Schneider Electric 33570 ComPact NS1600N 1600 A 4P Breaker

33570: 1600 A ComPact NS1600N 4-pole breaker, MicroLogic 5.0

The 33570 is a fixed-mounting Schneider Electric ComPact NS molded-case circuit breaker rated 1600 A at 50 °C, listed in the datasheet as: circuit breaker Compact NS1600N – Micrologic 5.0 – 1600 A – 4 poles 4t. Seven Star LLC supplies it in Oman and the GCC as an independent supplier based in Muscat.

The device short name in the datasheet is Compact NS1600N. In this naming the digits give the frame current class, and the letter N is the breaking-capacity level: the datasheet’s performance level reads N 50 kA at 415 V AC. The trip unit is MicroLogic 5.0, an LSI electronic unit, and the device has 4 protected poles (4D), with the neutral pole on the left.

Please note that the datasheet carries a discontinued notice dated 30 Sep 2024. Seven Star LLC can still quote the 33570 where stock or alternatives exist, but availability should be confirmed before it is specified for a new project; for a like-for-like replacement we need the full nameplate of the breaker being replaced.

Technical specifications of the 33570

MicroLogic 5.0 settings on the 33570

The MicroLogic 5.0 is an LSI unit: long-time overload (L), short-time short-circuit (S) and instantaneous short-circuit (I) protection. The added short-time stage is what lets this breaker ride through a brief fault for a chosen time while a downstream breaker clears it, which is the basis of time-delayed selectivity on a distribution board.

Long-time pick-up Ir runs from 0.4 to 1 x In in 9 settings, so on this 33570 (In = 1600 A) from 640 A to 1600 A. The long-time delay tr is 12.5 to 600 s at 1.5 x Ir, 0.5 to 24 s at 6 x Ir and 0.7 to 16.6 s at 7.2 x Ir, with a 20 minute thermal memory.

The short-time pick-up Isd is adjustable from 1.5 to 10 x Ir in 9 settings, up to 16,000 A at Ir = 1600 A (calculated). The short-time delay tsd is 0 to 0.4 s with I²t off and 0.1 to 0.4 s with I²t on. The instantaneous pick-up Ii is 2 to 15 x In, or Off; for this rating that is 3,200 A to 24,000 A when it is in use.

Breaking capacity of the 33570 by voltage

The datasheet lists the following ratings, conforming to IEC 60947-2. Icu is the ultimate breaking capacity; Ics is the rated service breaking capacity.

For the 1600 A frame the service breaking capacity Ics is lower than Icu: 37 kA at 380/415 V against 50 kA Icu, so the Ics/Icu ratio is not 100 %.

Icw is 19.2 kA for 1 s; utilisation category B.

Current rating, poles and heat in the panel for the 33570

At 415 V a three-phase load of 1600 A corresponds to roughly 1,150 kVA (calculated as √3 x 415 V x 1600 A; not a datasheet value). The datasheet gives the rated current as 1600 A at 50 °C, with the device operating in ambient temperatures up to 70 °C, so in a hot switchroom the loading of the 33570 should be checked against the manufacturer’s derating information rather than assumed to be 1600 A.

The 33570 is the four-pole version: 280 mm wide and 18 kg, against 210 mm and 14 kg for the three-pole reference of the same rating. The neutral is on the left. The datasheet lists neutral protection settings of no protection (3D), 0.5 x Ir (3D + N/2) and 1 x Ir (4D), so the neutral can be left unprotected, set to half the phase pick-up or set equal to it. Four-pole breakers are chosen for TN-S systems with significant third-harmonic or unbalanced single-phase load, and where the neutral must be switched by the same device.

The datasheet states power losses of 74 W for this device. That heat stays inside the enclosure, so when several breakers sit in one cubicle their dissipation is added to the busbar and cable losses when the cooling or ventilation is sized.

Related ComPact NS references

Seven Star LLC also handles other ComPact NS references. Check poles, trip unit and breaking-capacity level before substituting any of them for the 33570.

33568 is NS1600N with 3 poles instead of 4.

Accessories such as release coils, rotary handles and motor mechanisms are separate part numbers; send them with the breaker reference for a complete quotation.

Installing and maintaining the 33570

Before energising, check that the 33570 is mounted on its backplate, that busbars or cable lugs match the 70 mm connection pitch and that the contact surfaces are clean. Then set the trip unit: Ir first, then tr, then the short-circuit thresholds. Record the settings on the single-line diagram. Because the unit is LSI, the Isd and tsd settings must be coordinated with the downstream breakers, and if Ii is set to Off the short-circuit stage relies on Isd alone.

The trip unit has 4 red LEDs for fault indication and 1 yellow LED for overload, a first diagnosis after a trip. Electrical durability is 1000 cycles at 690 V In; 2000 at 690 V In/2; 2000 at 440 V In; 5000 at 440 V In/2; use it when planning inspection intervals.

With IP40 and IK07 protection and pollution degree 3, the 33570 belongs inside an enclosed switchboard; the stated humidity limit is 0 to 95 %.

Where the 33570 is used in Oman and the GCC

A 1600 A rating is used on the larger incomers and bus-section positions: the LV side of a 1000 kVA class transformer, central chiller plants, compressor houses and the main board of an industrial building. In the Gulf the real constraints are ambient temperature in electrical rooms, dust from desert wind and humidity near the coast, which is why enclosure ventilation and the breaker’s operating ambient of up to 70 °C deserve a check. The MicroLogic 5.0 with its short-time stage gives a selective-capable device for boards with several tiers of protection.

Information to send with an RFQ for the 33570

To quote quickly and correctly, please send:

• Reference 33570 and quantity; also state whether a replacement for an existing device is intended, since the datasheet shows it as discontinued.
• Poles needed (4) and, for a four-pole device, the neutral protection setting expected.
• System voltage, available fault level at the board and the intended Icu level (N).
• Trip unit required (MicroLogic 5.0) and whether the settings will be supplied by the protection study.
• Control type (toggle or rotary handle) and any accessories required.
• Delivery location in Oman or the GCC, required documents and target date.

Documents and quotation

The official English datasheet for the 33570 is attached on this page. It lists the electrical data, trip-unit settings, dimensions and environmental information used above, and carries the discontinued notice mentioned earlier.

To request a quotation, send the part number 33570, the quantity and the delivery location. Seven Star LLC is an independent supplier in Muscat and quotes according to current availability.