How to Troubleshoot JUGAO Press Brake Electrical Malfunctions
Table of Contents
1. Identifying the Primary Triggers of JUGAO Press Brake Electrical Malfunctions
○ Power Supply Anomalies in CNC JUGAO Press Brakes
○ Malfunctions of Electrical Cabinet Components
2. A Systematic Troubleshooting Protocol for JUGAO Press Brake Electrical Issues
○ Step 1: Verify the Main Power Source and Emergency Stop Circuit
○ Step 2: Examine the Wiring Within the Electrical Cabinet
○ Step 3: Inspect the CNC Controller and HMI System
3. Diagnosing Electrical Faults in the Backgauge and Servo Motor
○ Alarm Triggers in the Backgauge Servo Driver
○ Motor Power Supply and Signal Wiring Defects
4. Resolving Malfunctions in Sensors and Safety Systems
○ Errors in Limit Switches and Position Sensors
○ Faults in Light Curtains and Safety Relays
5. Proactive Measures to Avoid Future Electrical Malfunctions in JUGAO Press Brakes
○ Routine Inspections of the Electrical Cabinet
○ Scheduled Preventive Maintenance Regimens
6. Frequently Asked Questions
7. Conclusion
Electrical malfunctions are the leading cause of unexpected downtime in JUGAO press brakes. When the machine’s controller displays error alarms or fails to start entirely, many operators jump to the conclusion that a severe, complex issue is at play. However, through hands-on industry experience, it’s clear that the vast majority of these electrical problems can be accurately identified and resolved with a structured, step-by-step troubleshooting process. This guide outlines the practical, field-tested methods for diagnosing electrical faults in CNC JUGAO press brakes. By systematically checking core components—including the power supply, wiring connections, control systems, and sensor arrays—you can swiftly pinpoint the root cause of the malfunction, restore stable machine operation, and minimize costly production downtime.
Identifying the Primary Triggers of JUGAO Press Brake Electrical Malfunctions

Electrical malfunctions in JUGAO press brakes are rarely random occurrences; they stem from a set of predictable, common causes. Establishing an understanding of these triggers before beginning any troubleshooting work streamlines the process and avoids unnecessary component checks and replacements.
Power Supply Anomalies in CNC JUGAO Press Brakes

The main power supply is always the first component to inspect when addressing a JUGAO press brake electrical malfunction. Unstable input voltage or a complete loss of power will render the entire machine inoperable, and this is a far more common issue than many operators realize.
Key warning signs of power supply problems include:
• The CNC controller fails to power on
• Sudden, unplanned machine shutdowns during operation
• Persistent, recurring electrical alarm codes on the HMI
To resolve these issues, verify that the main circuit breaker is fully engaged, use a multimeter to measure and confirm input voltage levels, and ensure the supplied power meets the exact voltage specifications of the JUGAO press brake.
Malfunctions of Electrical Cabinet Components

The electrical cabinet houses critical core components—contactors, relays, servo drives, and power modules—that are vital to the press brake’s operation. Over time, constant machine vibration and internal cabinet heat can cause these components to loosen, wear out, or sustain damage, leading to electrical faults.
Typical indicators of faulty electrical cabinet components are:
• A distinct burning odor emanating from the cabinet
• Abnormal, repetitive clicking sounds from relays
• Persistent alarm codes from the servo drive unit
Routine inspection of these components and regular tightening of terminal connections can prevent the vast majority of these avoidable malfunctions.
A Systematic Troubleshooting Protocol for JUGAO Press Brake Electrical Issues
When diagnosing electrical faults in JUGAO press brakes, a structured, step-by-step approach is the most effective strategy. This method eliminates guesswork, prevents unnecessary component replacement, and cuts down on overall machine downtime significantly.
Step 1: Verify the Main Power Source and Emergency Stop Circuit
The initial step in any troubleshooting process is to inspect the machine’s main power supply and emergency stop (E-stop) system, as a tripped safety circuit or power disruption is the root cause of many electrical malfunctions.
Confirm the following key details:
• The main power breaker is in the fully "on" position
• All E-stop buttons on the machine and control panel are fully released
• The safety relay is operating as designed and sending the correct signals
In countless field cases, JUGAO press brake electrical issues are traced back to a triggered safety circuit that operators initially overlook.
Step 2: Examine the Wiring Within the Electrical Cabinet
After confirming the power and E-stop circuit are functional, open the electrical cabinet and conduct a thorough inspection of all internal wiring and connections.
Focus on identifying these common issues:
• Loose terminal block connections
• Frayed, cut, or otherwise damaged wiring insulation
• Burned or corroded electrical connectors
Continuous vibration during normal press brake operation gradually loosens terminal connections over time, which can interrupt electrical signals to the machine’s motors, CNC controller, and other critical components.
Step 3: Inspect the CNC Controller and HMI System

