Applies To: Baths, Micro Baths, and Dry Well Calibrators
Failure of the Triac can cause heating circuits to behave abnormally.
To determine if a Triac is operating correctly, do the following:
- Disconnect the instrument from its power source.
- Locate the Triac.
- Mark and then disconnect the lead wires connected to the Triac.
- Using an Ohmmeter check the terminal-to-terminal resistance as shown in Table 1.
- If any of the resistance values are outside of the guidelines shown in Table 1, the Triac should be replaced.
- If the resistance values are within the guidelines or after the Triac has been replaced, reconnect the lead wires to their correct terminals.
Table 1: General Resistance Guideline
40Ω < G to MT1 < 100 Ω
MT1 to MT2 > 20 MΩ
MT2 to G > 20 MΩ
NOTE: Resistances listed in Table 1 are not absolute and should only be used as a troubleshooting guideline. Reversing polarity of the measurement will change measured results. Measure + to -, for example positive lead on G and negative lead on MT1.
Q4025P / Q6025P BTA25-600BW