560

Check parameter 4012 bit 0 (brake confirmation signal polarity) and verify it matches your hardware configuration. Also check parameter 4013 for brake application/release time settings.

With spindle stopped and LOTO applied, inspect the brake confirmation switch (usually mounted on spindle motor brake housing) for proper gap (typically 1-2mm) and secure mounting.

LOCK OUT/TAG OUT required - ensure spindle cannot rotate

Using a multimeter in continuity mode, verify the brake confirmation switch changes state when the brake is manually engaged/released. Check wiring from switch to spindle amplifier connector for continuity and proper termination.

In the spindle amplifier diagnostics screen, monitor the brake confirmation signal (BRK or BRKR) while commanding spindle start/stop to verify signal timing and state changes correspond to brake action.

With LOTO applied, remove spindle motor brake cover and visually inspect brake disc and pads for excessive wear, contamination (oil, coolant), or damage. Check that brake pad thickness meets manufacturer minimum specifications (typically 3-5mm minimum).

LOCK OUT/TAG OUT required - high voltage present at motor connections

Check brake coil resistance with multimeter (typically 50-200 ohms depending on model). Compare to motor nameplate or manual specifications. Open circuit or very low resistance indicates coil failure.

Manually verify the brake armature moves freely by pressing against the spring tension. It should move smoothly without binding. Check for rust, debris, or damaged guide pins preventing movement.

Measure the air gap between brake disc and armature when released (coil energized). Typical specification is 0.2-0.5mm. If out of specification, adjust per motor manual or replace worn components.

Ensure brake power is disconnected before adjusting gap

Check the dedicated brake fuse or circuit breaker in the spindle drive cabinet (consult electrical schematic for location - typically labeled SP-BRK or similar). Replace if blown and investigate cause.

Disconnect main power before accessing drive cabinet

At the spindle amplifier, measure DC voltage at the brake output terminals during spindle start command (brake should release). Typical voltage is 90-180VDC or 24VDC depending on system. No voltage indicates amplifier or relay failure.

HIGH VOLTAGE PRESENT - use insulated test leads and PPE

Inspect all wiring and connectors between spindle amplifier and motor brake coil for damage, burnt terminals, or loose connections. Pay special attention to connector pins at both amplifier (JA7/JA8 on many models) and motor terminal box.

If equipped with a separate brake relay/contactor, verify it operates correctly by listening for audible click during spindle command and checking contact closure with multimeter. Replace relay if defective.