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 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.

Features

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:

(d50_en.pdf)

Specifications

Electrical Data

Contact configuration	Double NC contact switch with 4 terminals, positive opening operation, wiping action, and 2 galvanically isolated contact bridges
Conv. thermal current I_th EN60947	10 A at T = 85°C
Conv. thermal current I_th UL508	5 A at T = 85°C
Rated insulation voltage U_i EN60947	400 V
Rated insulation voltage U_i UL508	300 V
Pollution degree IEC 60947	PD 3
Pollution degree UL508	PD 3
Rated impulse withstand voltage U_imp	4 kV
Utilization category IEC 60947	AC-15, 230 VAC/1.5 A / DC-13, 24 VDC/1.5 A
Utilization category UL508	240 V AC General Purpose / 4 A
IP rating: contacts/terminals	IP40/IP20
Contact material	Silver or gold-plated silver
Short-circuit protection	10 A gG

Actuators, operating positions

Actuator	Phush button, roller lever
Free position	8.85 ±0.15 (push button)
Operating position	6.60 ±0.25 (push button)
Release position	7.80 ±0.25 (push button)
Total positive opening travel	5.80 (push button)
Total travel position	< 5.65 (push button)
Movement differential (between operating and release position)	1.20 (typical, push button)

Mechanical data

Front mount	yes, front mounting by nut retainers M3
Ganging (side mount)	yes, side mount
Vibration resistance	15 g (10 … 500 Hz all directions (without aux. actuator at 0.1 ms max. opening time)
Shock resistance	30 g, half sinus (without aux. actuator at 0.1 ms max. opening time)
Housing material	PC, green, transparent
Mechanical endurance	1.5 million cycles min.
Temperature range	-55°C … +85°C
Note	Data valid for new switches with silver contacts