Blue Sea 150A/50mA AC Current Sensing Coil for AC Ammeters
Blue Sea 150A/50mA AC Current Sensing Coil for AC Ammeters
Non-Invasive Toroidal Current Transformer with Wire Leads for Ammeters

DESCRIPTION
Non-Invasive AC Current Monitoring for Ammeters and Power Systems
The BS-8256B AC Current-Sensing Coil is a precision current transformer designed to provide safe, accurate, and non-invasive monitoring for AC electrical systems. Engineered specifically for integration with compatible AC ammeters, this toroidal sensing coil measures alternating current up to 150A and steps it down via a precise 150A/50mA transformation ratio. By isolating the measurement instrument from the primary high-current conductor, it simplifies installation and enhances system safety across marine, off-grid solar, caravan, and industrial power distribution boards.
Safe and Reliable Current Transformer Technology
Monitoring high-amperage AC circuits directly can present significant safety risks and installation challenges. Utilising a toroidal core design, this current-sensing coil allows the primary AC conductor to pass straight through the centre aperture without requiring you to cut or splice into heavy-gauge power cables. As alternating current flows through the main conductor, the coil induces a proportional 50mA secondary signal. This low-level output is then safely transmitted via the attached insulated black wire leads directly to your AC ammeter or energy monitoring display.
Key Features and Benefits
- 150A/50mA Transformation Ratio: Accurately scales down high primary currents up to 150A into a manageable 50mA signal for precise ammeter readings.
- Non-Invasive Toroidal Core: Allows the main AC conductor to pass through the sensing ring, eliminating the need to interrupt high-current connections during installation.
- Pre-Attached Wire Leads: Supplied with insulated black wire leads for straightforward routing and connection to your compatible AC measurement device.
- Enhanced Electrical Isolation: Separates high-energy AC circuits from delicate dashboard instruments and user-facing control panels, reducing the risk of equipment damage.
- Clear Identification: Features a permanent, high-contrast label displaying the transformation ratio for easy verification during system servicing or troubleshooting.
Why Choose a Dedicated AC Sensing Coil?
When building or upgrading an AC electrical switchboard, relying on uncalibrated or poorly insulated measurement components can lead to inaccurate load readings and potential thermal hazards. A dedicated current transformer like the BS-8256B ensures consistent linearity across its 150A operating range. This allows system operators to accurately track heavy AC loads, such as air conditioning units, water heaters, and high-output inverter chargers, preventing accidental circuit overloads and nuisance breaker trips.
Whether you are fitting out a commercial marine vessel, assembling a custom off-grid cabin control panel, or replacing a damaged sensor on an existing AC ammeter setup, this compact circular coil fits neatly inside tight electrical enclosures and distribution boxes.
Upgrade Your AC Power Monitoring
Ensure accurate load management and seamless integration with your compatible AC ammeter. Add the BS-8256B 150A/50mA AC Current-Sensing Coil to your system today for reliable, non-invasive electrical monitoring.
SKU: BS-8256B
SPECIFICATIONS
Specifications
| Main product or range | AC ammeters |
|---|---|
| Base product type | AC current-sensing coil |
| Accessory Function | current-transformer |
| Transformation Ratio | 150A/50mA |
| Rated Current | 150 |
| SKU: | BS-8256B |
| Package weight: | 0.3 kg |
| Package length: | 0.15 m |
| Package width: | 0.12 m |
| Package height: | 0.08 m |
WARRANTY
Blue Sea Warranty Policy
Blue Sea Systems products sold by us are supplied with a warranty against defects for the warranty period shown below, subject to the product type, application and the terms of this warranty policy.
The express warranty provided by us is limited to a maximum of 5 years from the original date of purchase, unless otherwise required under Australian Consumer Law.
Blue Sea Systems may offer longer manufacturer support on some products at their discretion
Warranty Lengths by Product Range
| Blue Sea Product Range | Warranty Length | Application / Notes |
|---|---|---|
| Most Blue Sea Systems Products | 5 years | Applies to most Blue Sea Systems products found to be defective in materials or manufacture. |
| P12 Battery Chargers | 5 years | Warranty period starts from the original date of purchase. |
| P12 Remote Displays | 5 years | Warranty period starts from the original date of purchase. |
| Digital Meters | 3 years | Warranty period starts from the original date of purchase. |
| Vessel System Monitors | 3 years | Warranty period starts from the original date of purchase. |
Warranty Assessment and Remedy
If a Blue Sea Systems product is found to be defective in materials or manufacture within the applicable warranty period, we will, at our discretion, arrange a repair, replacement, store credit or refund, depending on the nature of the fault and the requirements of Australian Consumer Law.
Products may need to be returned for assessment before a warranty claim can be approved. Where required, the product must be returned with dated proof of purchase and a clear description of the fault.
Labour costs for removing, replacing, reinstalling or diagnosing a product are not covered by this express warranty unless otherwise required under Australian Consumer Law.
Making a Warranty Claim
To make a warranty claim, please contact us with your dated proof of purchase, product details and a description of the fault.
The product may need to be returned for inspection before the claim can be assessed. If the product is confirmed to be faulty and covered by this warranty, we will advise the available remedy.
What This Warranty Does Not Cover
This warranty does not cover faults or damage caused by incorrect installation, incorrect application, misuse, abuse, neglect, unauthorised modification, accidental damage, normal wear and tear, environmental damage, or failure to use the product in accordance with the manufacturer's instructions.
- Incorrect installation or wiring
- Incorrect product selection or application
- Misuse, abuse or neglect
- Physical or accidental damage
- Water ingress or environmental damage outside the product's intended use
- Unauthorised modification or repair
- Normal wear and tear
- Labour costs for removal, replacement, reinstallation or diagnosis
- Freight, travel or call-out costs unless otherwise required by law
- Products not returned for assessment when reasonably required
Manufacturer Support
Blue Sea Systems may provide additional manufacturer support on some products beyond the warranty period listed above. Where available, we may assist customers in contacting the manufacturer, but any manufacturer support beyond the express warranty period is subject to the manufacturer's own terms and continued availability.
Australian Consumer Law
This warranty is in addition to other rights and remedies available at law. Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.







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