EI-120 Automatic Lamination Stacking Machine for 1000-2000VA Industrial Power Transformer Cores | ±0.1 mm, 250 Stacks/Min, PLC, CE

The EI-120 inserts E and I silicon steel laminations into transformer coil bobbins under PLC control, with servo-driven sheet feed, ±0.02 mm positioning accuracy and ±0.1 mm stacking accuracy at up to 250 stacks per minute. It is the frame we recommend for the 1000-2000 VA band of industrial power and control transformers, where one platform has to cover several core sizes without losing the stack on changeover.

Most machine listings tell you what a machine can do. Fewer tell you when not to buy it. For a capital item that will sit on your floor for a decade, the second question matters more, so here is an honest selection guide for the EI-120 — including the two cases where we will point you at a different frame.

If your core sits on a boundary between two frames, send the stack drawing. The decision usually turns on the bobbin window and stack height, not on the VA figure alone.

• A repeatable process, not a fast operator — ±0.1 mm stack accuracy and ±0.02 mm positioning hold the effective air gap where the design put it, shift after shift and after a tooling change.
• One platform across your range — a stored recipe per core size means changeover is a recall, not a re-setup. A mixed catalogue stops being a scheduling problem.
• Traceable output — the PLC counts every lamination and records the cycle, so a finished stack can be tied to the run that produced it.
• Protection for thin steel — gentle servo feed and controlled insertion preserve the insulation coating on 0.3 mm sheet, which is where eddy-current loss is decided.
• Jam detection as standard — the cycle stops on a misfeed before laminations are crushed or tooling is marked.
• CE-certified build — high-strength structural steel frame, dual grounding (220 V + 24 V), AC220V overload and DC24V short-circuit protection, emergency stop and safety guarding.

Understanding the sequence is the fastest way to judge whether a stacker will fit your line. On the EI-120 the cycle runs in six controlled stages:

1. Servo sheet feed — laminations are released from the magazine at a controlled rate; the servomotor sets feed position rather than a fixed mechanical stop, which is what makes a stored recipe possible at all.
2. Presence confirmation — the sensor confirms the lamination before the stroke is allowed; a missing sheet is a fault, not a silent skip.
3. E-lamination placement — the E lamination is positioned into the bobbin window to the stored depth, at ±0.02 mm repeatability.
4. I-lamination insertion — the I lamination is driven home against the E stack; insert depth follows the recipe, not the operator's feel.
5. Stack count verification — each completed stack is counted and compared with the recipe; a short or long stack raises a fault instead of passing quietly into the varnish line.
6. Fault logging and recipe hold — misfeed, jam and short-stack events stop the cycle and are written to the controller with a timestamp; core size, count and depth stay loaded until deliberately changed.

Why the 36 mm window is the number to check first

On a 1000-2000 VA EI core, the bobbin window is the constraint that decides whether a mid-size frame can physically complete the stack. If your bobbin flange or wall thickness sits outside the approximately 36 mm window, no amount of parameter tuning will fix it — you need the next frame up. This is the single question that most often turns a "yes" into a "not this model", and it is worth resolving before price is discussed.

When an industrial power transformer buyer or a control panel builder qualifies a new source, the questions are rarely about price first. They ask how the core is assembled, how you know it is assembled correctly, and what happens when it is not. Those three answers decide whether a trial order becomes a framework agreement.

How is the core assembled? Laminations are fed, positioned and inserted by machine to ±0.1 mm stacking accuracy with ±0.02 mm positioning repeatability, from a stored recipe. The process does not depend on which operator is on shift.

How do you know it is correct? The PLC counts every lamination and records the cycle result. Stack count, insert depth and timing are held in a stored recipe per core size, so the specification on the drawing is the specification that was run.

What happens when it is not? Photoelectric and position sensing stop the cycle before laminations are crushed, the fault is written to the controller with a timestamp, and the affected piece is traceable to its batch.

Below a few hundred VA, a loose stack shows up as a buzz you can hear. At 1000-2000 VA it shows up as heat. The effective air gap and the clamping pressure inside the core set the magnetising current, and a stack that is tight at the top and loose at the bottom changes the loss pattern along the limb. In a continuously rated industrial power transformer that becomes a hot spot inside a sealed unit — the one failure mode with no service access.

The second cost is the insulation coating. On 0.3 mm sheet the interlamination coating is the only thing standing between you and shorted laminations at the burr edges. A feed that grabs or a stroke that overshoots marks that coating, and the loss shows up in the no-load test weeks later, after the unit is wound and varnished. A controlled servo feed is a loss-control measure, not a speed feature.

Large industrial power transformers, three-phase control units built around single-phase EI cores, industrial power supplies, welding power sources and heavy-duty isolation transformers in the 1000-2000 VA band. CRGO and CRNGO grades are both supported at 0.3 mm, 0.35 mm and 0.5 mm thickness, with cardboard or plastic bobbins. The machine runs standalone or inline with winding and varnishing.

The full series runs from EI-19 to EI-300. [Confirm current frame list and window dimensions for the catalogue page — this table is the highest-value internal-link target on the site.]

• EI-120 stacking machine, assembled and cycle-tested before packing
• Mitsubishi PLC controller with touch-screen HMI and the core recipes agreed at order
• Servo feed and photoelectric misfeed sensing set, installed and calibrated
• Operation and maintenance manual, English [confirm additional languages]
• CE declaration of conformity and electrical schematic
• Recommended spare-parts list with part numbers for local sourcing
• Export packing: plywood case, braced for LCL or FCL [confirm packing spec]

• Lead time: 1-15 working days for standard configurations.
• Minimum order quantity: 1 unit — one machine is enough to run a trial programme.
• Payment terms: T/T. [Confirm deposit / balance ratio.]
• Indicative price: US$3,000 per unit. Final quotation follows drawing review; voltage, bobbin type and recipe count are the variables that move it.
• Warranty: 12 months.
• After-sales: professional technical support from the manufacturing team. [Confirm response time and whether spare parts are held for 5 or 10 years.]
• Installation: bench-top unit, 220 V single-phase supply (380 V on request) and 0.4-0.65 MPa dry air. [Confirm whether remote or on-site commissioning support is included.]

Automatic EI lamination stacking machine for 1000-2000 VA transformer cores. ±0.1 mm stacking accuracy, ±0.02 mm positioning, servo-driven feed, up to 250 stacks per minute, Mitsubishi PLC with a stored recipe per core size, 0.3/0.35/0.5 mm CRGO and CRNGO laminations, cardboard or plastic bobbins, approx. 36 mm bobbin window, AC 200-250 V, 70 kg, 12-month warranty, CE marked, MOQ 1 unit, 1-15 working days lead time.