🔧 Schabmuller Traction Motor Encoder Tests

Date: 18/02/2014
Motor Type: Schabmuller Only
Purpose: Encoder Diagnostics & Testing
⚠️ CRITICAL SAFETY NOTICE

After completing encoder tests, you MUST reset SLIP CONTROL to ON before using the truck. Failure to do so can result in unsafe operation.

Overview

This procedure guides you through testing the encoder on Schabmuller traction motors used in Flexi forklifts. The encoder provides speed feedback to the motor controller and is critical for proper traction control.

ℹ️ What is the Encoder?

The encoder is a sensor mounted on the motor that measures rotational speed. It sends pulses to the Zapi controller, allowing precise speed control and slip detection. When the encoder fails, the truck may experience poor acceleration, speed control issues, or slip control problems.

Required Equipment

📋 Before You Begin

  • Zapi Hand Console- Complete with AC adapter lead
  • Lifting Device- Capable of lifting Flexi drive wheels clear of the floor
  • Wooden Blocks- For supporting raised wheels
  • Wheel Chocks- For securing rear wheels
  • Multimeter- For continuity checks

Test Procedures

Check 1: Loose Encoder (Schabmuller Motor Only!)
⚠️ Schabmuller Motors Only This check is specific to Schabmuller motors. The encoder can become loose or partially unseated, causing intermittent faults.

Procedure:

1
Check Encoder Mounting
Verify the encoder is not loose and is fully inserted into the motor housing.
2
Remove Encoder
Carefully remove the encoder from the motor for inspection.
3
Clean & Inspect
Check that the encoder is clean and not contaminated with debris, oil, or metal particles.
4
Reinstall Encoder
Ensure the encoder is fully seated and securely mounted before proceeding to electrical tests.
✅ What to Look For
  • Encoder should be firmly seated with no play
  • Connector should be clean and dry
  • No visible damage to encoder housing or cable
  • No debris or contamination on encoder face
Check 2: Wiring Continuity
ℹ️ About This Test This test verifies electrical continuity between the motor encoder connector and the Zapi controller. A break in any wire will prevent proper encoder operation.

Connection Points:

Motor Plug X Controller Plug E Function
Pin 1 Pin 1 Signal A / Power
Pin 2 Pin 2 Signal B / Ground
Pin 3 Pin 3 Signal C / Shield
Pin 4 Pin 5 Signal D / Reference

Testing Procedure:

1
Disconnect Plugs
Disconnect Plug X at the motor and Plug E at the controller.
2
Set Multimeter to Continuity Mode
Set your multimeter to ohms (Ω) or continuity beep mode.
3
Test Each Wire
Check continuity for each pin pair listed in the table above. You should see close to 0Ω or hear a beep.
4
Check for Shorts
Verify no continuity exists between different pins (they should be isolated from each other).
✅ PASS: All four wires show continuity (<1Ω) and no shorts between wires.
❌ FAIL: If any wire shows no continuity or shorts exist, the cable is damaged and must be repaired or replaced.
Check 3: Encoder Function Test
⚠️ Important Setup Requirements

Before performing this test, the truck must be safely lifted with drive wheels clear of the floor:

  • Lower forks to 100mm from floor (activates full traction speed)
  • Chock rear wheels securely
  • Lift drive wheels clear of floor
  • Support with wooden blocks for safety

Step 1 of 2: Turn SLIP CONTROL OFF

You must disable slip control to perform accurate encoder frequency testing.

1
Press ENTER
Enter the main menu
2
Press ROLL UP until correct menu appears
Navigate to hardware settings menu
3
Press ENTER
Select menu option
4
Press PARAM SET Up & Down buttons TOGETHER
Enter parameter editing mode
5
Press ROLL UP
Navigate to Slip Control setting
6
Press ENTER
Select Slip Control parameter
7
Press ROLL UP
Change value to OFF
8
Press PARAM SET UP
Confirm change
9
Press OUT
Exit to save prompt
10
Press ENTER for YES
Save changes
11
Press OUT
Return to main screen

Console Button Reference:

ENTER
ROLL UP
ROLL DOWN
PARAM SET UP
PARAM SET DOWN
OUT

Step 2 of 2: Encoder Frequency Test

This test compares the SET frequency (commanded by accelerator) with the ACTUAL frequency (measured by encoder).

1
Press ENTER
Enter main menu
2
Press ROLL UP
Navigate to diagnostics
3
Press ENTER twice
Access frequency display mode
4
Press ROLL UP
Select encoder frequency view
5
Slowly increase speed to 80Hz FREQUENCY
Using truck accelerator pedal, gradually increase motor speed until display shows 80Hz
6
Press ROLL UP to view ENCODER reading
Check the actual encoder frequency measurement

Test Results Interpretation:

✅ GOOD ENCODER:

ENCODER value should read 80Hz ± 5Hz(between 75Hz and 85Hz)

This indicates the encoder is correctly measuring motor speed.

❌ FAULTY ENCODER:

ENCODER reads 0.00Hz- Encoder not sending pulses (check wiring, then replace encoder)

ENCODER reads >100Hz- Encoder sending incorrect signal (replace encoder)

If wiring continuity (Check 2) was good, the encoder itself is faulty and must be replaced.

ℹ️ Understanding the Readings
  • FREQUENCY: The commanded motor speed from the controller (SET value)
  • ENCODER: The actual measured speed from the encoder sensor (ACTUAL value)
  • These values should closely match when the encoder is functioning correctly
  • At 80Hz commanded frequency, a properly functioning encoder reports 75-85Hz
🚨 VERY IMPORTANT NOTE

The SLIP CONTROL must be reset to ON before using the truck.

To turn slip control back ON, repeat Step 1 of 2 (Turn SLIP CONTROL OFF) but change the setting from OFF to ON.

Operating the truck with slip control disabled is dangerous and can result in loss of traction control!

Troubleshooting Guide

Symptom Likely Cause Action Required
Encoder reads 0.00Hz constantly No signal from encoder Check wiring continuity (Check 2). If wiring is good, replace encoder.
Encoder reads >100Hz at 80Hz commanded Incorrect encoder pulses Replace encoder (internal fault)
Encoder reading jumps erratically Loose encoder or damaged wiring Reseat encoder firmly (Check 1), inspect wiring for damage
Intermittent encoder faults Contaminated encoder or loose mounting Clean encoder, ensure fully inserted and locked in position
No continuity on specific wire Broken wire in cable harness Repair or replace cable harness between motor and controller

Additional Notes

✅ Best Practices
  • Always perform a physical inspection (Check 1) before electrical tests
  • Document encoder readings for future reference
  • If replacing encoder, verify wiring is correct before final testing
  • After encoder replacement, verify slip control is functioning properly
  • Test truck operation in a safe area after encoder service
ℹ️ Typical Encoder Specifications
  • Type: 80 Pulses per Revolution (Schabmuller Traction Motor)
  • Mounting: Direct mount to motor shaft
  • Output: Digital pulse signal to Zapi controller
  • Function: Speed feedback for traction control and slip detection

Schabmuller Encoder Test Procedure

Date: 18/02/2014

For Flexi forklift traction motors - Service technician reference