Dear CNC Expert,
I have a machine Fanuc 18MC. Initially the machine shows an error; AL-27 Position coder signal disconnection.
So, we have bought a new encoder and change old one.
Now motor rotates for few seconds.
While I run program with cycle start then for few seconds Spindle rotates. But no speed show on Display or gauge rather within few seconds current showing at ampere gauge is increased very quickly. Current gauge touching 100% current, then 125% current and finally 150% current within few seconds and motor stop and new alarm came: 751 Spindle-1 Alarm detect (AL-31)

Attachment 331970

So, I have check following things.

1. If I rotate my spindle through hand then no RPM shows on display or gauge.
2. I have checked encoder is getting 5 voltages.
3. I have checked encoder to servo amplifier cable is ok.

Is there anyway to bypass motor speed check from parameter.

Can anyone help how can I solve this problem?