Flameproof gear-driven rotary limit switch for explosive atmospheres: 1:15 – 1:1578 revolution ratios, 2 / 3 / 4 cams, IP66, G20 cast-iron enclosure.
LIMITEX Rotary Type
Rugged and reliable, the LIMITEX rotary limit switch is used to control the movement of industrial machinery in potentially explosive areas. It operates as an auxiliary controller of electric motors through a power interface such as a contactor or PLC.
A worm gear and a helical toothed gear combined with one or more pairs of straight toothed gears transmit the movement from the input shaft to the output shaft. Revolution ratios result from different gear combinations between the input shaft and the cam-driven output shaft; standard ratios are 1:20, 1:25, 1:50, 1:75 and 1:100, with non-standard ratios available on request.
The external enclosure is made of G20 cast iron; transmission and gear driving shafts are AISI 316 stainless steel to prevent oxidation and wear, and the data nameplate is also stainless steel. Gear wheels and driving bushes are self-lubricating techno-polymer, and sintered bronze bushes moulded into the base optimise shaft rotation.
- Revolution ratios — 1:15 – 1:1578 (standard 1:20, 1:25, 1:50, 1:75, 1:100)
- Cam sets — 2, 3 or 4 switches; each cam accurately set by adjusting screws
- Switches — 1NO+1NC snap-action change-over contacts; NC contacts with positive opening
- Mounting — fixing feet; optional flange for direct coupling to the transmission; special output shaft dimensions on request
- Protection — IP66 · −40 °C to +60 °C · 1 million operations mechanical life
- Full stainless-steel body — available
Technical Specifications
| Max. power supply | 300 V AC |
|---|---|
| Max. current | 3 A |
| Rated frequency | 50 / 60 Hz |
| Max. rotation speed | 800 rpm |
| Utilisation category | AC-15, 250 V AC / 3 A |
| Thermal current / insulation voltage | 10 A / 300 V AC |
| Connections | 6.3 mm Faston taps |
| Cable entry | 1 × M20x1.5 · 1 × M25x1.5 · 1 × ½ NPT (cable glands not supplied) |
| Weight | 4.6 kg (feet) · 5.2 kg (flange and feet) |
Certifications
- Certificate — INERIS 13ATEX0020X · IECEx INE 13.0051X
- Mining — I M2 Ex d I Mb (ATEX) · Ex d I Mb (IECEx)
- Gas, Zones 1 and 2 — II 2 G Ex d IIB T6 Gb or Ex d IIC T6 Gb
- Dust, Zones 21 and 22 — II 2 D Ex tb IIIC T85 °C Db IP66
- Standards — EN / IEC 60079-0, 60079-1, 60079-31; EN 60204-1, 60204-32, 60947-1, 60947-5-1, 60529