Custom Current Transformers
Current transformers turn a primary current into a safe, accurate secondary signal for metering, protection and current sensing. P&A International engineers, prototypes and delivers custom current transformers — measurement, protection and split-core types, ring and PCB-mount — built to your ratio, accuracy class, burden and frequency.
As an engineering-led contract manufacturer founded as an engineering consultancy, we assign one dedicated engineer to your project from design review to qualified samples in 10–15 working days, then scale into volume through our vetted partner-factory network, where every supplier is ISO 9000 certified or better.Request a quote ›
consultancy + manufacture
per project, end-to-end
qualified samples with test data
every supplier certified or better
one-off to high volume
Why choose PA current transformers
Accurate ratios
Tight turns-ratio and core selection for your accuracy class, burden and linearity.
Metering or protection
Measurement CTs for metering and protection CTs with the saturation behaviour your relay needs.
Ring or PCB
Toroidal ring, split-core and PCB-mount formats designed to your conductor and board.
Safe construction
Insulation and creepage to the relevant standards, with screens where required.
Engineering capability
- Magnetic design & simulation — ratio, accuracy class, burden, phase error, saturation
- Core material selection (nanocrystalline, permalloy, ferrite, silicon steel) for linearity and frequency
- Measurement, protection and split-core designs; ring and PCB-mount
- Burden and secondary winding designed to your meter / relay / ADC
- Insulation, creepage and screening to the relevant standards
- DFM review to hit target cost while preserving performance
- Qualified samples with full test data before any volume tooling
- One dedicated engineer owns the project end-to-end
At a glance
| Type | Current transformer — measurement / protection / split-core |
| Format | Ring (toroidal), split-core, PCB-mount |
| Ratio | Specified to your primary current & secondary |
| Accuracy | To your class & burden |
| Core | Nanocrystalline / permalloy / ferrite / Si-steel |
| Frequency | 50/60 Hz to high-frequency sensing |
| Prototype | 10–15 working days to qualified samples |
| Quality | Every supplier in our network is ISO 9000 certified or better |
Why engineers & buyers choose PA
For design engineers
A true design partner — one dedicated engineer, full simulation and DFM support, rapid samples, and current transformers designed for your accuracy class, burden, phase error and saturation. We design to your meter, relay or ADC — not just catalogue parts.
For purchasing
Low-risk scalability — predictable 10–15-day prototypes, flexible MOQ from one-off to production, target-cost DFM, a single point of contact, and a vetted ISO 9000+ partner network managed end-to-end by P&A. No hand-offs, no surprises.
3 easy steps to get started
Send us your spec
Send your drawing or spec sheet. One dedicated engineer reviews it and confirms the technical details with you.
Proposed design & quote
You receive a proposed design and indicative pricing — typically within 48 hours — to review and refine together.
Samples & production
Qualified samples with full test data in 10–15 working days; on approval we scale into volume through our partner network.
Applications
Energy metering & sub-metering · protection relays · power monitoring & PQ · inverters and drives · EV charging · current sensing in power electronics.
Explore related types: high-frequency & switch-mode magnetics, inductors & common-mode chokes and LAN & signal transformers.
Choosing the right current transformer
A few decisions shape every current-transformer design — sharing this detail lets us quote and prototype faster:
| Measurement vs protection | Measurement CTs prioritise accuracy at rated current; protection CTs must stay linear through fault currents. Tell us which. |
| Ratio & burden | Primary current, secondary (e.g. 5 A / 1 A / mA) and the burden of your meter, relay or ADC set the turns and core. |
| Accuracy class & phase error | Your required class and phase error set the core material and size. |
| Core material | Nanocrystalline, permalloy, ferrite or silicon steel are chosen for linearity, saturation and frequency. |
| Format | Ring (toroidal), split-core for retrofit, or PCB-mount, designed to your conductor and board. |
What to send us for a fast, accurate quote
The more of this you can share, the quicker we can return a proposed design and price:
- Primary current range and rated current
- Secondary output (5 A / 1 A / mA / voltage) and burden
- Accuracy class and phase-error requirement
- Format (ring / split-core / PCB) and conductor / window size
- Frequency and any saturation / fault-current requirement
- Target cost and annual volume or call-off pattern
- Any reference design, competitor part number or physical sample
Working from a competitor part or a sample is fine — our engineer will reverse-engineer it or design a drop-in equivalent to your specification.
📄 Download the current transformer RFQ checklist & selection quick reference (PDF)
Get a quote
Send your ratio, accuracy class, burden and format and one dedicated engineer will reply — typically within 48 hours — with a proposed design and indicative pricing.
One dedicated engineer reviews every enquiry and replies with a proposed design and indicative pricing. Your details are used only to respond to your enquiry. Prefer email? support@pa-international.com.au