REGEN - Troubleshooting Guide

Introduction

The REGEN load 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.

REGEN load assemblies 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 Table

Symptom	Possible Cause	Corrective Action
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.
	The Vector drive is defective.	Chek the REGEN circuit at the vector drive.
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.
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.
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.

Regen Inspection

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.
Note: A reading in the range of Megaohms from leg to chassis is not an indication of a shorted unit.

If the REGEN loads are within specification, there can be a problem with the vector drive refer to: Vector Drive - Troubleshooting Guide to troubleshoot the vector drive.

Short Circuit Inspection

Corrective Action:

Check the REGEN circuit at the vector drive.

Go to to: Vector Drive - Troubleshooting Guide to troubleshoot the vector drive.

Incoming AC Voltage Inspection

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.

Servo and 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.

Review the Part Program

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.