Where to fix the opener
on your swing gate.
Measure two distances on the pillar and get the bracket positions in centimetres, with a drawing. For Key Automation RAY, STAR, VEGA, RÉVO and MEWA openers using the tables in their manuals, and for UND underground motors.
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What you measure and what the letters mean
How to measure
Hinge → pillar
From the centre of the hinge, straight to the face of the pillar.
- C
- From the centre of the hinge, square to the face of the pillar where the bracket is fixed. This is what you measure.
- A
- How far behind the hinge, along the pillar, the rear bracket goes (the opener axis for arm openers).
- B
- How far in from the hinge the rear bracket pivot sits. Key recommends keeping A and B as close to each other as possible.
- E
- Where the front bracket is fixed on the leaf, measured from the hinge.
The two mistakes that cause the trouble
Measuring from the wrong point
Every distance is measured from the centre of the hinge, where the gate turns. Measure from the edge of the gate or the pillar and the rear bracket ends up in the wrong place: the gate does not open fully or the opener strains.
Hinge far from the pillar
The bigger C gets, the smaller the angle a linear or piston opener can reach. Past a point you need a recess in the pillar or an articulated arm opener. The calculator tells you how deep the recess must be before you start.
Openers covered
Tap an opener's drawing for all the installation figures, or download them as a PDF along with Key's manual.
- RAY 252424V · 3 m · 500 kg
- RAY 3024 FAST24V · 3 m · 300 kg
- RAY 40230V · 4 m · 600 kg
- STAR PS-300FA230V · 3 m · 500 kg
- STAR PS-400-24V24V · 5 m · 600 kg
- STAR PS-400FA230V · 5 m · 600 kg
- STAR302424V · 3 m · 400 kg
- VEGA230V · 4 m · 250 kg
- RÉVO REP202424V · 2.3 m · 250 kg
- MEWA SN50 SX/DX230V · 4 m · 800 kg
- UND2230V · 3.5 m · 600 kg
- UND302424V · 3.5 m · 600 kg
- UND10230V · 3.5 m · 600 kg
- UND2424V · 3.5 m · 600 kg
- UND24 FAST24V · 3 m · 300 kg
Frequently asked questions
What are dimensions A and B on a swing gate opener?
They are the position of the rear bracket. A is the distance from the hinge axis along the pillar and B the distance from the hinge axis inwards. Together they decide how far the gate opens. Key recommends A and B as close to each other as possible.
Where do I measure from?
Always from the centre of the hinge, the axis the gate turns around. Not from the edge of the gate and not from the pillar.
What if the hinge is far from the pillar?
With a large C a linear or piston opener opens less. Either cut a recess into the pillar so C gets smaller, or fit an articulated arm opener. RÉVO works with C up to 20 cm. The calculator shows how much C must shrink for the angle you need.
How far does a swing gate opener open?
It depends on the rear bracket position. According to Key's tables, RAY reaches 110-120°, STAR PS-400 up to 127°, RÉVO up to 120° and MEWA up to 115°, when the pillar allows it. The UND underground motor opens up to 100°, more with the OP100 kit.
Can I automate a gate that opens outwards?
Yes, with RAY and the EXRB accessory, or with STAR PS-400 when C is 14 cm or more. For STAR3024, STAR PS-300, VEGA, RÉVO, MEWA and the UND underground motors the manual gives no outward installation.
At what height do the brackets go?
On RAY both brackets go at the same height. On STAR the front bracket goes 6.5 cm lower than the rear one. On RÉVO the wall bracket goes 8 mm below the line of the leaf bracket.
Where does the box of an underground motor go?
With its pivot exactly under the hinge axis, centred on the gate line. Key's foundation box for UND is 40.3 cm × 32.8 cm, 16.4 cm deep, and reaches 6.7 cm behind the axis, towards the pillar. It is set in concrete, level, with drainage.
Do I need mechanical stops?
Yes. Key requires the gate to have stops in the open and closed positions. The installation tables are given without the opener's own limit stops, so you set the opening stop at the end, with the gate where you want it.