Description
Retrofitting commercial energy meters without cutting facility power.
MBS KBU 58 400/5 A is a German-engineered 400/5 A commercial split-core current transformer featuring Class 0.5 precision and a generous 50 × 80 mm busbar aperture, engineered for non-invasive retrofit current measurement on commercial switchboards without disconnecting power.
Non-Invasive Split-Core Retrofit
Clamps directly around live commercial copper busbars or heavy cable bundles, avoiding costly building power shutdowns.
400/5 A Ratio with Class 0.5 Precision
High-accuracy current step-down compliant with DIN EN 61869-2 for commercial energy meters and plant controllers.
Generous 50 × 80 mm Busbar Window
Easily accommodates solid copper busbars (up to 50 × 80 mm) or multiple large parallel cables.
German Industrial Build Quality (MBS AG)
Flame-retardant shatterproof housing with integrated color-coded screw-clamping brackets for vibration-proof mounting.
More product details
Shutting down main factory power to slide solid-core CTs over busbars costs thousands of euros in lost production. The KBU 58 splits open with a quick-release mechanism and latches securely around conductors.
- Split-core magnetic circuit snaps open and locks securely with positive mechanical engagement.
- 50 × 80 mm aperture fits standard 400 A commercial busbar profiles.
- High thermal short-circuit strength ($I_{th} = 60 \times I_n$) withstands extreme grid fault surges.
MBS KBU 58
Compare different models
Scroll sideways to compare every model.
Precision magnetic core with 0.72 kV industrial insulation.
Sizing multi-inverter commercial zero-export systems requires tight synchronization between the meter and the plant controller. The KBU 58 delivers clean 5 A secondary signals. Delivers certified Class 0.5 precision across dynamic commercial load profiles. Operating voltage up to 0.72 kV AC with 3 kV dielectric insulation test voltage (1 min). Color-coded screw terminals provide secure, vibration-proof secondary lead connections.
Fits standard 50 by 80 mm busbars
The 50 by 80 mm window envelopes flat copper rails or round insulated conductors up to 50 mm diameter.
Includes protective covers over M5 terminals
Nickel-plated M5 secondary screws maintain tight connection torque beneath clear protective shrouds.
Pairs with 5 A secondary energy meters
Directly supplies measurement signals to Chint DTSU666-CT and GoodWe GM330 meter inputs.
Technical data
Non-invasive split-core current sensing engineered for commercial switchboards, zero-export control, and peak shaving.
400/5 A German-engineered split-core current transformer with 50 × 80 mm busbar window.
Manufactured in Germany by MBS AG, the KBU 58 400/5 A enables non-invasive retrofit current measurement on commercial switchboards and large busbars. Its split-core snap-together design allows installation around existing 50 × 80 mm busbars without shutting down facility power or cutting heavy conductors.
- Ratio
- 400/5 A
- Precision
- Class 0.5
- Large Window
- 50 × 80 mm
- Power Shutdown
- Zero
Model & Type
- Brand
- MBS AG (Germany)
- Series
- KBU 58
- Model
- KBU 58 400/5A Kl.0,5
- Type
- Split-core (divisible) current transformer
- Core
- Divisible, fits over a live conductor or busbar
- Manufacturer SKU (series)
- 80038
- Origin
- Made in Germany
Electrical
- Primary current (A)
- 400
- Secondary current (A)
- 5
- Rated burden (VA)
- 1
- Accuracy class
- 0.5
- Nominal frequency (Hz)
- 50
- Max. operating voltage Um (kV)
- 0.72
- Insulation test voltage
- 3 kV, Ueff, 50 Hz, 1 min
- Thermal rated continuous current Icth
- 1.0 × IN
- Thermal rated short-time current Ith
- 60 × IN, 1 s
- Insulation class
- E
Mechanics
- Busbar window (mm)
- 50 × 80
- Round conductor (mm)
- 50
- Width (mm)
- 125
- Height (mm)
- 158
- Depth, overall (mm)
- 58
- Housing
- Unbreakable grey polycarbonate, flame retardant, ultrasonically welded
- Secondary terminals
- Nickel-plated, M5 × 10 mm, with integrated covers
Environment
- Operating temperature (°C)
- -5 ~ +40
- Storage temperature (°C)
- -25 ~ +40
Project fit
Where this model fits.
Scenarios that show which projects the MBS KBU 58 400/5 A split-core current transformer, Class 0.5 belongs in, what to verify before quoting, and when another model is the better pick.
Commercial Solar & Hybrid Inverter Metering (250 A to 400 A Service)
Commercial switchboards with main service ratings between 250 A and 400 A installing a Chint DTSU666-CT or GoodWe GM330 smart meter.
400/5 A ratio matches 250–400 A commercial service lines, installing without power interruption.
- BoundaryIf the main service entrance carries higher continuous current (500 A up to 1000 A+), step up to the higher ratio KBU 58 models. ---
- If the main service entrance carries higher continuous current (500 A up to 1000 A+), step up to the higher ratio KBU 58 models. ---
Documents
MBS KBU 58 Kl.0,5 datasheet (DE)Product questions
How do you ensure the split-core surfaces remain clean during installation?
Ensure magnetic core contact faces are free of dust before snapping the core closed. To maintain Class 0.5 accuracy, inspect the polished magnetic core mating surfaces before locking the top half. Any trapped dirt creates an air gap that degrades measurement precision.
System components
Required components
Chint DTSU666-CT smart meter
Item number: DLK-CHINT-DTSU666CT
DTSU666-CT needs 3 external current transformers with a 5 A secondary (not included in the meter): KBU 58 supplies exactly that interface.
Recommended components
GoodWe GM330 smart meter
Item number: DLK-GOODWE-GM330
GM330's CT input accepts an n:5A ratio, matching KBU 58's fixed 5 A secondary, for GoodWe-inverter export control/monitoring.
Optional components
GoodWe SEC1000S Smart Energy Controller
Item number: DLK-GOODWE-SEC1000S
SEC1000S bundles a GM3000 meter that also accepts an n:5A CT ratio, for multi-inverter parallel export control on GoodWe ET 5-10 kW sites.