KUKA KSS00019 Power Supply Error – Causes, Symptoms & How to Fix

Error Code Overview

• Error Code: KSS00019
• Category: Power / Controller / Electrical
• Severity: High
• System: KRC Controller / KUKA Servo Drives (KSP/KPP)
• Impact: Robot motion stops to prevent controller, drive, or motor damage

Quick Fix for KUKA KSS00019 Power Supply Error

If KUKA KSS00019 Power Supply Error appears, perform these immediate checks:

• Stop all robot motion immediately
• Inspect the incoming mains power supply
• Check all breakers and cabinet fuses
• Verify voltage at the KRC controller input terminals
• Inspect power cables and connectors for looseness or damage
• Reset the alarm through SmartHMI after inspection

In many cases, KSS00019 is triggered by unstable facility power, loose wiring, or temporary voltage drops.

What Does KUKA KSS00019 Mean?

KUKA KSS00019 Power Supply Error indicates that the robot controller has detected abnormal electrical conditions affecting the main power system.

Th is alarm is typically generated when:

• Input voltage drops below acceptable limits
• Input voltage exceeds safe operating range
• Power interruptions or phase imbalance are detected
• Internal power supply modules fail to regulate voltage correctly

In simple terms, the robot has stopped because the controller cannot guarantee safe operation under the current power conditions.

Common Causes of KUKA KSS00019

External Power Supply Instability

Unstable incoming plant power is one of the most common causes of KSS00019.

Typical issues include:

• Voltage sag during machine startup
• Facility-wide power fluctuations
• Poor generator or UPS regulation
• Sudden load spikes from nearby equipment

Three-Phase Power Loss

Missing or imbalanced phases can prevent the KPP module from operating normally.

Possible reasons:

• Blown fuseon one phase
• Loose terminal connection
• Damaged incoming power cable
• Failed disconnect switch

KPP Power Module Failure

A faulty KUKA KPP power pack may fail to regulate the DC bus properly.

Common internal failures include:

• Rectifier bridge damage
• Capacitor degradation
• Internal overheating
• Power transistor faults

CCU Power Distribution Fault

The Cabinet Control Unit (CCU) distributes internal control voltage throughout the cabinet.

If the CCU fails:

• 24V logic supply may become unstable
• Safety bus communication may drop
• Drives may shut down unexpectedly

Main Contactor Wear or Damage

Worn contactors may create intermittent voltage drops under load.

Signs include:

• Arcing marks
• Burned contact surfaces
• Audible chatter during startup
• Excessive heat buildup

Recommended Replacement Parts

Component	Description	Recommended SKU / Type
KUKA KPP Power Pack	Main DC bus & 24V supply	00-198-263 (KPP 600-20)
Cabinet Control Unit (CCU)	Power distribution & logic control	KRC4 standard CCU
Main Power Contactor	High-current switching unit	KUKA OEM Contactors
Line Filter / Choke	Electromagnetic interference protection	KRC4 Integrated Filter

How to Troubleshoot KUKA KSS00019

Step 1 – Verify Incoming Power Supply

Measure and confirm:

• Correct mains voltage
• Stable frequency
• Proper three-phase balance

Also inspect:

• Breakers
• Fuses
• Disconnect switches

Step 2 – Inspect Power Wiring

Check for:

• Loose terminals
• Burned connectors
• Cable insulation damage
• Grounding faults

Poor connections can create intermittent voltage loss that triggers KSS00019.

Step 3 – Check Internal Cabinet Components

Inspect the KRC cabinet for:

• Burn markson power modules
• Fault LEDson KPP/KSP units
• Loose internal connectors
• Overheated wiring or terminals

Step 4 – Review System Load

Determine whether overload is present:

• Disconnect auxiliary equipment temporarily
• Isolate robot axes if needed
• Review current draw logs in diagnostics

Step 5 – Reset and Test

After repairs:

• Clear the alarm in SmartHMI
• Restart the KRC controller
• Run the robot at low speed
• Monitor voltage stability during motion

Professional Diagnostic Tips

Experienced technicians often use the following methods when diagnosing recurring KSS00019 alarms:

• Measure voltage ripple using an oscilloscope
• Monitor voltage drop during robot acceleration
• Log intermittent fluctuations over time
• Inspect cabinet cooling fans and airflow
• Compare alarm timing against facility power events

Most recurring KSS00019 faults are traced to unstable plant power or aging cabinet power components.

How to Fix KUKA KSS00019

Dependingon the root cause, repair may involve:

• Replacing blown fuses or resetting breakers
• Repairing damaged power wiring
• Tightening loose electrical terminals
• Replacing faulty KPP or CCU modules
• Replacing worn contactors
• Correcting grounding problems
• Reducing excessive electrical load

How to Prevent KUKA KSS00019

To reduce future power supply faults:

• Install surge protection or voltage stabilizers
• Inspect cabinet wiring during preventive maintenance
• Replace aging contactors proactively
• Keep cabinet cooling systems clean
• Monitor facility power quality regularly

Related Errors

• KUKA KSS01305 DC Bus Undervoltage Error– DC bus voltage below threshold.
• KUKA KSS01306 DC Bus Overvoltage Error – DC bus voltage above limit.
• KUKA KSS01310 Power Supply Module Error– Internal module failure.
• KUKA KSS00406 Position Deviation Error – axis deviation caused by torque fluctuations.
• KUKA KSS01406 Motor Overheating Error – Excessive current draw from unstable power.

⚠️ Closely related to controller power stability, DC bus conditions, and motor protection systems.

FAQ

Can the robot run with KSS00019 active?

No. Robot motion remains disabled until stable power is restored and the fault is cleared.

Why does KSS00019 happen randomly?

Random occurrences are usually caused by:

• Intermittent power fluctuations
• Loose wiring
• Weak contactors
• Internal power module degradation

Can unstable power damage a KUKA robot?

Yes. Long-term unstable voltage can damage:

• Servo drives
• Motors
• Controller boards
• Internal power modules

How do I clear KUKA KSS00019?

After correcting the issue:

1. Restore stable power
2. Reset the fault in SmartHMI
3. Restart the controller
4. Test robot motion at low speed