In a Saudi MV room the choice is settled by numbers a tender can check: the connection voltage, the fault level at 60 Hz, the LSC and partition class, the arc class and the room's own heat, dust and height. The insulating gas comes last, and it is a chemistry with a GWP, not a brand.
Four decisions to carry into the next MV switchgear specification you write.
Above 4 MVA a Saudi customer is connected at 13.8 or 33 kV and builds and runs the substation. SEC's 2004 planning standard uses 20 kA and 25 kA for 1 s; size to the fault level for your own connection, plus your motors and generators. At 60 Hz, with the standard 45 ms time constant, the peak withstand is 2.6 times that current.
IEC 62271-200 grades AIS, SF6 GIS and SF6-free alike, panel by panel. IEEE metal-clad and IEC LSC2B-PM are compared, not interchangeable. The arc class is optional: write it in full, for example IAC A FLR 20 kA 1 s, with the room it was tested in.
IEC 62271-1 rates current at 40 °C. With the 2007 text's limits and n = 2, bare copper contacts keep 85% at 50 °C; the 2017 edition raised some limits, so ask the maker for the current at your ambient. ABB's guide shows a 1250 A feeder at 800 A in a dust-tight enclosure.
Twelve panels, envelope only: SF6 GIS without a relief duct is 53% of AIS at 24 kV and 61 to 76% at the 17.5 kV class used for 13.8 kV. Clean-air GIS matches SF6 GIS only with its duct. Most of the room saving is the aisle.
Every row names its document. Where the source is old, a mirror copy, or a value was read only in an earlier edition, the row says so.
| Requirement | Value | Source |
|---|---|---|
| Saudi MV levels | 13.8 kV and 33 kV | SEC Distribution Planning Standard, 2004, 2.1 |
| MV connection band | above 4 up to 25 MVA, customer substation | SERA Electricity Service Guide, art. 11 |
| Planning fault level | 20 kA at 13.8 kV, 25 kA at 33 kV, 1 s | SEC DPS 2004, Table 4.1 (dated; size to the connection study) |
| Peak withstand factor | 2.6 at 60 Hz, 2.5 at 50 Hz, 45 ms time constant | IEC 62271-1:2017 5.7, Table 5 (value read in the 2007 text, 4.6) |
| Rated voltage class | 17.5 or 15 kV for 13.8 kV; 36 or 38 kV for 33 kV | IEC 62271-1:2017 5.2, 5.3, Tables 1 and 2 |
| Standard and edition | IEC 62271-200:2021+AMD1:2024, edition 3.1 | IEC webstore |
| Service continuity | LSC1, LSC2, LSC2A, LSC2B, per functional unit with a connection compartment | IEC 62271-200 AMD1, 3.6.101 |
| Metal-clad comparison | IEEE metal-clad compared with IEC LSC2B-PM; not interchangeable | IEEE C37.20.2-2025; IEC 62271-200:2003 Annex C |
| Arc class, written | IAC A FLR 20 kA 1 s, with the tested room; optional | IEC 62271-200, 5.103, Annex A |
| Highest IAC, catalogues reviewed | 50 kA at 17.5 kV; 31.5 kA at 24 and 36 kV; 1 s | Siemens HA 25.74 (2023), HA 25.72 (2025); ABB 1VCP000138 Rev Z (2026) |
| Reference ambient | 40 °C, 24 h mean 35 °C | IEC 62271-1:2017 4.1.2 (35 °C read in the 2007 text and Siemens HA 25.73) |
| Current kept at 50 °C | 85% bare copper, 92% silver-plated contacts (2007 limits, n = 2) | IEC 62271-1, 2007 8.2 (2017: 9.4, Table 14 revised) |
| Twelve panels at 24 kV | AIS 15.0 m²; SF6 GIS 7.9 m² without duct, 8.8 m² with; clean air 8.8 m² | ABB, Siemens dimension sheets |
| SF6 GWP-100 | 24,300 on AR6; 23,500 on AR5 | IPCC AR6 Table 7.SM.7 |
| EU switchgear rule | putting into operation: to 24 kV from 2026, to 52 kV from 2030; derogations apply | Regulation (EU) 2024/573, Art. 13(9) to 13(18) |
In the order a Saudi design review meets them, from the connection agreement to the gas.
SERA's Electricity Service Guide connects a load above 4 MVA and up to 25 MVA at medium voltage, and the customer then builds, operates and maintains his own substation. The Saudi Arabian Grid Code lists what the user must declare for that switchgear: rated voltage, rated current, symmetrical and asymmetrical short-circuit current, interrupting current and time, and impulse level. SEC's Distribution Planning Standard uses 20 kA at 13.8 kV and 25 kA at 33 kV for 1 s. Those are planning values in a document dated 2004 and read through a third-party copy, not the fault level at your connection. Take that from SEC for the point of connection, add your own motors and generators in a short-circuit study (for example to IEC 60909-0), and confirm it in the connection agreement, which is the number that binds.