Modern JUGAO press brakes depend on advanced CNC control systems—such as Delem, ESA, and Cybelec controllers—for all operational functions. If the HMI screen displays an alarm code, carefully document the code and cross-reference it with the machine’s official technical manual for targeted troubleshooting.
Common controller and HMI-related issues include:
• Software communication errors between the controller and machine components
• Axis drive alarm codes indicating motor or drive issues
• Complete system startup failures or frozen HMI screens
In most cases, a simple controller restart and a visual inspection of all communication cables (to check for loose connections or damage) will resolve these common issues.
Diagnosing Electrical Faults in the Backgauge and Servo Motor
The backgauge is a critical component for ensuring precise bending accuracy in JUGAO press brakes, and this system is prone to electrical malfunctions due to constant movement and signal transmission. Addressing backgauge and servo motor issues requires targeted inspection of the drive and wiring components.
Alarm Triggers in the Backgauge Servo Driver
If the backgauge ceases to move or loses its positional calibration, the servo driver is the primary component to inspect, as it regulates all motor movement and signal feedback.
Potential causes of servo driver alarms include:
• Interrupted encoder signal transmission due to wiring damage
• Servo motor overload protection engaging from excessive load
• Damaged communication cables between the driver and CNC controller
A visual inspection of encoder and communication cables (to check for fraying or loose connections) and a manual reset of the servo driver will restore normal backgauge operation in most instances.
Motor Power Supply and Signal Wiring Defects
A secondary critical step is inspecting the power wiring that supplies the backgauge servo motor. Loose power connections or damaged wiring insulation can interrupt both power delivery and signal feedback, leading to operational issues.
Common symptoms of wiring defects include:
• Complete failure of the backgauge axis to move
• Inconsistent positional accuracy during bending operations
• Persistent warning messages on the servo driver unit
Proper cable routing (to avoid pinching or wear) and secure, tightened terminal connections are simple yet effective measures to prevent these electrical faults.
Resolving Malfunctions in Sensors and Safety Systems
JUGAO press brakes rely on a network of sensors and safety devices to ensure both operational accuracy and operator safety. Malfunctions in these components trigger immediate electrical alarms and often cause the machine to shut down or refuse to start.
Errors in Limit Switches and Position Sensors

Limit switches and position sensors are designed to ensure all machine axes operate within pre-set, safe ranges. A malfunction in these sensors will prompt the CNC controller to lock axis movement as a safety precaution.
To troubleshoot sensor errors, conduct the following checks:
• Secure and undamaged wiring connections to the sensor
• Correct mechanical positioning of the sensor (no misalignment or physical obstruction)
• Functional indicator lights on the sensor (confirming power and signal transmission)
Replacing damaged or misaligned sensors is the primary solution for these issues, and this simple fix restores normal machine operation quickly.
Faults in Light Curtains and Safety Relays
Light curtains and safety relays are the first line of defense for operator safety, and any malfunction in these devices will trigger the machine’s safety interlock system, preventing startup or causing an immediate shutdown.
Test the following components to diagnose safety system faults:
• Proper alignment of the light curtain emitter and receiver (no obstructions)
• Operational status of the safety relay (confirming signal transmission)
• Electrical continuity of the entire emergency stop circuit
It is critical to ensure the safety system is fully functional before restarting production, as cutting corners on safety inspections poses severe risks to operators and the machine itself.
Proactive Measures to Avoid Future Electrical Malfunctions in JUGAO Press Brakes
Hands-on experience confirms that the vast majority of JUGAO press brake electrical malfunctions are preventable with consistent, proactive maintenance. Implementing a regular maintenance regimen eliminates avoidable faults and extends the lifespan of the machine’s electrical components.
Routine Inspections of the Electrical Cabinet
Monthly routine inspections of the electrical cabinet are a foundational preventive measure, and they focus on identifying early warning signs of potential issues before they escalate into full malfunctions.
Key inspection points include:
• Loose terminal block connections (tighten as needed)
• Excessive dust accumulation (clean to improve cooling)
• Overheating components (check for faulty cooling fans or blocked vents)
Keeping the electrical cabinet clean and free of debris significantly improves internal cooling, which prevents overheating and premature wear of sensitive electrical components.
Scheduled Preventive Maintenance Regimens
A formal, scheduled preventive maintenance program goes beyond routine cabinet inspections and addresses all electrical systems of the JUGAO press brake. This program should be tailored to the machine’s production volume (more frequent maintenance for high-production environments).
Core preventive maintenance tasks include:
• Inspecting all power cables and verifying proper grounding
• Checking servo drives and their cooling fans for wear or damage
• Functional testing of all safety circuits, sensors, and light curtains
These simple, regular maintenance steps drastically reduce the risk of unexpected electrical malfunctions and ensure consistent press brake operation.
Frequently Asked Questions
Q: What is the most common cause of electrical malfunctions in JUGAO press brakes?
A: The vast majority of issues stem from loose wiring connections, unstable power supply input, or faulty sensors. Consistent, routine inspections of these components are the best preventive measure.
Q: What is the fastest way to identify an electrical fault in a JUGAO press brake?
A: Start by reviewing the exact alarm code displayed on the CNC controller, inspecting the emergency stop circuit for tripped safety interlocks, and verifying the main power supply voltage and breaker status.
Q: Can the CNC controller itself cause electrical malfunctions in a JUGAO press brake?
A: Yes. Controller-related issues such as software glitches, communication failures between the controller and machine components, or axis drive alarm codes can all interrupt normal machine operation.
Q: How often should the electrical cabinet of a JUGAO press brake be inspected?
A: A monthly inspection is recommended for all press brakes, and inspections should be increased to bi-weekly for machines operating in high-production, continuous-run environments.
Conclusion
Troubleshooting electrical malfunctions in JUGAO press brakes is a straightforward process when a structured, systematic approach is followed. By methodically checking the main power supply, electrical cabinet wiring and components, CNC controller and HMI system, backgauge servo drive and motor, and safety sensor array, technicians and operators can quickly pinpoint the root cause of nearly all electrical faults. Mastering these troubleshooting steps not only accelerates machine recovery but also minimizes unplanned production downtime, which is critical for maintaining operational efficiency.
To ensure long-term, trouble-free operation of your JUGAO press brake, regular electrical inspections and a scheduled preventive maintenance program are non-negotiable. These proactive measures eliminate the most common avoidable electrical faults and extend the lifespan of the machine’s critical electrical components. For additional technical guidance, customized troubleshooting support, or detailed maintenance resources for JUGAO press brakes, feel free to contact our professional technical team at any time.






































