How to test the functioning temperature when conducting IQC inspection?
If you have a silicon oil bath for testing TCO’s functioning temperature. Please pay attention to below tips:
1. The current passing TCO is less than 10mA.
2. Put the TCO into the silicon oil bath at a point of Tf-12℃.(For example, TCO of A4-F series should be put into the silicon oil bath when the temperature reach 118℃). You’d better keep the temperature constant for about 30 minutes.
3. Put the temperature probe into the silicon oil bath together with the TCO. Then the temperature of silicon oil bath rise at a rate of 0.5-1℃ per minute till the TCO fuse-off.
4.The probe should be attached to the TCO as close as possible.
You could use a constant temperature oven with the blowing device to do the test if you don’t have a silicon oil bath. When using a constant temperature oven Please pay attention to:
a. Put the TCO into the silicon oil bath at a point of Tf-12℃. You’d better keep the temperature constant for about 30 minutes.
b. To ensure the accuracy of temperature inside of the oven, you’d better put the TCO into the oven together with a probe.
c. The temperature of silicon oil bath rise at a rate of 0.5-1℃ per minute till the TCO fuse-off.The rate of heating up can not exceed 1℃ per minute after putting in the TCO
How to install TCO to achieve the optimal performance?
There are two ways for TCO to sense the temperature.
1. The TCO body needs to be put close to the heat source. TCO feels the temperature through the body. As the body of TCO (alloy type)has no direct contact with the thermal alloy, it takes more time when the heat from the body transfer to the thermal alloy. The heat transfer rate is slow in the kind of installation. The fusing off action would come in with delay.
2. The lead wires of TCO need to be put close to the heat source or to be connected with the heat source directly. TCO feel the temperature through the lead wires. As the lead wires are connected to the thermal alloy directly, thermal alloy could feel the heat source once the lead wires feel it. Because the lead wires are no insulated, it is suggested that customers to put good heat transfer and good withstand voltage bushing outside of the them.
PS: TCO is not allowed to be suspended inside of the equipment.