Snap-action switch S850 – Double break contact for twice the reliability

Double break contact with self-cleaning double contacts, galvanic isolation and positive opening

S850 O6A2 a Snap-action switch S850 with pushbutton and screw connections
S850 O6A2 b Snap-action switch S850 with roller lever and screw connections

The S850 snap-action switch can open two galvanically isolated safety circuits with one actuation. Equipped with one positive opening for both break contacts, the S850 represents a favourable solution for control system engineers who want to increase the safety level of machines and systems without investing in additional hardware, installation or programming. This high-quality microswitch is suitable for safety-related applications as outlined in DIN EN ISO 13849-1.


Double break contact with double break, galvanically isolated

Double break contact with two galvanically isolated contact bridges. Both contact pairs are opened when the snap-action switch is actuated.

Continuous thermal current up to 10 A; disconnecting medium to high power ranges

A contact bridge spreads the breaking capacity over two contact points. The contact material is silver. For the switching of high direct currents, we recommend blow magnets for preventing electric arcs (optional).

Both break contacts with positive opening

If the break contacts fuse in the event of a short circuit, the catch spring can no longer open. It is nevertheless opened reliably via the lever of the positive opening. This is a positive opening as outlined in DIN EN 60947-5-1, annex K.

Self-cleaning double contacts

In every switching process, the contact bridges rub in a defined fashion on the V-shaped fixed contacts and remove corrosion and combustion residue. Permanently low contact resistances ensure a high level of contact reliability throughout the service life.

Reliable switching of low currents

With self-cleaning silver contacts, small currents can be connected reliably and frequently. In chemically aggressive environments and with low switching frequencies, we recommend gold contacts.

Dimensions 50.2 x 38 x 12 mm (L x H x W)

This is the maximum dimensions of the housing. The dimensions of the actuator and of the connections must be added. For all dimensions and drawings please refer to the following product catalogue:



Electrical Data
Contact configurationDouble NC contact switch with 4 terminals, positive opening operation, wiping action, and 2 galvanically isolated contact bridges
Conv. thermal current Ith EN6094710 A at T = 85°C
Conv. thermal current Ith UL5085 A at T = 85°C
Rated insulation voltage Ui EN60947400 V
Rated insulation voltage Ui UL508300 V
Pollution degree IEC 60947PD 3
Pollution degree UL508PD 3
Rated impulse withstand voltage Uimp4 kV
Utilization category IEC 60947AC-15, 230 VAC/1.5 A / DC-13, 24 VDC/1.5 A
Utilization category UL508240 V AC General Purpose / 4 A
IP rating: contacts/terminalsIP40/IP20
Contact materialSilver or gold-plated silver
Short-circuit protection10 A gG
Actuators, operating positions
ActuatorPhush button, roller lever
Free position8.85 ±0.15 (push button)
Operating position6.60 ±0.25 (push button)
Release position7.80 ±0.25 (push button)
Total positive opening travel5.80 (push button)
Total travel position< 5.65 (push button)
Movement differential (between operating and release position)1.20 (typical, push button)
Mechanical data
Front mountyes, front mounting by nut retainers M3
Ganging (side mount)yes, side mount
Vibration resistance15 g (10 … 500 Hz all directions (without aux. actuator at 0.1 ms max. opening time)
Shock resistance30 g, half sinus (without aux. actuator at 0.1 ms max. opening time)
Housing materialPC, green, transparent
Mechanical endurance1.5 million cycles min.
Temperature range-55°C ... +85°C
NoteData valid for new switches with silver contacts

Related Downloads

Catalogue D50 – Snap-action switches S850
Snap-action switches with double NC contacts, positive opening operation and wiping action
Safety instructions snap-action switches
Snap-action switches S800 / S804 / S814 / S818 / S819 / S820 / S826 / S834 / S840 / S845 / S846 / S847 / S850 / S870 / S880 / S926 / S947 / S970
Safety instructions snap-action switches / Supplementary details
Snap-action switches S800 / S804 / S814 / S818 / S819 / S820 / S826 / S834 / S840 / S845 / S846 / S847 / S850 / S870 / S880 / S926 / S947 / S970
Manual SE-M
Snap-action switches S800 / S804 / S814 / S818 / S819 / S820 / S826 / S840 / S845 / S846 / S847 / S850 / S870 / S880 / S926 / S947 / S970 — Installation and Maintenance Instructions
/en/products/snap-action-switches/thank-you/Snap-action switch S850 Snap-action switches

Your quick contact to us!

If you have any questions, suggestions or other concerns, please let us know. Please fill out our short contact form.