Shaft Extensions + Couplers
Sprecher + Schuh shaft extensions connect an L7 disconnect switch mounted on the enclosure backplate to a switch handle assembly on the enclosure door. The right extension is set by one measurement, the mounting depth, and by the handle type you are using. This category also includes end shafts, changeover inserts, and the 6-pole mechanical couplings that join two L7 switches. Automation Distribution carries all three Sprecher + Schuh shaft extension systems: modular plastic, adjustable metal, and R-type.
Shaft extensions are for LA7 base-mount switches only. LE7 front-mount switches mount directly behind the handle and use the standard 44 mm end shaft that ships with the switch body.
How do you size an L7 shaft extension?
Size every L7 shaft extension by mounting depth: the distance from the inside mounting surface of the enclosure to the outside surface of the enclosure cover.
- Measure mounting depth and convert to millimeters if needed (inches x 25.4).
- For 6-pole switches, deduct 25 mm. Sprecher + Schuh sizing tables are based on 3- and 4-pole switch bodies.
- For DIN rail mounting, deduct the rail offset, for example 2.5 mm for DIN 46277 rail.
- Choose the extension system based on your handle type and required length, then select the component that covers your mounting depth for your LA7 switch body.
Which shaft extension system do I need?
| System | Use with | How it works | Key catalog numbers |
|---|---|---|---|
| Modular plastic | Standard LFS switch handle assemblies | 24 mm polycarbonate modules snap together without tools, up to 144 mm of added length. An end shaft connects the last module to the handle. | LA2-G2853 modules (2 per pkg); end shafts LA2-G2830 / L7-G3687 (44 mm), LA2-G3194 / L7-G3707 (52 mm), LA2-G3195 (57 mm) |
| Adjustable metal | Standard LFS switch handle assemblies | Adjustable length with a built-in door interlock and a padlock hasp for locking out the switch after the enclosure is opened. All hardware included. | LA2-G3393 (110 to 235 mm), LA2-G3394 (230 to 350 mm) |
| R-type | Type R handles only (LA7-SB, LA7-SY, L11-PB, L11-PY) | Fixed-length shafts, or an adjustable shaft up to 368 mm (14.5 in). Required for Type R handles. | LA7-S-67, LA7-S-90, LA7-S-97, LA7-S-115; adjustable LA7-S1-P; LA7-NS-P kit (L11-S1 shaft ordered separately) |
Modular system sizing rule
With no extension modules, the standard 44 mm end shaft covers these mounting depths: 57.5 to 63.5 mm (LA7-16), 66.5 to 72.5 mm (LA7-25/32), 79.5 to 84.5 mm (LA7-40/63), and 96 to 102 mm (LA7-80/100). Each extension module adds 24 mm. The 52 mm and 57 mm end shafts fill the gaps between those ranges, up to six modules.
Metal and R-type shaft mounting depths (mm)
| Catalog number | LA7-16 | LA7-25/32 | LA7-40/63 | LA7-80/100 |
|---|---|---|---|---|
| LA2-G3393 | 168 to 299 | 173 to 304 | 186 to 317 | 203 to 334 |
| LA2-G3394 | 288 to 414 | 293 to 419 | 306 to 432 | 323 to 449 |
| LA7-S-67 | 84.5 to 108.5 | 93.5 to 117.5 | 117.5 to 131.5 | 123.5 to 147.5 |
| LA7-S-90 | 107.5 to 131.5 | 116.5 to 140.5 | 130.5 to 154.5 | 146.5 to 170.5 |
| LA7-S-97 | 114.5 to 138.5 | 123.5 to 147.5 | 137.5 to 161.5 | 153.5 to 177.5 |
| LA7-S-115 | 132.5 to 156.5 | 141.5 to 165.5 | 155.5 to 179.5 | 171.5 to 195.5 |
| LA7-S1-P | 130 to 385 | 144 to 399 | 157 to 412 | 174 to 429 |
The minimum LA2-G3393 depth can be reduced a further 55 mm by cutting the plastic sleeve and metal shaft. Specifications per the Sprecher + Schuh SSNA2026 catalog, Section L1.
End shafts, inserts, and changeover switches
Every L7 switch body ships with a 44 mm end shaft. LE7-16 through LE7-32 three-pole switches get a plastic end shaft; larger three-pole, 6-pole, and changeover switches get metal. Replacement LE7 end shafts are L2-G3380 (plastic) and L7-G3688 (metal), sold in packages of five.
Three-pole changeover switches used with an adjustable metal shaft extension require insert LA2-G3399 for three-position switching. Lockout at the switch is not possible in that configuration, so specify a lockable Type E or Type L handle for lockout outside the enclosure.
6-pole mechanical couplings
A mechanical coupling joins two three-pole L7 switches, front or base mount, into a single 6-pole switch operated by one handle. Each coupling includes 44 mm metal end shafts for both LE and LA switches.
| For use with | Catalog number |
|---|---|
| LE7-16 | L7-G3821 |
| LE/LA7-25 and 32 | L7-G3660 |
| LE/LA7-40 and 63 | L7-G3661 |
| LE/LA7-80 and 100 | L7-G3662 |
Coupled LE7 front-mount switches must use 48 x 48 or 64 x 64 mm handles; the 88 mm and 90 mm handles are not compatible with the coupling. Coupled LA7 base-mount switches can use any applicable LFS handle. A coupled pair keeps 1 through 6 terminal markings on each switch; for 1 through 12 markings, order a factory 6-pole switch instead. Couplings are not available for changeover switches.