An interlock-controlled compartment opens only when the parts inside are isolated and earthed, and the LSC category says what else stays live while it is open. Since AMD1:2024, only a functional unit with a connection compartment carries an LSC category, so a bus coupler without one has none. Schneider's 2022 guide grades its air-insulated MCset LSC2B-PM, its SF6 GIS LSC2-PM and its clean-air GIS LSC2-PM: the same scale for all three media. The 2003 edition of IEC 62271-200 equated ANSI metal-clad with LSC2B-PM; edition 3.0 has no such annex, and IEEE C37.20.2-2025 is a separate standard with its own tests, so treat the two as a comparison, not as interchangeable certificates.
One air-insulated range is rated 40 kA for 3 s short-time withstand and 40 kA for 1 s internal arc. The arc test current equals the rated short-time current unless the maker states a lower one, but the durations are separate ratings. Writing 40 kA 1 s without saying which rating it is leaves the bidder to choose. A complete arc class names the accessibility type (A or B), the classified sides (F, L, R), the current and the duration, and the installation it was tested in: IEC 62271-200 Annex A draws the ceiling height and the exhaust arrangement as part of the test, and one maker's ceiling table (NXAIR, 2023) applies to that product family only.
IEC 62271-1 rates current at 40 °C. The 2007 text (clause 8.2; 9.4 in the 2017 edition, whose wording was not read here) gives an equation, not a table: Is = Ir [(θmax − θa) / Δθr]1/n, with n = 2 as the conservative exponent. With the 2007 Table 3 limits, bare copper contacts keep 85% at 50 °C and 76% at 55 °C. The 2017 edition's Table 14 raised some limits (per IEC TR 60943), so treat these as a conservative illustration and ask the maker for the rated current at the room's maximum ambient. The 2007 text's very hot climate class runs to 55 °C, but only when the enquiry names it, and the standard assumes no dust or salt unless the user says otherwise. SEC itself rates its overhead lines at 50 °C.
Compare like with like. SF6 GIS at 1100 mm deep has no rear relief duct; with the duct it is 1225 mm, the same envelope as the clean-air GIS, which is then 59% of the AIS lineup at 24 kV rather than 53%. At 24 kV the GIS room is 875 mm shallower than the AIS room, and 400 mm of that is the aisle a withdrawable truck needs. At 12 kV a 500 mm ABB panel is already the footprint of a 600 mm GIS panel. None of the catalogues reviewed publishes a GIS price ratio; the only official figure found is the European Commission's estimate of 3.6% extra sector cost for SF6-free switchgear, which is not a per-panel premium.
In the documents reviewed to 9 October 2026 (the Saudi Arabian Grid Code of May 2024, SERA's Electricity Service Guide and the Ozone Secretariat profile) no Saudi rule restricting SF6 was found; GCC instruments and SEC procurement specifications were not reviewed. The Kigali amendment Saudi Arabia accepted in 2025 covers HFCs only. The EU prohibits putting new F-gas switchgear into operation up to 24 kV from 2026 and to 52 kV from 2030, with derogations: if a tender draws no bid for F-gas-free switchgear (or, in the first two years, bids from only one maker of it), a medium with GWP below 1000 may be used, and if no bid offers that either, any medium including SF6 (Art. 13(11) and 13(12)); orders placed before 11 March 2024, some extensions, relocation and spare parts are also excepted, and the operator notifies the authority. From 2035 only reclaimed or recycled SF6 may be used for servicing. Switchgear already in service needs no periodic leak check if any one of three conditions holds (Art. 5(1)): its tested leakage rate is below 0.1% a year, as stated in the manufacturer's technical specification, and it is labelled accordingly (the label requirement is in Art. 12); it has a pressure or density monitoring device with an automatic alert while in operation; or it contains less than 6 kg of Annex I F-gases. In a sealed compartment the pressure rises with the room: one fluoronitrile mixture goes from 8.97 bar at 20 °C to 9.65 bar at 40 °C.
Five lines, each naming a document, a quantity and a unit. None of them can be answered with a brand.
a. Metal-enclosed to IEC 62271-200:2021+AMD1:2024 and IEC 62271-1:2017+AMD1:2021, 60 Hz, rated 17.5 kV (or 15 kV) for 13.8 kV, 36 kV (or 38 kV) for 33 kV.
b. Short-time current and duration from the connection study; peak at 60 Hz stated. IAC: type, sides, kA, s, for this room's ceiling and relief route.
c. LSC2B-PM for breaker feeders, LSC and partition class stated per functional unit.
d. Rated current declared at the room's maximum ambient; altitude, dust and salt stated in the enquiry.
e. Insulating medium named by chemistry and GWP basis; tested leakage rate, density alarm per compartment, gas handling to IEC 62271-4.
Line d is the easiest to leave out. It decides whether a 1250 A panel is a 1250 A panel in August.
From our Dammam factory, NLC supplies and integrates Schneider Electric MV ranges up to 24 kV, which covers the 13.8 kV network. Put the connection voltage, the connection agreement's fault level and the room's maximum ambient in the enquiry, and ask for the LSC, partition and arc class of every functional unit.
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