Thermal Cutoffs (TCO)/Thermal-Links
Safety Precautions (Handling Precautions)
• Design Applications
447-XYP 1BF145-RC
1. Use TCO within their specified temperature and electrical ratings.
1) Use the TCO under an ambient temperature of not more than the maximum operating temperature specified in the individual specification.
Using the TCO under a higher temperature than the maximum operating temperature may cause premaure opening or opening delay.
• When the TCO is continuously used at a temperature close to the functioning temperature, the TCO may operate while being used.
• When the TCO is continuously used at the temperature higher than the maximum operation temperature, the TCO may be degraded and may not
operate normally at the specified temperature.
2) The holding temperature is defined as the highest temperature at which the TCO is activated continuously at the rated current for 168 hours.
The TCO can not be used over 168 hours exceeding the holding temperature.
3) Equipment should be designed so that its over shoot does not exceed the maximum temperature limit after the TCO operates.
4) If the TCO is activated by voltage higher than the rated voltage or current higher than the rated current, the TCO produces excessive heat,
resulting in premature opening. The arc generated at this condition of operation will result in an abnormality of appearance (crack on body)
and insufficient insulation.
• When TCO is operated in an abnormal mode while the rated voltage and/or the rated current being exceeded, it may not cut off the circuit.
5) Where transient overload is expected to be applied, repeat the tests under the worst conditions.
6) The TCO cannot be used as a current sensitive fuse.
2. To fully use the function of the TCO, a suitable TCO for each equipment application must be selected.
1) Tests should be repeated for the finished equipment to confirm that the TCO does operate as expected.
2) To improve thermal response of the TCO, put the main body of the TCO and the lead wires (terminals) as close to the heat source as possible
and the place where the TCO is evenly heated.
If the temperatures transferred to the main body and to the lead wires (terminals) are largely different from each other, improper operation can
be expected, causing arcing and deterioration of insulation.
3. Avoid application of excessive vibration and mechanical stress to the TCO. Otherwise, failure of the fusible alloy or lead wires, or damage to
the main body may result.
4. When sealing the TCO with resin, select a resin that does not corrode the seals or the lead wires (terminals). When sealing the overall TCO with
resin, test repeatedly to confirm normal operation of the TCO in the finished equipment.
5. Avoid dipping the equipment with the TCO into varnish or chemical or organic solvent and then drying it. The solvent or the varnish may corrode
the body and/or lead wires (terminals) of the TCO.
6. Do not use under the following environments.
1) In liquids such as water, oil, chemical and organic solvents.
2) Under direct sunlight and outdoor and dusty atmospheres.
3) In places where water condensation occurs.
Use in the following environments may affect the performance of the TCO; Verify performance and reliability before production use.
1) In places full of corrosive gases such as sea breeze, CI
2
, H
2
S, NH
3
, SO
2
and NO
2
.
2) In environments with high static electricity and/or strong electromagnetic waves.
Do not use the TCO in aerospace equipment, atomic energy equipment, military weapons, life saving equipment, etc.
7. Forming and Cutting
1) Lead wires (terminals) are to be bent or cut at least 3mm away from the TCO seals to avoid damaging the TCO (axial / radial type) or body
(thin type). The TCO seals (axial / radial type) shall not be grasped with any tools or holders. Terminals of thin typr TCO are to be grasped
before they are bent. (See Fig. 1)
2) The lead wires and terminals shall not be nicked, fractured, or bumed. The body and/or seals must not be damaged, burned, or overheated.
3) It is recommended that experimental assembly trails should be done so that it can be verified that manufacturing procedures will not exceed
the maximum tested “pull” and “push” forces of 20 N (MT Series: 10 N, MS Series: 5 N) and 5 N respectively on the lead wires (terminals),
or induce excessive twisting or the like.
Bending
Cutting
>3mm
>3mm
>3mm
>3mm
>3mm
>3mm
XICON PASSIVE COMPONENTS • (800) 628-0544
3
Thermal Cutoffs (TCO)/Thermal-Links
447-XYP 1BF145-RC
8. Soldering, Welding, Encapsulation
1) Lead wires are to be soldered with the standard conditions shown in Table 1. Excessive soldering heat and soldering time may cause damage
to a TCO. If higher temperature, longer time or shorter lead length exist rather than the conditions of Table 1, it is recommended to run tests for
finding the soldering conditions that do not damage the TCO. Also, use of tools such as pliers are recommended to dissipate the soldering heat
by grasping lead wires between the TCO body and soldering point.
2) Avoid preheating and gradual cooling as far as possible. However, if preheating and gradual cooling is done, set the process conditions after
confirming that the TCO is not affected by these procedures.
3) Do not use reflow soldering.
4) Thin type (MT, MS Series) is not to be soldered.
5) If water or solvent is used for cleaning flux after soldering, check and confirm the reliability of the agent.
6) Lead wires are to be clamped at least 3mm away from the seals. Improper connections may cause damage to the seals or other parts and may
result in nuisance tripping of the devices due to the generation of excessive heat at a faulty high resistance junction.
7) Set the conditions for welding and encapsulation only after checking contact resistance and connection strength.
8) When resoldering or rewelding, cool the TCo under room conditions.
9) When the TCO is heated by soldering or welding, be careful not to pull, push, or twist the TCO lead wires.
Temperature of Soldering: 300°C
Lead
Length ( )
25mm
20mm
15mm
10mm
N082, N088
N098, N109
N110
N124, N126
N135, N143
N163, N183
F102
F115, F130
F133, F139
F168
Type No.
Time: 3s
•
H102, H115
H130, H133
H139
H168
Soldering Point
E102, E115
E130, E133
E139
9. The use of sufficiently flexible, appropriate free length and proper size wire should be used for splice connection. Connection including connectors
used for splicing shall be of the low resistance type, and they shall be made mechanically secure.
10. Where the lead wires of the TCO is tied with string, put them a least 10mm apart from the seals of the main body of the TCO.
11. Quality control notes:
1) Measurement of resistance between lead wires (terminals) and checking of the internal status with X-rays are effective means to confirm the
status of the TCO on delivery and after mounting in the equipment.
2) It is not necessary to confirm normal operation of the TCO with trial units and with a prototype equipment lot set at normal and abnormal
conditions.
12. Storage Method
1) Store the TCO in packing cases or in polyethylene bags within the temperature range -10°C to +40°C and RH of 30% to 75%. Store them at
a location where no rapid changes of temperature or humidity or no direct sunlight is applied. The location must also be free from vibration
and shock.
2) Avoid storage in places containing corrosive gases such as sea breeze, CI
2
, H, S
2
, NH
3
, SO
2
and NO
2
.
3) The period of guarantee for performance such as solderability is for 1 year after our delivery; and this condition applies only in the case
where the storage method specified in above has been followed.
13. Do not repair a TCO. Replace it with a new part.
Note: This specification sheet shows the quality and performance of a unit component. For quality assurance, contact us with your requirements.
Before using, be sure to evaluate and verify the product after mounting it in your product.
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4
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