4-11. High Frequency Controls

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2

Y Place High Frequency switch in Off position before using the shielded metal arc welding (SMAW) process.

1 High Frequency Switch

START – (Up position) provides HF for arc starting only. High frequency turns on to help start arc when out- put is enabled. High frequency turns off when arc is started, and turns on whenever arc is broken to help restart arc.

Application:

HF Start is used when the DCEN GTAW process is required.

OFF – provides no HF. Use OFF for SMAW (stick electrode) welding.

CONTINUOUS – (Down position) provides HF continuously through- out the weld.

Application:

HF Continuous is used when the AC GTAW process is required.

2High Frequency Intensity Control

Use control to change amount of HF energy used to start and main- tain the arc. Set as low as practical to prevent interfering with electronic equipment.

4-12. Preflow Time Control (Optional)

1 Preflow Time Control

Use control to set the length of time (0–15 seconds) that gas flows be- fore an arc is started.

Application:

Preflow is used to purge the imme- diate weld area of atmosphere. Pre- flow also aids in consistent arc starting.

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TM-353 Page 19

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Miller Electric TM-353E manual High Frequency Controls, Preflow Time Control Optional