68 kW can export freely. Check your DNO connection offer document to confirm whether an export limit applies.
QCan I use the CT clamp without the WiFi module?
No. Both the VIR-CSI-CT and VIR-CSI-WIFI are required together for export limiting. The CT clamp measures the current; the WiFi module communicates that measurement to the inverter's control system. Without the WiFi module, the inverter cannot read the CT clamp data.
QWhere exactly is the CT clamp installed?
The CT clamp is installed on the main grid supply conductor — typically the live (line) cable between your electricity meter and the main consumer unit. This allows it to measure the total power flowing to or from the grid (import and export). Installation at this point must be carried out by a qualified electrician.
QCan I set zero export (self-consumption only)?
Yes. Set the export limit to 0 W in the WE Mate app under Advanced Settings → Power Limit. The inverter will then continuously adjust its output to match household consumption, preventing any power from flowing back to the grid. Note that zero-export operation cannot be guaranteed under all dynamic conditions — response time means small transient exports may occasionally occur; this is normal and accepted by most DNOs.
QWhat happens if the CT clamp cable is disconnected after commissioning?
If the CT clamp communication is lost, the inverter will typically fall back to outputting at its unrestricted rated power. This may cause an export limit breach. Ensure the CT cable is routed and secured to avoid accidental disconnection, and check the WE Mate app for any communication fault alerts.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
Export Power Limiting DNO Compliance Grid Import/Export Meter Clearline Inverter Add-On Requires WiFi Module Viridian Solar
The Viridian CT Clamp for Clearline Inverter (VIR-CSI-CT) is the current transformer accessory that enables export power limiting on Clearline CSI inverters. Installed on the main grid supply cable in the consumer unit, it continuously measures the real-time power flow at the grid connection point and sends this data to the inverter, which dynamically adjusts its output to stay within a configured maximum export limit. This is essential where your DNO (Distribution Network Operator) connection approval specifies a maximum permitted export — for example, a G98 approval with a 3.68 kW export cap or a G99 approval with a specific export level. The CT clamp must be used alongside the VIR-CSI-WIFI WiFi module — both are required for the export limiting function to operate.
🔴 Important: The CT clamp must be installed on the grid supply cable (the live conductor between the electricity meter and the consumer unit) by a qualified electrician. Incorrect installation will result in incorrect export measurement and may cause the inverter to export more power than permitted. Both VIR-CSI-WIFI and VIR-CSI-CT are required for export limiting — neither works for this purpose without the other.
Key Features
- ✓Enables export power limiting on any Clearline CSI inverter — essential for DNO compliance where a maximum export cap is specified in your G98/G99 connection approval
- ✓Clamp-on installation — clips around the live (or neutral) grid supply conductor; no need to cut or splice the cable, minimising installation time
- ✓Connects to the inverter's RS485/CT communication port — dedicated port on all Clearline CSI models; no external data logger or meter required
- ✓Continuous real-time measurement — the inverter reads the CT output many times per second and adjusts its AC output power in real time to maintain the export set-point
- ✓Set export limit via WE Mate app — the installer configures the target export power level (in watts) under Advanced Settings → Power Limit; the inverter maintains this limit automatically
- ✓Zero-export operation — set the export limit to 0 W if your DNO or DNO approval requires no export at all (self-consumption only mode)
- ✓Works with all Clearline CSI models — compatible with all single-phase Clearline inverters from CSI1000S through CSI6000D
- ✓Must be used with VIR-CSI-WIFI or VIR-CSI-WIFI-S — the WiFi module provides the communication pathway between the CT clamp reading and the inverter's power control algorithm
When Do I Need a CT Clamp?
You need the CT clamp if your DNO connection approval (G98 or G99) includes any of the following: • A maximum permitted export power (e.g. 3.68 kW, 2 kW, or 0 kW) • A requirement for export limiting or zero-export operation • A condition that inverter output must be curtailed based on grid conditions If your connection approval has no export restriction, the CT clamp is not required. Check your DNO connection offer letter or consult your MCS installer for guidance.
Technical Specifications
| Specification | Value |
|---|---|
| Function | Current transformer for real-time grid import/export measurement |
| Installation Point | Grid supply cable between electricity meter and consumer unit |
| Installation Method | Clamp-on (split-core CT) — no cable cutting required |
| Connection to Inverter | RS485 / CT communication port (COM port 2 on all Clearline CSI models) |
| Required Companion | VIR-CSI-WIFI or VIR-CSI-WIFI-S WiFi module (must be fitted for export limiting to function) |
| Configuration | Via WE Mate app — Advanced Settings → Power Limit → Enable Power Limit → Set Export Power and CT Ratio |
| Compatible Inverters | All Viridian Clearline CSI range (CSI1000S–CSI6000D) |
| Installer Requirement | Qualified electrician — installation at consumer unit level involves live equipment |
| Manufacturer | Viridian Solar Ltd, Papworth, Cambridge |
Frequently Asked Questions
QDo I need a CT clamp if my DNO approval has no export restriction?
No. If your G98 or G99 connection approval places no restriction on export power, the CT clamp is not needed. Most simple domestic G98 systems under 3.68 kW can export freely. Check your DNO connection offer document to confirm whether an export limit applies.
QCan I use the CT clamp without the WiFi module?
No. Both the VIR-CSI-CT and VIR-CSI-WIFI are required together for export limiting. The CT clamp measures the current; the WiFi module communicates that measurement to the inverter's control system. Without the WiFi module, the inverter cannot read the CT clamp data.
QWhere exactly is the CT clamp installed?
The CT clamp is installed on the main grid supply conductor — typically the live (line) cable between your electricity meter and the main consumer unit. This allows it to measure the total power flowing to or from the grid (import and export). Installation at this point must be carried out by a qualified electrician.
QCan I set zero export (self-consumption only)?
Yes. Set the export limit to 0 W in the WE Mate app under Advanced Settings → Power Limit. The inverter will then continuously adjust its output to match household consumption, preventing any power from flowing back to the grid. Note that zero-export operation cannot be guaranteed under all dynamic conditions — response time means small transient exports may occasionally occur; this is normal and accepted by most DNOs.
QWhat happens if the CT clamp cable is disconnected after commissioning?
If the CT clamp communication is lost, the inverter will typically fall back to outputting at its unrestricted rated power. This may cause an export limit breach. Ensure the CT cable is routed and secured to avoid accidental disconnection, and check the WE Mate app for any communication fault alerts.
