What causes Haas alarm 87?

Dull or improperly sized cutting tool causing excessive cutting forces that overload spindle motor beyond rated capacity. Spindle belt tension too tight, causing excessive mechanical drag and increased current draw even during no-load conditions. Failed spindle motor bearings creating mechanical binding and friction that increases current requirement during rotation. Contamination or crash damage to spindle taper or drawbar mechanism causing binding during tool rotation or tool pull stud dragging. Incorrect spindle load parameter settings (Setting 12 or 13) set too low for the application, causing nuisance tripping on normal loads.

How do I fix Haas alarm 87?

1. Step 1: Review spindle load meter on screen during the operation that caused alarm to determine if overload was gradual or instantaneous 2. Step 2: Manually rotate spindle by hand with power off to check for mechanical binding, rough bearings, or abnormal drag in rotation 3. Step 3: Check spindle belt tension per Haas specification using belt tension gauge, adjust if too tight or too loose 4. Step 4: Run spindle at various speeds with no tool and no load while monitoring spindle load on Diagnostics page to establish baseline current draw 5. Step 5: Review and verify Settings 12 (Spindle Motor Overload) and 13 (Spindle Motor Rated Current) match machine specifications in service manual 6. Step 6: If mechanical components check good and settings are correct, monitor spindle drive DC bus voltage and current with meter during fault to identify drive module or motor winding issues

axismd.ai

Haas Controller

Spindle · Intermediate · 30-90 minutes

Alarm 87

HAAS Alarm 87 - Spindle Overload Current Detected

Alarm 87 fires when the spindle motor current exceeds the overload threshold set in Parameter 71 (SPINDLE OVERLOAD CURRENT). The NGC control monitors actual spindle current through the spindle drive and triggers this alarm to protect the spindle motor from damage due to excessive load conditions.

HaasSpindleIntermediate30-90 minutes

87

HAAS Alarm 87 - Spindle Overload Current Detected

Spindle Overload Current Detected

Root Cause Summary

Alarm 87 fires when the spindle motor current exceeds the overload threshold set in Parameter 71 (SPINDLE OVERLOAD CURRENT). The NGC control monitors actual spindle current through the spindle drive and triggers this alarm to protect the spindle motor from damage due to excessive load conditions.

Safety

Never attempt to force spindle rotation when overload alarm is active as motor damage may occur
Allow adequate cooling time before re-running program to prevent thermal shutdown
Ensure all machine guards are in place before resuming spindle operation

Causes and Fixes

1
Check Tool Condition
Inspect cutting tool for wear, chipping, or damage. Replace if cutting edges are dull or damaged.
Use a magnifying glass or tool scope to check for micro-chipping on carbide tools
2
Verify Tool Parameters
Check Tool Offset page for correct tool geometry and ensure proper speeds/feeds for material being cut.
Never exceed manufacturer's recommended cutting parameters
3
Test with New Tool
Install a new, sharp tool of the same type and re-run the program at reduced feed rate to verify alarm clears.

DIY Feasiblehigh confidence

Call a technician if:

·Alarm occurs without cutting load
·Parameter changes don't resolve issue
·Motor insulation test fails
·Unusual spindle noises or vibration

Prevention

Monitor spindle load percentage during cutting
Replace tools before they become excessively worn
Use proper speeds and feeds for material
Perform regular spindle bearing maintenance

Common Mistakes

Ignoring gradual increase in spindle load over time
Setting Parameter 71 too high to avoid alarms
Continuing to run with worn tools
Not monitoring spindle current during setup

Related Alarms

86 88 91 92

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.