The thermal cutoffs (TCO) are non resetting, thermally sensitive, single pole, normally
closed devices and are intended to be used in appliances.
 

Note that the TCO shall be connected at the readily detectable location when abnormal
conditions such as thermostat failure, fan failure, locked rotor, dry operation, etc.,
occurred in the appliance.

TCO is designed to lessen the heat created from TCO itself, but there may be a difference
between the ambient temperature and operating temperature of TCO due to wrong connection
method.

In order to minimize the difference between ambient temperature and operating temperature
of TCO, it is recommended that the creation of heat can be minimized around the TCO
connected area under normal operating condition, but the heat generation can be
maximized at TCO connected area under abnormal condition.

i) Each TCO has specific electrical and temperature ratings. Each TCO must be used within
   the prescribed ratings. These ratings include Rated Function temperature(TF) ,Holding
   Temperature(TH) ,Maximum Temperature (TM), and the electrical ratings.

ii) It is recommended the TCO connection shall be selected at the location in the end-use
    appliances where the undue stresses due to the vibration or other movement of parts
    does not apply.

iii) TCO shall be the location not coming into the liquids and high humidity in certain
    appliances like coffee makers.

iv) The end product should be designed so that TCO does not get any unusual condition
    exceeding its Maximum Temperature(Tm) in overshoot situation when TCO has
    functioned.

v) The end product should be designed so that TCO detects only the intended heat source.
    For example, in a heater, TCO does not be connected directly to heater -wire so that
    heat conductance through the lead wire does not accelerate the cut-off of the TCO.

vi) Avoid all heat sources except the heat being detected
    Although TCO are highly reliable, there are limits to the abnormal states with which
    a single TCO can cope. Further, if a TCO is damaged for some reason, it is possible
    that it will not break a current under abnormal conditions. If there is a possibility that
    personal or properly damage would arise if a circuit is not broken during abnormal
    equipment operation (i.e. when there is a high required safety level), it is effective to add
    one of more TCO with different Tf.

It is easy to bend the copper lead as it is flexible. But it is likely to be damaged or broken
if TCO lead is bent over 90 bending is repeated. When forming the lead, be careful not to
apply the forming force direct to TCO body.

i) Forming Sealant Lead Wire
   Bend the lead wire at least 4 mm away from the seal. The damage of the sealant worsen
   the air-tightness. Note that bending is conducted with care, since the worse air tightness
   impedes the normal operation of TCO. Holders or tools used during lead forming must not
   grasp the body, but lead wire. Doing so can protect the damage the body of TCO.

ii) Forming lead wire other than sealed lead
    Bend at least 4mm away from TCO body since excessive force to the body causes the
    deformation of TCO case.

iii) Forming of lead wire using the jig or radio-pincer keep away from cutting, denting,
    crack, etc.

i) Be careful to be free from damage, burn, nick, crack or overheating at TCO seal or body.
   If there are such damage as above, do not use.   

ii) Experimental assembly trials should be made to check the damage of lead wire, seal or
    TCO body.

iii) When connecting wire to TCO, it is recommended that splice or terminal shall be used.
    The material of splice or terminal should be corrosion resistant.

iv) When securing the splice or terminal to TCO, be careful not to damage to TCO body.
    The material of splice or terminal should be low resistant. Be careful not cause excessive
    overheating due to worse connection method.

    It should be noted that the connection wire shall be flexible stranded wire.
    If use the solid wire, use the bending process. 

The following points should be noted if soldering is conducted to connect TCO lead.

 i) Conduct soldering work on lead far from the TCO body if possible.

ii) Be careful to minimize the heat transfer to TCO body. When the mean to prevent the heat
    transfer is not provided, TCO seal or body may be damaged and broken-down.

iii) To shorten the working time, employ pre-soldering process at the intended soldering
     area.

iv) Conduct the soldering work isolating process by securing the lead nearest at the body
    by pincer.
 
v) Soldering Method to prevent heat.

vi) Mechanical security must not depend on solder alone. 
 

Electric current must not pass through inner electric contact or case of TCO when welding.
The reason is why the passing through of over current damages the TCO element or case.

It is not suitable to use in the location being in water, organic material, sulfurous acid gas,
etc.

 i) Tensile strength of lead
    Pull force shall not be over 2kg and push force shall not be over 0.5 kg.

ii) Strength of Case
    Applying the excessive force to tie the case body causes the deformation and worse
    normal operation of TCO. Since this may cause no-operation of fuse, be assure to
    avoid the excessive tying force.