Haas Automation Next Generation Control (NGC) alarm 160: LOW INCOMING AC LINE VOLTAGE
Alarm 160 LOW INCOMING AC LINE VOLTAGE on a Haas NGC means the incoming voltage to the machine is less than 80% of the expected value. Haas’s action is to check the supply voltage and the transformer taps.
Diagnose this with AI
Try Free CNC Alarm Diagnostic Upload a keypad photo, the fault history or a parameter export from your Haas Automation Next Generation Control (NGC). InduQT compares the evidence and suggests the next useful checks.
When it happens
- At power-up
- When the spindle or axes draw heavy current
- During plant supply dips
Likely causes and checks
1Transformer taps set for a higher supply than the shop provides
- Points to it
- Alarm since installation or after the machine was moved; supply measures normal for the shop.
- Check
- Have a qualified electrician compare the transformer tap setting with the measured supply, per the machine’s installation documentation.
2Low or sagging plant supply
- Points to it
- Alarm coincides with other large loads starting or with spindle acceleration.
- Check
- Have the supply measured at the machine disconnect under load and compare with the machine’s rating.
3Supply wiring or connection problem
- Points to it
- Voltage drops on one phase or only under load.
- Check
- With the machine locked out, inspect the incoming terminals and disconnect for loose or overheated connections.
Telling it apart
- Alarm 119 INPUT AC LINE OVERVOLTAGE is the opposite: supply more than 20% above what is expected; 177 OVERVOLTAGE SHUTDOWN shuts the machine down for high voltage.
- Alarm 175 GROUND FAULT DETECTED and 9804 240VAC GROUND FAULT point to insulation faults, not supply level.
Evidence to collect
- Measured supply voltage at the machine, idle and under load
- Transformer tap setting
- Whether other plant loads switch at the same time
Work on fuel trains, burners, pressure vessels and electrical equipment must be done by qualified personnel following the manufacturer’s documentation and local codes. Never bypass a safety device or interlock.