Precision Zone specializes in Yaskawa product repairs servicing a wide range of AC Servo series such as Yaskawa SGDC Sigma 1 Series Servopack.

The Sigma 1 Series originally launched in 1993 by Yaskawa. The need for devices that can provide more precise and quicker motion at high speeds compared to other servo systems on the market resulted in Sigma 1 Series launch. Rapid progress in the automation and information technologies results in a growing need for more advanced motion control equipment. One feature of these high end drives is the use of SigmaWin Plus Software or a digital operator that can be plugged into the front of these drives to change parameters, check alarms, or monitor the dive while in operation.

When assessing the functionality of a drive, our engineering team typically conducts a four-step check:

• Visual Overview Check
• Static Test
• Checks Under Power
• Alarm Codes Verification

This overview is Precision Zone’s basic troubleshooting process. Once our repair team starts on the job we use specialized, customized test fixtures, Huntron tracker, signal generator, oscilloscope, milli and mega ohm meters and other necessary tools to assure quality repair. Most importantly, every repair is fully tested in custom-built simulators under load to replicate real-life working environment. Precision Zone goes as far as using heat chamber and overnight dynamic testing to guarantee performance of the repaired product when it comes back to the customer.

REPAIR PROCESS FOR SGDC SERIES SERVOPACKS

Visual Overview Check

When conducting a visual check, the technician inspects the drive for any mechanical damage to the drive and print circuit boards. Then the team proceeds to verify connections are tight and correct inside the drive and there are no loose screws, wires or particles. Additionally, we look for any burn marks anywhere on the components or chassis. During the visual inspection technical team notes excessive dirt on cooling components and records clogged heatsink.

Static Test Basic

Precision Zone repair technicians use digital multimeter with diode testing capabilities and resistance measurement to conduct a static test. In the instance of Diode testing, our team is looking to check input and output modules.

Input Modules Testing

Multimeter Positive Lead	Multimeter Negative Lead	Diode Check
Negative Capacitor Terminal	R S T	Approximately 0.2-1.0 V
R S T	Positive Capacitor Terminal	Approximately 0.2-1.0 V

Output Modules Testing

Multimeter Positive Lead	Multimeter Negative Lead	Diode Check
Negative Capacitor Terminal	U V W	Approximately 0.2-1.0 V
U V W	Positive Capacitor Terminal	Approximately 0.2-1.0 V

We verify capacitor value using capacitor meter and examine functionality of circuit breakers and contactors in the drive.

The last step in a static test process is checking the Regen Resistor. The technicians measure the resistance between Y3 and Y4. Resistance output results will vary depending on the size of the drive, but should not be shorted.

Alarm Codes Troubleshooting

The alarms on the SGDC Sigma 1 Series servopack must be viewed through a digital operator that plugs into the front of the drive. The codes displayed are:

Alarm Code	Code Type	Alarm Type	Cause
A.02	Parameter Breakdown	Soft Alarms	Incorrect parameters or corrupted data
A.04	Parameter Setting Error	Soft Alarms	Incorrect parameters or corrupted data
CPF00 and CPF01	Digital Operator Transmission Error	Control Circuit Alarms	Control circuit drive problem
A.30	Regeneration Error Detected	Braking Circuitry Alarms	Regen circuit failure or faulty regen resistor
A.40	Overvoltage	Braking Circuitry Alarms	Regen circuit failure or faulty regen resistor
A.40	Overvoltage	Braking Circuitry Alarms	Regen circuit failure or faulty regen resistor
A.F1	Power Line Open Phase	Power Alarm	Incoming voltage problem
A.F3	Power Loss Error	Power Alarm	Incoming voltage problem
A.10	Overcurrent or Heat Sink Overheated	Motor & Encoder Alarm	Low ground insulation
A.51	Overspeed	Motor & Encoder Alarm	Incorrect motor connection
A.71	Overload: High Load	Motor & Encoder Alarm	Load problems
A.72	Overload: Low Load	Motor & Encoder Alarm	Load problems
A.A1	Heatsink overheated	Motor & Encoder Alarm	Load problems
A.80	Absolute Encoder Error	Motor & Encoder Alarm	Cables and connections issues
A.81	Absolute Encoder Backup Error	Motor & Encoder Alarm	Cables and connections issues
A.82	Absolute Encoder Checksum Error	Motor & Encoder Alarm	Cables and connections issues
A.84	Absolute Encoder Data Error	Motor & Encoder Alarm	Cables and connections issues
A.C9	Encoder Communications Error	Motor & Encoder Alarm	Cables and connections issues
A.CA	Encoder Parameter Error	Motor & Encoder Alarm	Cables and connections issues
A.00	Absolute Data Error	Motor & Encoder Alarm	Cables and connections issues

Alarm Y.Pr - Indicates a parameter error which could occur if data has become corrupted or incorrect parameters were loaded. If reloading parameters doesn’t correct this issue there is likely a problem with the drive.

2 MCCB Trip - Can occur during shipping or if something has shorted out in the drive. So if you just received this drive please make sure the breaker is no tripped, or if it was running, find the source of the short before resetting this breaker.

The majority of these alarms can be triggered if there is a fault in the control circuit.