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4NC5112-0BC20
Siemens 4NC5112-0BC20 available at EU Automation. Get in touch today for a quick price.
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What happens next?
1. Email confirmation
You will get an email confirming that we have received your enquiry.
2. Dedicated Account Manager
One of our team will be in touch to confirm your part(s) specification and condition.
3. Your quote
You will receive a comprehensive quote tailored to your specific needs.
The Siemens 4NC5112-0BC20 is a SENTRON window-type current transformer designed for accurate current measurement and monitoring in low-voltage electrical panels. Featuring a 50 A primary to 1 A secondary ratio (50:1) and a 2.5 VA rated burden, it provides dependable signal conversion for metering and control circuits. This Class 3 current transformer includes touch protection and is rated IP20 for use within enclosed installations. It mounts via screw fixing and connects on the secondary side using screw terminals. The compact housing measures 74.5 mm high, 48 mm wide and 80 mm deep, with capacity for a push-through conductor up to 17.5 mm diameter or a single busbar up to 12 mm wide, supporting straightforward integration in space-conscious switchboards. Suitable for ambient operating temperatures from -10 °C to +55 °C.
| Specification | Description |
|---|---|
| Manufacturer | Siemens |
| Part Number | 4NC5112-0BC20 |
| Alternative Part Number | 4NC51120BC20 |
| Product Type | Window-type current transformer (current transformer) |
| Product Range | SENTRON |
| Primary/Secondary Current Ratio | 50 A / 1 A (50:1) |
| Rated Primary Current | 50 A |
| Rated Secondary Current | 1 A |
| Accuracy Class | Class 3 |
| Rated Burden (Apparent Power) | 2.5 VA |
| Protection Rating | IP20 |
| Touch Protection | Yes |
| Secondary Connection Type | Screw-type terminals (screw connection) |
| Mounting Type | Screw fixing |
| Maximum Conductor Outer Diameter (Pass-Through) | 17.5 mm |
| Maximum Busbar Width (Pass-Through, single busbar) | 12 mm |
| Dimensions (W × H × D) | 48 mm × 74.5 mm × 80 mm |
| Ambient Operating Temperature | -10 °C to +55 °C |
| Reference Designation | T (per DIN EN 61346-2 / IEC 81346-2:2009) |
| Part Description (EN-GB) | Siemens SENTRON window-type current transformer designed for monitoring and metering applications, providing a 50 A to 1 A secondary output with Class 3 accuracy and 2.5 VA burden in a compact IP20 housing with screw terminal connection. |
What is this component used for?
It is a window-type current transformer used to scale a higher primary current down to a standard secondary current for metering and monitoring. For example, Siemens 4NC5112-0BC20 converts 50 A on the primary to 1 A on the secondary.
What is the current ratio?
The rated ratio is 50/1 A, meaning 50 A primary corresponds to 1 A secondary under rated conditions.
What are the rated primary and secondary currents?
The rated primary current is 50 A and the rated secondary current is 1 A.
What accuracy class is it?
It is Accuracy Class 3, which is typically suited to general-purpose measurement where high-precision metering is not required.
What does the 2.5 VA rating mean?
2.5 VA is the rated operating apparent power (burden) the transformer can supply at the secondary while remaining within its specified performance. The total connected burden (meter/input plus wiring) should be selected to stay within this rating.
What is the ingress protection rating?
The unit is rated IP20, meaning it is protected against finger-sized contact with live parts but is not protected against water ingress.
What type of electrical connection is used on the secondary side?
The secondary uses screw-type terminals for the output connections.
How is it mounted?
It is designed for screw fixing, allowing it to be securely fastened within a panel or enclosure.
What conductor or cable size can pass through the window?
The maximum outer diameter of the push-through conductor is 17.5 mm.
Can it be used with a busbar, and what is the maximum busbar width?
Yes. It supports a push-through busbar with a maximum width of 12 mm (for one busbar).
What are the overall dimensions?
Approximate dimensions are 74.5 mm (height) × 48 mm (width) × 80 mm (depth).
What ambient temperature range is it designed for?
The specified operating ambient temperature range is -10 °C to +55 °C.
Does it include touch protection?
Yes, it is specified with touch protection to reduce accidental contact with live parts when correctly installed in an appropriate enclosure.
What are common applications for a 50 A to 1 A current transformer?
Common uses include feeding 1 A input ammeters, energy meters, and monitoring devices in low-voltage distribution panels where a 50 A circuit needs to be measured indirectly.
- Converting a 50 A primary current to a standard 1 A secondary signal for panel meters and analogue ammeters
- Providing an isolated measurement signal for energy monitoring and sub-metering within low-voltage switchboards
- Feeding current inputs on power monitoring relays and multi-function electrical meters for load tracking and trend logging
- Supporting current measurement on distribution circuits to help validate feeder loading and balance phase currents
- Enabling current sensing on busbar or cable runs (within the stated pass-through limits) for retrofit instrumentation upgrades
- Supplying a scaled current signal for control and building management panels where 1 A CT inputs are required
- Assisting commissioning checks by allowing temporary metering connection via the secondary screw terminals
- Integrating into industrial control panels to provide current feedback for process monitoring and alarm thresholds
This content has been produced using multiple sources. EU Automation takes no responsibility for the accuracy of this information. Always consult the original equipment manufacturer for the most up to date instructions and information.
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Customer reviews
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