Correct Use

Mechanical Conditions

Operating Stroke Setting

The setting of the stroke is very important for the Switch to operate with high reliability. The chart below shows the relationship among operating force, stroke, and contact reliability. To obtain high reliability from the Switch, the Switch actuator must be manipulated within an appropriate range of operating force. Be sure to pay the utmost attention when mounting the Switch.

Make sure that the operating body returns the actuator to the free position when the operating body has moved if the Switch is used to form a normally closed (NC) circuit. If the Switch is used to form a normally open (NO) circuit, the operating body must move the Switch actuator to a distance of 70% to 100% of the rated overtravel (OT) of the Switch, ensuring that the operating body pushes the actuator a sufficient distance without touching the Switch itself. For details, refer to Precautions for the relevant product.

If the stroke is set in the vicinity of the operating position (OP) or at the releasing position (RP), switching operation may become unstable.
As a result, the Switch cannot ensure high reliability. Furthermore, the Switch may malfunction due to vibration or shock.

If the stroke is at the total travel position (TTP), the momentary inertia of the operating body may damage the actuator or the Switch itself. Furthermore, the life of the Switch may be shortened.

Switching Speed and Frequency

The switching frequency and speed of a Switch have a great influence on the performance of the Switch. Pay attention to the following.

・ If the actuator is operated too slowly, the switching operation may become unstable, causing faulty contact or contact weld.

・ If the actuator is operated too quickly, the Switch may be damaged by shock.

・ If the switching frequency is too high, the switching of the contacts cannot catch up with the operating speed of the actuator.

・ If the operating frequency is extremely low (i.e., once a month or less frequent), a film may be generated on the surface of the contacts, which may cause contact failures.

The permissible switching speed and switching frequency of a Switch indicates the operational reliability of the Switch. The life expectancy of the Switch is based on operation under specific conditions regarding the switching speed and switching frequency. The life of the Switch, however, may vary even if the Switch is operated within the permissible switching speed and frequency ranges. Test a Switch sample under the actual conditions to ascertain its life expectancy.

Operating Condition

Do not leave the Switch actuated for a long time, otherwise the parts of the Switch may soon deteriorate and changes in its characteristic performance may result.

Electrical Conditions

Application of Switch to Electronic Circuits

The Basic Switch in switching operation may cause contact bouncing or chattering, thus generating noise or pulse signals that may interfere the operation of electronic circuits or audio equipment. To prevent this, take the following countermeasures.

・ Design the circuits so that they include appropriate CR circuits to absorb noise or pulse signals.

・ Use Switches incorporating gold-plated contacts for micro loads, which are more resistive to environmental conditions than standard Switches. (Ensure, however, that the load capacity is sufficient.)

Switches for Micro Loads

Use a dedicated Switch for micro loads, otherwise contact failures may result. Be sure to connect the Switch to a load within the permissible range. Even if the load is within the permissible range, the inrush current of the load may deteriorate the contacts, thus shortening the life of the Switch. Therefore, if necessary, insert the proper contact protective circuit.

Mechanical Conditions

Switching Method

The switching method has a great influence on the performance of the Switch. Consider the following before operating the Switch.

・ Design the operating body (i.e., the cam or dog) so that it will operate the actuator smoothly. If the actuator snaps backwards quickly or receives damage due to the shape of the operating body, its life expectancy may be shortened.

・ Make sure that no improper load is imposed on the actuator, otherwise the actuator may incur local abrasion. As a result, the actuator may become damaged or its life expectancy shortened.

・ Make sure that the operating body moves in a direction where the actuator moves. If the actuator is a pin plunger type, make sure that the operating body presses the pin plunger vertically.

Operate the actuator of a hinge roller lever or simulated hinge lever type in the direction shown below. Operating the actuator in the opposite direction may result in deformation of the lever.

・ Do not modify the actuator to change the operating position (OP).

・ If an external actuator is used as an operating object, check the material and thickness of the lever and make sure that the force imposed on the lever is within the permissible range.

Mounting

When mounting the Switch, pay attention to the following.

Securing

When securing the Switch, be sure to use the specified mounting screws and tighten the screws with flat washers or spring washers securely.

If the Switch housing is made of thermoplastic, the Switch housing may incur crack damage if it comes into contact with the spring washers directly. In that case make sure that the flat washers come into contact with the Switch housing as shown below.

・ Do not modify the Switch in any way, for example, by widening the mounting holes.

・ Do not subject the Switch to excessive shock or high-frequency vibrations when mounting as this may have an adverse effect on Switch performance.

Locking Agent

If glue or locking agent is applied, make sure that it does not stick to the movable parts or intrude into the interior of the Switch, otherwise the Switch may work improperly or cause contact failure. Some types of glue or locking agent may generate gas that has a bad influence on the Switch. Pay the utmost attention when selecting the glue or locking agent. Particular care is required with unsealed Switches. Glue or locking agent may intrude into the interior of the switch via the pushbutton or the terminals and cause faulty operation. Select the glue or locking agent carefully and be sure to apply it in appropriate places.

Wiring

Make sure that the lead wires are connected with no inappropriate pulling force and that the wires are supported securely.

Mounting Location

Be sure not to mount the Switch in locations where the Switch may be actuated by mistake.

Maintenance and Inspection

Make sure that the Switch is mounted in locations that allow easy inspection or replacement of the Switch.

Mounting Direction

When using a Switch of low operating force attached with a long lever, make sure that the lever is in the downward direction as shown below, otherwise the Switch may not reset properly.

Operation and Storage Environment

Oil and Water Resistance

The standard Switch is not water-resistant. Protect the Switch with appropriately when using the Switch in places with water or oil spray. If the Switch is exposed to water drops, use a sealed Switch.

Handling

Do not drop the Switch, otherwise the Switch may break or deform.

Do not apply oil, grease, or other lubricants to the sliding parts of the Switch, otherwise the actuator may not operate smoothly. The intrusion of oil, grease, or other lubricants into the internal part may cause faulty operation or contact failure.

Operating Environment

Do not install the Switch in any location or direction where the Switch resonates or continuous vibration or shock is imposed on the Switch. If continuous vibration or shock is imposed on the Switch, a contact failure, malfunction, or a decrease in life expectancy may be caused by abrasive powder generated from the internal parts. If excessive vibration or shock is imposed on the Switch, the contacts may malfunction or become damaged.

Do not use the Switch in locations with corrosive gas, such as sulfuric gas (H₂S or SO₂), ammonium gas (NH₃), nitric gas (HNO₃), or chlorine gas (Cl₂), or in locations with high temperature and humidity. Otherwise, contact failure or corrosion damage may result.

If the Switch is used in places with silicone gas, arc energy may attract silicon dioxide (SiO₂) to the contacts and a contact failure mayresult. If there is silicone oil, silicone sealant, a wire covered with silicone, or any other silicone-based product near the Switch, attach a contact protective circuit to suppress the arcing of the Switch or eliminate the source of silicone gas generation.

Be sure to use the Switch at temperature within the specified range. If the Switch is exposed to radical temperature changes or intense heat, the performance characteristics of the Switch may change.

Storage Environment

When storing the Switch, consider countermeasures (e.g., storing in a plastic bag) to prevent discoloration resulting from sulfidization of the terminals (silver-plated). Make sure that the location is free of corrosive gas or dust with no high temperature or humidity. It is recommended
that the Switch be inspected before use if it is stored for three months or more.