What the JS4000 Is and Where It Fits

The JS4000 is a forced twin-shaft concrete mixer with a 4.0 m³ discharge capacity per batch. It is the largest standard twin-shaft mixer in this range, and in our product line it is the mixer fitted to the HZS240 concrete batching plant. If you are building or rebuilding a high-output plant and the mixer is the constraint, this is the unit that sets the ceiling.

Two horizontal shafts run through the mixing drum with arms arranged in a spiral. The shafts turn in opposite directions, so material is pushed up the drum walls and folded back into the middle, where the fastest-moving zone is. In practice that means a 4 m³ batch is homogeneous in roughly one minute of mixing, and the same geometry scours the drum as it works — which is why twin-shaft mixers handle low-slump, high-fines and fibre-reinforced mixes that a single-shaft drum mixer struggles to blend evenly.

The numbers that matter for matching it to a plant: 4.0 m³ discharge, 140–170 m³/h practical output, 60-second cycle, 90 kW installed, and a maximum aggregate size of 60/80 mm (pebble/stone). The 140–170 m³/h figure is the mixer's own practical throughput with realistic charging; inside an HZS240 the plant is rated at 240 m³/h theoretical, which assumes a one-minute batch cycle sustained by adequate aggregate feed and truck exchange.

Power Requirement and Starting Load

The JS4000 draws 90 kW in total from two 45 kW motors, one on each shaft. The two motors drive through a reduction gearbox that keeps the shafts synchronised; they are not independent drives, and replacing one motor without matching the other is a common and expensive mistake.

The number buyers underestimate is not the running load but the starting load. Two 45 kW motors starting together pull a multiple of their rated current, and how that is handled depends on what you specify:

• Star-delta starting is the usual economic choice and is adequate on a supply with reasonable capacity.
• Soft starter or variable frequency drive reduces the starting surge and is worth the extra cost where the supply is weak, the transformer is shared, or the local utility limits starting current.
• Generator operation has to be sized on starting current, not on the 90 kW running figure. A generator matched only to the rated load will stall or trip when both motors come on together.

Tell us your supply voltage, frequency and starting arrangement with the enquiry. The mixer is built to the voltage you specify, and retrofitting a different control arrangement on site costs far more than specifying it correctly at the factory.

Twin-Shaft vs Other Mixer Types

At 4 m³ the realistic alternatives are a larger single-shaft drum mixer or a planetary mixer. The comparison below is the one we use with buyers, and it explains why twin-shaft dominates this size class in batching plants.

	Twin-shaft (JS4000)	Single-shaft drum	Planetary
Mixing action	Two counter-rotating shafts; material folded through a high-shear central zone	Rotating drum with fixed blades; gentler, slower action	Mixing arms orbiting the drum; very high shear
Cycle time at this size	About 60 seconds for a homogeneous 4 m³ batch	Longer for the same homogeneity, especially on low-slump mixes	Short, but the batch size is usually smaller
Fibre and low-slump mixes	Handles them; the folding action disperses fibre without balling	Prone to balling and dead zones	Handles them well
Wear pattern	Arms and liners wear predictably and are replaced individually	Liner wear is uneven	High wear on arms and pan, higher maintenance cost
Where it belongs	Batching plants from HZS90 upward — the default choice	Small plants and precast where output is not critical	Precast and special mixes, not bulk plant output

Wear Parts: What Wears and How Often

A mixer this size is bought for a decade, so the wear list matters more than the purchase price. Four items account for almost all maintenance on a JS4000:

• Mixing blades and arms. The fastest-wearing parts, and the ones that control mix quality. As blade edges wear, the clearance between arm and liner opens and mixing efficiency drops before anything actually breaks — which is why the clearance is checked on a schedule rather than on failure.
• Drum and end liners. Bolt-on plates; replaced individually as they thin. Keeping a plant running on worn liners costs more in blade wear than the liners cost.
• Shaft end seals. The usual source of a leak. Cement slurry reaching the bearing is what turns a cheap seal into a gearbox repair, so seals are replaced on condition rather than on failure.
• Discharge gate and its actuator. Hydraulic or pneumatic depending on specification; the gate seals are a wear item and a leaking gate shows up as a slow, dirty discharge.

We supply the wear-part set with the mixer and keep the list on file against your serial number, so reordering later does not depend on someone remembering the specification. Ask for the recommended inspection interval with the quotation — it depends on your mix design and how many batches you run per shift, not only on the model.

What to Confirm Before Ordering

Five items decide whether the mixer drops into your plant or needs modification afterwards:

• Supply voltage and frequency — built to your specification, not adapted on site.
• Discharge height — 3.2 m is standard; confirm it suits your skip, hoist or conveyor arrangement.
• Feeding method — skip hoist or belt conveyor changes the frame and the interface points.
• Control interface — standalone control panel, or integration with an existing plant PLC.
• Aggregate grading — the standard maximum is 60/80 mm; tell us if you run larger stone.

Send us the plant model you are fitting it to, or the drawings if it is a retrofit, and we will confirm the interface rather than leave it to the site team.

JS4000 Concrete Mixer FAQ

What is the power of a JS4000 concrete mixer?

90 kW in total, from two 45 kW motors — one on each mixing shaft. The two motors drive through a reduction gearbox that keeps the shafts synchronised, so the running load is 90 kW while the starting load is higher and depends on whether you specify star-delta, a soft starter or a VFD.

What is the output of a JS4000 mixer?

A 4.0 m³ discharge per batch on a 60-second cycle, which is 240 m³/h theoretical. Practical throughput is 140-170 m³/h depending on aggregate charging, mix design and how quickly trucks are exchanged. Inside an HZS240 plant the plant is rated at 240 m³/h theoretical on the basis of a one-minute cycle.

Which batching plant uses the JS4000?

The HZS240 in our range. The smaller models step down: HZS60 uses the JS1000, HZS90 the JS1500, HZS120 the JS2000 and HZS180 the JS3000. If you are uprating an existing plant, tell us the model and we will confirm whether the JS4000 fits the frame and the feed arrangement.

Can the JS4000 run on a generator?

Yes, but the generator must be sized on starting current rather than on the 90 kW running load. Two 45 kW motors starting together draw several times their rated current, and a generator matched only to the running figure will stall or trip. Tell us the generator rating and we will confirm the starting arrangement.

How long does a JS4000 last?

The frame and gearbox are designed for many years of production; the wear parts set the maintenance cycle. Mixing blades and arms wear fastest, then drum liners and shaft end seals. We supply a wear-part set with the mixer and hold the list against your serial number so reordering does not depend on remembering the specification.

Do you supply the JS4000 as a standalone mixer or only with a plant?

Both. It is supplied as a standalone mixer for retrofit or replacement, or as part of an HZS240 plant. For a retrofit, send us the existing plant drawings or the model and we will confirm the discharge height, feeding method and control interface before the order.