Current Transformers (CTs) — 100A to 4000A
Current transformers (CTs) are the link between high-amperage conductors and low-voltage submetering hardware. By stepping primary current down to a safe 0–5A secondary, they let any compatible power meter — PAN-14, PAN-42, AcquiSuite, or third-party Modbus meters — measure circuits well beyond their direct-input rating. Sizing the right CT means matching the primary amperage to the conductor's full-load current with appropriate headroom, choosing split-core for retrofit installations or solid-core for new construction, and confirming the secondary output matches your meter's input (0–5A is the industry standard). The five amperages below — 100A, 600A, 1000A, 2000A, and 4000A — cover branch circuits through main service entrances and switchgear. Pick the section that matches your panel size to see specs and pricing.
100 amp CT
The 100A split-core CT is sized for branch circuits, individual tenant panels, and equipment-level submetering of motors, RTUs, and small AHUs. Its 1″ round window clamps over standard #4 AWG to 4/0 conductors without disconnecting service, making it the go-to choice for retrofit tenant-billing and ASHRAE 90.1 equipment monitoring. Pairs with PAN-14 wireless sensors or any 0–5A input meter. Class 1.0 accuracy is sufficient for energy management and operational submetering applications.
| Ratio | 100:5 |
| Accuracy | Class 1.0 |
| Burden | 1.5 VA |
| Secondary | 0–5A |
| Window | 1.0" round |
| Frequency | 50/60 Hz |
| Form | Split-core |
| SKU | EES-CT-100 |
600 amp CT
The 600A split-core CT targets medium distribution panels, subfeeders, and large rooftop units in commercial buildings. The 2.5″ window accommodates 350 MCM through 500 MCM conductors common on 400A–600A feeder runs. Typical applications include grocery refrigeration racks, multi-tenant retail metering, and central plant chiller submetering. Class 1.0 accuracy supports billing-grade tenant allocation and ASHRAE 90.1 reporting when paired with a PAN-42 or any 0–5A input revenue meter.
| Ratio | 600:5 |
| Accuracy | Class 1.0 |
| Burden | 2.5 VA |
| Secondary | 0–5A |
| Window | 2.5" round |
| Frequency | 50/60 Hz |
| Form | Split-core |
| SKU | EES-CT-600 |
1000 amp CT
The 1000A split-core CT is the workhorse for large feeders and 800A–1200A main service entrances in mid-rise commercial and light industrial buildings. The 3″ window fits up to 750 MCM or paralleled 500 MCM conductors. Class 0.5 accuracy makes this CT suitable for revenue-grade submetering, utility-reporting applications, and high-precision energy-management baselines. Common deployments include central plants, hospital wings, university dorms, and large manufacturing line metering.
| Ratio | 1000:5 |
| Accuracy | Class 0.5 |
| Burden | 5 VA |
| Secondary | 0–5A |
| Window | 3.0" round |
| Frequency | 50/60 Hz |
| Form | Split-core |
| SKU | EES-CT-1000 |
2000 amp CT
The 2000A CT is sized for main service entrances in large commercial buildings, hospitals, data centers, and industrial facilities. The 4″ rectangular window clamps over busbar or large paralleled conductors typical of 1600A–2000A switchgear feeds. Class 0.5 accuracy and 7.5 VA burden support long secondary runs to centralized metering panels. Pairs with PAN-42 or any revenue-grade 0–5A input meter for billing-quality whole-building or department-level submetering.
| Ratio | 2000:5 |
| Accuracy | Class 0.5 |
| Burden | 7.5 VA |
| Secondary | 0–5A |
| Window | 4.0" rectangular |
| Frequency | 50/60 Hz |
| Form | Split-core |
| SKU | EES-CT-2000 |
4000 amp CT
The 4000A solid-core CT is built for the largest service entrances and utility-grade metering applications — campus main switchgear, large industrial plants, data center utility tie-ins, and submetering at the medium-voltage transformer secondary. The 6″ rectangular window fits busbar terminations on 3000A–4000A gear. Class 0.5 accuracy with a 10 VA burden rating supports long copper-secondary runs and high-impedance meter inputs. Specify during new construction or planned shutdowns; the solid-core form requires bus disconnection during installation.
| Ratio | 4000:5 |
| Accuracy | Class 0.5 |
| Burden | 10 VA |
| Secondary | 0–5A |
| Window | 6.0" rectangular |
| Frequency | 50/60 Hz |
| Form | Solid-core |
| SKU | EES-CT-4000 |
How to choose a CT amperage
Compatible & Related Products
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