Okuma BL-D Servo Drive Repair Specialists

Okuma BL-D50A Servo Drive

At Precision Zone, we specialize in Okuma product repairs which include a wide range of AC Servo Drives. One of the many types of servos we service is the Okuma BL-D servo.

Okuma’s BL-D servo amplifiers are the precursor to the BL-D AC servo drives. Ranging from 15A offerings up to 150A of output, these drives service a wide range of settings. A revision of this drive shortly after its inception leads to two distinct variations of the same drive. The BL-D*A has 1 control board whereas the BL-D*D has 2 control boards. Both drives have distinct DIP switch settings making these drives programmable.

The drive is designed to be compact and efficient while allowing for easy to see alarm and status monitoring. Using check pins on the main servo control board, motor speed and torque can be check as voltage outputs.

When assessing the functionality of a Okuma BL-D Servo Drives, our highly skilled repair team of engineers and technicians employs a basic four step troubleshooting process:

  • 1. Visual Overview
  • 2. Static Test
  • 3. Checks Under Power
  • 4. Alarm Codes Verification

This overview is Precision Zone’s basic troubleshooting process. Once our repair team starts on the job, we use specialized and customized testing fixtures, Huntron trackers, signal generators, oscilloscopes, milli and mega ohm meters, as well as any other necessary tools we have available to assure quality repair work. Most importantly, every repair is fully tested in our custom-built simulators under load with a motor to replicate real-life working environment.

Precision Zone goes as far as using heating chambers and overnight dynamic testing, when applicable, to guarantee performance of the repaired product when it arrives back with the customer.

Repair Process for Okuma BL-D Servos

Visual Overview

When conducting a visual check, the technician inspects the drive for any mechanical damage to the drive itself and any printed circuit boards. The technician then proceeds to verify connections are tight and correct inside the drive and there are no loose screws, wires or debris. Additionally, the unit is checked for any burn marks on the components, printed circuit boards or chassis. During the visual inspection, excessive dirt on cooling components is noted as well as the functionality of the heat sink.

Basic Static Check

Output Module Testing

Precision Zone repair technicians use digital multimeters with diode testing capabilities and also take resistance measurements to conduct a static test. For these units in particular, our team of technicians uses the diode function of the multimeter as well as huntron devices to check the output modules.

Positive Lead Negative Lead Reading
U Positive Bus Terminal 0.34V-0.40V
V Positive Bus Terminal 0.34V-0.40V
W Positive Bus Terminal 0.34V-0.40V
Negative Bus Terminal U 0.34V-0.40V
Negative Bus Terminal V 0.34V-0.40V
Negative Bus Terminal W 0.34V-0.40V

The capacitor values on the PCBs are verified and any relays, contactors or circuit breakers in the drive are examined to ensure proper functionality.

Checks Under Power and Alarm Code Verification

Upon successfully passing all visual and static checks, the drive is tested under power. Any reported alarm codes are verified and if no alarms are present or once the drive has been fully repaired, the drive is tested in our Okuma series simulator. Alarms and drive status can be verified on the LEDs directly on the servo pack.

On the BL-D servo packs, there are a handful of terminals for checking to ensure proper control voltage is distributed on the control boards. Our technicians check this under power to verify that proper ±5 and ±15 volts are present.

Common Alarms for the Mitsubishi FR-A024/FR-A044

Alarm Code Description Quick Checks
IOCM Overcurrent in the motor
  • Check wiring and ensure that all terminal screws are tight
  • Check the motor and motor cables for low winding resistance (meg the motor)
IOCS Overcurrent in the servo
  • Ensure that the inter-board connectors are securely inserted between the control and power boards.
  • Power off, disconnect motor and power up. If LED is still lit, repair of the servo drive is necessary
HV DC Voltage is abnormally high
  • Measure the incoming R-S-T voltages within a multimeter. Standard voltage levels reside between 170 and 222VAC
LV Under Voltage
  • Check incoming power with a multimeter
  • Check to make sure voltage input is at least 170VAC
  • Make sure circuit breaker is ON
  • Check all wiring
  • Statically check the protection diodes on IGBT
  • Check diode module

Precision Zone offers free technical support on any component that you may be having issues with. We understand that when your machine goes down, your business stops. That is why our number one goal is to provide you with the best service possible so that you can get back up and running immediately. For more information on troubleshooting the Okuma BL-D AC Servo Drives or for any other machine related issues, please contact us via phone or email for further assistance.

Precision Zone Repair Benefits for Okuma BL-D AC Servo Drives

  • Free evaluation by expert technicians include:
  • Visual Inspection
  • Static Check
  • Power Tests
  • Free Job Estimate
  • 12 month warranty on our parts and labor
  • Flat Price
  • Exchange Options
  • Rush Service Options

Contact Us To Start Your Repair Today!

Recently Repaired Products

Okuma BL-D50A image BL-D50A is an
Drives-AC Servo manufactured by Okuma
Discovered issues: Bad Gate Section/Board, Bad Output Transistors/SCRs
Drive Type: AC Servo Drive
Motor Current Rating: 50A
Option: A

Okuma BL-D75A image BL-D75A is an
Drives-AC Servo manufactured by Okuma
Discovered issues: Bad Magnetic Contactor, Relay, Multiple signs of previous repair, Passed Testing - Highly Recommend Recondition
Drive Type: AC Servo Drive
Motor Current Rating: 75A
Option: A

Okuma BL-D30A image BL-D30A is an
Drives-AC Servo manufactured by Okuma
Discovered issues: Multiple signs of previous repair, No Display
Drive Type: AC Servo Drive
Motor Current Rating: 30A
Option: A

Okuma BL-D50D image BL-D50D is an
Drives-AC Servo manufactured by Okuma
Discovered issues: Bad Gate Section/Board, Bad Magnetic Contactor, Relay
Drive Type: AC Servo Drive
Motor Current Rating: 50A
Option: D

Okuma BL-D30D image BL-D30D is an
Drives-AC Servo manufactured by Okuma
Discovered issues: Bad Control Section/Board, Bad Magnetic Contactor, Relay, May Require Board Replacement
Drive Type: AC Servo Drive
Motor Current Rating: 30A
Option: D

Okuma BL-D150A image BL-D150A is an
Drives-AC Servo manufactured by Okuma
Discovered issues: Bad Output Transistors/SCRs, Leaky Capacitors (Open, Corroded Traces)
Drive Type: AC Servo Drive
Motor Current Rating: 150A
Option: A