KYN28A-12 Metal-Clad Mid-Mounted Switchgear

Start from the voltage class. 40.5 kV goes to KYN61-40.5 and 24 kV to KYN□-24; only at 12 kV and below is the choice between KYN28A-12, KYN550-12 and YF-KYN450-12. Among those three, KYN28A-12 has the widest fault range at 16-50 kA and rated current to 3150 A, which makes it the broadest fit. KYN550-12 takes a main busbar to 4000 A and offers cubicle widths from 550 to 1000 mm, suiting high current where width is also constrained. YF-KYN450-12 is the compact type at 475-550 mm wide and 1100 mm deep, for projects short of switchroom area. The series page carries the full five-model comparison.

It is set with it. The voltage class follows the system nominal voltage and the insulation level follows the class: 3.6 kV pairs with 24 kV power-frequency withstand and 40 kV lightning impulse; 7.2 kV with 32 kV and 60 kV; 12 kV with 42 kV and 75 kV. These are pairs, and a lower class insulation level cannot be used at a higher class voltage. Give us the system nominal and highest operating voltage with the enquiry and the insulation level follows from them.

By the system fault capacity, not by the load current — this is the point most often reversed. Send the fault capacity at the installation point, or the short-circuit current calculation, and the rating is taken as the first of the six steps — 16, 20, 25, 31.5, 40, 50 kA — that is not below the calculated value, with peak withstand following at 40, 50, 63, 80, 100 or 125 kA. Rated current is chosen separately from 630 to 3150 A against circuit duty and does not follow the fault level.

A complete order designation is KYN28A-12 followed by four positions: the primary scheme number, which says whether the cubicle is an incomer, feeder, bus-tie or metering unit; the operating-mechanism code, D for magnetic and T for spring; rated current; and rated breaking current. The first two follow from where the cubicle sits in the system and from the control supply arrangement, and the last two are the results of the two questions above. Send the single-line diagram and circuit schedule and these four can be settled cubicle by cubicle.

Three things give a preliminary scheme: the single-line diagram, voltage class and rated current, and the system fault capacity. For a contract-grade quotation, add the cubicle count with each primary scheme, control supply type and voltage, metering and protection requirements, cable entry arrangement and cable sizes, communication interfaces, switchroom dimensions and any depth limit, and the standards and document list for the destination market.

Yes. Switchgear is supplied as equipment while an MV switchgear E-House or power module is supplied as an enclosure — the first is the panel itself, the second covers the enclosure, equipment layout, auxiliary systems and interface integration. Where a KYN28A-12 line-up goes inside a module as the primary equipment, ETENZ details the line-up arrangement, busbar connections and in-module interfaces, and the delivery boundary is settled once at contract stage.