Regen - How it Works and Troubleshooting Guide

How it Works

Haas Automation machines use a method called "Dynamic Braking" to decelerate (slow down) servo and spindle motors. Dynamic braking is one of the simplest, most common and reliable methods of dealing with the energy generated during braking. The REGEN load is a very important part of the regeneration system since it is the component responsible for dissipating the energy generated during deceleration. The REGEN converts the high energy load into heat with the use of resistors.

When the motors velocity decreases, the motor acts as a generator. This converts the mechanical energy from the motor shaft into electrical energy. The electrical energy from the motor during deceleration is transferred back to the vector drive. This energy is seen by the vector drive as extra voltage in the DC Bus. The vector drive monitors the DC Bus and as the voltage increases to 400 VDC, the regeneration load section turns on and releases the energy through the REGEN load resistors. When the voltage drops to 380 VDC, the vector drive shuts off the regeneration load. This process repeats until the motor is at a complete stop.

 

 

 

 

There are five versions of the REGEN load assembly currently used in machines:

Part Number Description Nominal Resistance (Ohms) Machine
93-32-5017 REGEN Assembly OM 22 OM
93-32-0041B REGEN Assembly Mini Mill 11 MM, TM, TL
93-32-0043A REGEN Assembly 7.5 Machines with a 20 HP Vector Drive
93-32-0042A REGEN Assembly 5.6 Machines with a 40 HP Vector Drive
93-32-0194 REGEN Assembly 55HP 5.6 Machines with a 60 HP Vector Drive

 

 

Symptom Possible Cause Corrective Action Section
Alarm 123 SPINDLE DRIVE FAULT,

Alarm 119 OVERVOLTAGE,

Alarm 292 HIGH VOLTAGE POWER SUPPLY FAULT,

Alarm 650 DC BUS OVERVOLTAGE,

Alarm 444 REGEN REMAINED ON TOO LONG

Alarm 237 SPINDLE FOLLOWING ERROR,

Alarm 647 REGEN LOAD SHORTED
The REGEN load is open or has a short circuit. Measure the REGEN resistors. 1
The Vector drive is defective. Chek the REGEN circuit at the vector drive. 2
The REGEN elements glow red/overheat when the machine is idle and is in EMERGENCY STOP

or Alarm 444 REGEN REMAINED ON TOO LONG

There is a problem with the incoming AC power. Measure the incoming AC Power. 3
The REGEN elements glow red/overheat when the machine is idle, and the servos are enabled. The symptom disappears when the EMERGENCY STOP is pressed,

or Alarm 444 REGEN REMAINED ON TOO LONG

There is a short on any of the servo motors and/or spindle motor. Measure the resistance to the servo motors and the spindle motor. 4
Lathes: The REGEN elements glow red/overheat when the machine runs constant surface speed G96 or when the spindle decelerates after a new chuck or part was installed. The deceleration/acceleration cycles are too aggressive. Review and reduce the spindle speed of acceleration/deceleration cycles. 5

Section 1

Symptom: Alarm 123 SPINDLE DRIVE FAULT, Alarm 119 OVERVOLTAGE, Alarm 292 HIGH VOLTAGE POWER SUPPLY FAULT, Alarm 650 DC BUS OVERVOLTAGE, or Alarm 444 REGEN REMAINED ON TOO LONG, Alarm 237 SPINDLE FOLLOWING ERROR, or Alarm 647 REGEN LOAD SHORTED.

Possible Cause: The REGEN load is open or has a short circuit.

Corrective Action:

Disconnect the REGEN load leads from the vector drive at terminals 1 and 2. Measure the resistance across the leads. The reading must be as follows:

  • 2-resistor box: between 9.5 and 12.5 ohms.
  • 3-resistor box: between 6.3 and 8.3 ohms ohms. (As shown in the illustration.)
  • 4-resistor box: between 4.6 and 6.6 ohms.

Measure each lead to the ground to make sure the REGEN does not have a short circuit.

If the REGEN loads are within specification, there can be a problem with the vector drive refer to section 2.

Section 2

Symptom: Alarm 123 SPINDLE DRIVE FAULT, Alarm 119 OVERVOLTAGE, Alarm 292 HIGH VOLTAGE POWER SUPPLY FAULT, Alarm 650 DC BUS OVERVOLTAGE, or Alarm 444 REGEN REMAINED ON TOO LONG, Alarm 237 SPINDLE FOLLOWING ERROR, or Alarm 647 REGEN LOAD SHORTED.

Possible Cause: The Vector drive is defective.

Corrective Action:

Check the REGEN circuit at the vector drive.

Go to to diy.haascnc.com to troubleshoot the vector drive.

Section 3

Symptom: The REGEN elements glow red/overheat when the machine is idle and is in EMERGENCY STOP or Alarm 444 REGEN REMAINED ON TOO LONG.

Possible Cause: There is a problem with the incoming AC power.

Corrective Action:

Measure the incoming voltage to the machine at the main incoming breaker in the control. Make sure that the incoming voltage is within the range of the transformer’s tap [1]. Move the lines to the correct tap if needed.

Section 4

Symptom: The REGEN elements glow red/overheat when the machine is idle, and the servos are enabled. The symptom disappears when the EMERGENCY STOP is pressed, or Alarm 444 REGEN REMAINED ON TOO LONG.

Possible Cause: There is a short on any of the servo motors and/or spindle motor.

Corrective Action:

Check each one of the servo motors and spindle motor. Measure the resistance from each one of the motor cables to chassis. Make sure that each one of the wires measures open to chassis. With the machine power off, disconnect all of the cables from each one of the amplifiers and measure the resistance of each terminal to the amplifier enclosure. Each terminal must measure open to the amplifier enclosure.

Section 5

Symptom: Lathes: The REGEN lelements glow red/overheat when the machine runs constant surface speed or when the spindle decelerates after a new chuck or part was installed.

Possible Cause: The deceleration/acceleration cycles are too aggressive.

Corrective Action:

Review and reduce the spindle speed of acceleration/deceleration cycles.

Make sure the deceleration/acceleration cycles are not too aggressive during G96 Constant Surface Speed cycles.

Add short dwell times between passes.

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.

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