General Information
General Information
31
Switch Trouble and Corrective Action
Type
Location
of failure
Failure
Possible cause
Corrective action
Failures
l t d t
Contact
Contact
f il
Dust and dirt on the contacts.
Remove the cause of the problem, place
th
it h i
b
l d
related to
electrical
characteristics
failure
Water or other liquid has penetrated into a
switch.
p
, p
the switch in a box, or use a sealed
switch.
characteristics
Chemical substances have been generated
on the contact surface due to the
atmosphere containing chemical corrosive
gas.
Use a switch having contacts with high
environmental resistivity (such as gold or
alloy contacts).
Chemical substances have been generated
on the contact surface when the switch
switches a very low load.
Solder flux has penetrated into the switch.
Review the soldering method or use a
sealed or flux-tight switch.
Silicon gas exists near the switch.
Remove the material generating gas, or
adjust contact capacity to prevent
formation of silicon compounds on the
contacts.
Malfunction
The contacts are separated from each other
by vibration or shock.
Use a switch having a high contact force
(generally a high OF).
Contact
welding
The load connected to the switch is too high.
Switch the load with a high-capacity relay
or magnetic relay or insert a contact
protection circuit.
Insulation
degradation
(b
i
)
Contacts have been melted and scattered
by arc.
Switch the load with a high-capacity relay
or magnetic relay.
deg ada o
(burning)
Water has penetrated into the switch
because the switch has been used in an
extremely hot environment.
Remove the cause of the problem, place
the switch in a box, or use a sealed
switch.
Liquid has penetrated into the switch and
been carbonized by arc heat.
Failures
related to
mechanical
h
t i ti
Actuator
Operating
failure
The sliding part of the actuator has been
damaged because an excessive force was
applied on the actuator.
Make sure that no excessive force is
applied to the actuator, or use an auxiliary
actuator mechanically strong.
characteristics
Foreign material like dust, dirt and oil has
penetrated into the switch.
Remove the cause of the problem or place
the switch in a box.
The actuator does not release because the
operating body is too heavy.
Use a switch having a higher OF.
The switch is loosely installed and thus does
not operate even when the actuator is at the
rated OP.
Secure the switch.
Low
d
bilit
The shape of the dog or cam is improper.
Change the design of the dog or cam.
durability
The operating method is improper.
The operating speed is too high.
Review the operating stroke and operating
speed.
Damage
A shock has been applied to the actuator.
Remove the cause of problem or use a
switch mechanically strong.
The caulked part is not good enough or the
assembled condition is poor.
Replace the switch with a new one.
Deformation or drop-out
Actuator was subjected to an excessive
force and force from an inappropriate
direction.
Review the handling and operating
method.
Mounting
section
Damage
Screws have not been inserted straight.
Check and correct screw insertion
method.
sec o
The mounting screws were tightened with
too much torque.
Tighten the screws with an appropriate
torque.
The mounting pitch is wrong.
Correct the pitch.
The switch is not installed on a flat surface.
Install the switch on a flat surface.
Terminal
Damage
An excessive force was applied to the
terminal while being wired.
Do not apply an excessive force.
The plastic part has been deformed by
soldering heat.
Reduce the soldering time or soldering
temperature. (Refer to the information
given under
Precautions
for that model.)
