Outdoor Withdrawable Fix Type Vacuum Circuit Breaker: Two Versions, One Frame

There is a name in this product that causes more argument than any other in medium-voltage switchgear: outdoor withdrawable fix type vacuum circuit breaker. It reads like two different machines, and buyers split into two camps over what it means. One camp thinks withdrawable is the product and fix type is leftover wording from a catalogue. The other thinks fix type is the product and withdrawable is an upgrade you can bolt on later. Neither is quite right.

What the wording actually describes is one frame with two build options. The mechanism, the vacuum interrupter chambers and the primary contacts are the same family of parts. What changes is how the breaker sits in its cubicle: whether it can be withdrawn from the compartment for service, or whether it is fixed into the compartment for the life of the installation. Everything else on the datasheet stays the same.

That distinction matters commercially, not just mechanically. A withdrawable unit can be replaced in a switchgear lineup without the panel being taken apart, which is why they show up in indoor switchgear rooms, mining switch rooms and mobile substations. A fixed unit costs less per bay and takes less depth, which is why it still turns up in outdoor kiosks and compact prefabricated stations. Ask for a quotation that does not state which one you are getting and the two will not be comparable.

Here is what the VS1 VBM7 outdoor withdrawable fix type vacuum circuit breaker actually specifies, and what the supplier's own datasheet leaves out.

WITHDRAWABLE AND FIXED ARE A STRUCTURE CHOICE, NOT A QUALITY LADDER

The first thing to clear up is that neither version is the better one. They solve different problems. A withdrawable breaker is not a premium fixed breaker; it is a breaker you can take out. If your maintenance strategy depends on swapping a unit in under an hour with the panel live, withdrawable is the answer. If your site is a fixed kiosk that will not be opened for years, fixed is the cheaper and equally sound answer.

Second, the two options are quoted against the same ratings sheet. The rated voltage, rated current, breaking capacity and mechanical life do not change between them. If a supplier sends you two quotations with different ratings attached, that is not withdrawable-versus-fixed pricing; that is two different products, and you should ask which one you are actually being offered.

Third, the wording matters in writing. On a quotation and on the packing list, the phrase outdoor withdrawable fix type vacuum circuit breaker should appear as the product designation, with the version you mean spelled out immediately after it. The catalogue title carries both words because the manufacturer builds both. Your PO should carry only the one you want.

THE VS1 VBM7 RATINGS THIS DATASHEET ACTUALLY PUBLISHES

Rated voltage is 12kV. Rated current runs from 630A to 1250A. Breaking capacity is offered at 20kA, 25kA and 31.5kA. The unit is three-phase, rated 50Hz, with a mechanical life of 10000 operations. The mechanism designation given for this version is the BCD curve.

On the closing circuit, this build is specified with a 24VDC closing coil. That is a customer input rather than a fixed catalogue item, so confirm it against your own control supply before the order is placed, not after.

Two things this datasheet does not give you, and which you should ask for in writing before you rely on them. First, the insulation level and the rated short-time withstand values are not stated in the material supplied, so anyone quoting you a withstand figure is sourcing it from somewhere else. Second, the datasheet carries a 400A figure in its product title while the rated current line publishes 630A to 1250A; treat the 630A-1250A range as the operating envelope and confirm the exact frame rating for your bay.

It is worth saying plainly that a few voltage classes appear in supplier titles for this family of breaker without appearing in the ratings table. Where the table shows 12kV, this article stays at 12kV. If your site needs a different class, ask for that datasheet separately instead of carrying a number over from a listing.

THE SITE CONDITIONS THAT DECIDE WHETHER IT GOES OUTDOORS AT ALL

Outdoor is not a decorative word here; it comes with an environmental envelope, and this one is published. Ambient temperature: not higher than +40 °C and not less than -15 °C. Altitude: not exceeding 1000m. Relative humidity: daily average not more than 95%, monthly average not more than 90%. Earthquake intensity: not more than ten.

The stated site restrictions are equally concrete: no fire or explosion hazard, no serious filth, no chemical corrosion, and no intense vibration. A coastal plant with salt-laden air, a rooftop installation above a heavy road, or a site near a large compressor house should be checked against that list before the order, because those three conditions are what the datasheet is excluding.

Origin is Zhejiang, China. The minimum order quantity is 1 piece, and the listed price band is US$3,497-3,499 with a sample price of US$3,479. The brand name on both the datasheet and the nameplate is XIAOPAI.

LOGISTICS, AND THE TWO FIGURES TO CONFIRM BEFORE SHIPMENT

The single package size is published as 84 x 37 x 64 cm. That is the number to use when you are checking whether the breaker will physically go through the access opening of your kiosk, and it is worth checking before the crate arrives rather than after.

The gross weight field in the same material is not consistent with an 84 x 37 x 64 cm package, and we are not going to publish a corrected figure we cannot stand behind. Treat the package dimensions as published and ask the supplier for the confirmed shipping weight along with the crate type before the quotation is signed. If freight is quoted on volumetric weight, that number matters to your landed cost.

One further item belongs on the same list. This datasheet carries no readable outline mounting dimensions. Ask for the dimension drawing against the specific frame and version you are ordering, and tie it to the drawing number on the purchase order, the way a high voltage vacuum circuit breaker frame is normally quoted. The full model list sits on our XIAOPAI vacuum circuit breaker page if you need it in one place.

WHAT TO PUT IN WRITING BEFORE YOU ORDER

Put the version in the product designation. Write outdoor withdrawable fix type vacuum circuit breaker and then state withdrawable or fixed, so there is no argument later about which frame you received.

Put the ratings on the order too: 12kV, three-phase, 50Hz, the rated current you are taking from the 630A-1250A range, and the breaking capacity you are buying against the 20kA, 25kA and 31.5kA options. The insulation level and the short-time withstand figures are not published in this material, so ask for them in writing before you compare two offers against each other.

Put the closing coil supply in the order as 24VDC, and put the site conditions in the order as the envelope you are working within.

And put the two logistics figures in the order as an explicit request for written confirmation: package size 84 x 37 x 64 cm as published, and shipping weight to be confirmed. For comparison, how the ratings shift between voltage classes and when service access, not ratings, drives the structure decision both come up in the same conversations.

ONE LINE FOR THE RECORD

The VS1 VBM7 from XIAOPAI - Wenzhou Xiaopai Electric Power Technology - is a 12kV three-phase vacuum circuit breaker offered in withdrawable and fixed versions, 630A to 1250A, with 20kA, 25kA and 31.5kA breaking capacity, 50Hz, and a mechanical life of 10000 operations. Made in Zhejiang, China, minimum order 1 piece, listed at US$3,497-3,499, single package 84 x 37 x 64 cm. Site envelope: +40 °C to -15 °C, altitude not exceeding 1000m, and no fire, explosion hazard, serious filth, chemical corrosion or intense vibration. Full model range at https://www.cnxiaopai.com/sys-pd/22.html.