Yaskawa V7 General-Purpose Inverter Repair Experts

Here at Precision Zone, one of our specialties is the repair services of Yaskawainverter units. One series that we often work on is the V7 series.

The V7 is a legacy Yaskawa inverter designed as a low cost, high performance drive. The compact unit is operable in V/f or open loop vector mode. This series can provide higher torque at lower speeds and has size offerings from 1/8th HP to 10 HP. Available in either 230V input or 460V inputs, the V7 was designed for pumps, fans, blowers and packaging equipment.

When assessing the functionality of a Yaskawa General-Purpose Inverter, our expert repair team of engineers and technicians conducts a four-step check:

    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 megaohm 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 Yaskawa V7 Series General-Purpose Drive Units

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 (PCB). 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, PCBs 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

Input Module Testing

The input modules on these units can be tested by use of a digital multimeter with diode checking capabilities. Upon removing the cover, all of these terminals can be located along the terminal strip found within the unit.

Positive Lead Negative Lead Reading
L1 + Terminal 0.3V-0.7V
L2 + Terminal 0.3V-0.7V
L3 + Terminal 0.3V-0.7V
- Terminal (Minus) L1 0.3V-0.7V
- Terminal (Minus) L2 0.3V-0.7V
- Terminal (Minus) L3 0.3V-0.7V

Output Module Testing

Using the same type of test as above, the output modules can be checked as well. Our technicians are also equipped with huntron devices further verify their integrity.

Positive Lead Negative Lead Reading
T1 + Terminal 0.3V-0.7V
T2 + Terminal 0.3V-0.7V
T3 + Terminal 0.3V-0.7V
- Terminal (Minus) T1 0.3V-0.7V
- Terminal (Minus) T2 0.3V-0.7V
- Terminal (Minus) T3 0.3V-0.7V

Common Alarms for the Yaskawa V7 General-Purpose Inverter Unit

Alarm Code Description Checks
Uu Main Circuit Undervoltage
  • Check power supply voltage
  • Check main circuit power supply wiring
  • Check that terminal screws are tightened completely and there are no loose wires
oH Overheat Alarm
  • Check the operating conditions of the drive – ensure that the drive is properly cooled
  • Check cooling fan. It should be working and not have dirt or debris blocking the air intake
oL1, oL2, oL3, oC Overload
Overcurrent
  • Check load size or V/f pattern setting
  • Check for any bindings on the affected axis
  • Meg motor and check motor winding insulation resistance
oV Overvoltage
  • Check power supply voltage
  • Increase deceleration time if alarm occurs during deceleration
  • Check main circuit power supply wiring
  • Check that terminal screws are tightened completely and there are no loose wires

A common display is “bb”. This is not an alarm but rather a temporary condition of the base power being blocked and output being shut off. Once drive is ready and has proper incoming power, this status should clear and allow the drive to sit in a stopped, but ready condition.

This list of checks for certain alarms is primarily a good starting point and if any further troubleshooting or technical support is needed feel free to contact us via phone or email to get in touch with our experienced tech support team.

Learn the benefit of repairing your Yaskawa inverter units with Precision Zone

  • Quick and Flexible Service
  • Fully Refurbished, not just repaired
  • Decades of Industry Experience
  • Superior Technology Knowledge and Support

Contact Us To Start Your Repair Today!


Recently Repaired Products

Yaskawa CIMR-V7AZB0P4 image CIMR-V7AZB0P4 is an
Inverter-General Purpose manufactured by Yaskawa
Discovered issues: Bad Input Diodes/SCRs, Leaky Capacitors (Open, Corroded Traces), Excessive Dirt/Debris, Bad Capacitor(s)
Drive Type: AC Inverter
Series: V7
Type: Digital operator provided (with potentiometer)
Specifications: European standard specifications (Omron)
Input Voltage: Single-phase 200VAC
Output Power: 0.4kW

Yaskawa CIMR-V7AU45P5 image CIMR-V7AU45P5 is an
Inverter-General Purpose manufactured by Yaskawa
Discovered issues: Bad Control Section/Board, Bad I/O
Drive Type: AC Inverter
Series: V7
Type: Digital operator provided (with potentiometer)
Specifications: UL sertification (U.S. specification)
Input Voltage: Three-phase 400VAC
Output Power: 5.5kW