We developed a custom solution for 8.H120.4A51.5000, for heavy motor and generator systems where 5000 PPR push-pull feedback must stay stable under high pulse density, hollow-shaft mounting, torque-arm movement, and EMC noise.

Model reading:

  • 4 = 150 mm torque arm
  • A = 12 mm blind hollow shaft with central fastening
  • 5 = push-pull with inverted signals, 10–30 VDC
  • 1 = radial PVC cable, 1 m
  • 5000 = 5000 pulses per revolution

Typical production lead time: 15 working days.

At 5000 PPR, the first weak point is usually not the encoder optics. It is the counter frequency margin. The H120 platform supports 300 kHz maximum pulse frequency, but at high RPM the PLC or drive counter, cable routing, and shielding must be checked first. A high-PPR encoder does not forgive weak edge detection.

Where the System Fails First

The 12 mm blind hollow shaft and 150 mm torque arm must be mechanically controlled. If the shaft fit is loose or the torque arm restrains the housing incorrectly, the signal normally shows phase jitter before any visible bearing damage appears.

For standard push-pull output, the cable boundary is also tighter than many installers expect. The datasheet gives 150 m maximum cable length at 80 kHz for push-pull. This model uses only 1 m radial cable, so cable length is not the main issue, but shield termination and grounding still decide whether the 5000 PPR signal is readable.

Typical failure points:

  • Counter bandwidth too low → missed pulses
  • Poor torque-arm restraint → housing oscillation
  • Loose blind-shaft fit → phase jitter
  • Shield break → unstable A/B edges
  • Grounding error → reference pulse noise
  • High shaft current without isolation control → feedback damage risk

Mechanical Boundary

H120 is built for heavy machines: 2.5 kV bearing isolation, HD-Safety-Lock™, dual shaft protection, IP67, seawater-resistant housing, 475 N radial load, 375 N axial load, and -40 °C to +100 °C operating range. These margins are strong, but they do not fix a loose hollow shaft or a badly constrained torque arm.

Installation Notes

  • Keep the model format as 8.H120.4A51.5000
  • Confirm counter frequency at real RPM before installation
  • Control the 12 mm blind hollow shaft fit and central fastening
  • Install the 150 mm torque arm without forcing the housing
  • Keep cable shielding continuous from encoder to cabinet
  • Separate encoder wiring from inverter and motor power cables
  • Check shaft-current isolation before blaming the output circuit

Key Data

  • Model: 8.H120.4A51.5000
  • Type: Heavy-duty blind hollow shaft incremental encoder
  • Resolution: 5000 PPR
  • Output: Push-pull with inverted signals
  • Supply voltage: 10–30 VDC
  • Max frequency: 300 kHz
  • Max cable length: 150 m at 80 kHz
  • Shaft: 12 mm blind hollow shaft with central fastening
  • Mounting: 150 mm torque arm
  • Connection: 1 m radial PVC cable
  • Protection: IP67
  • Temperature: -40 °C to +100 °C
  • Shaft load: 475 N radial / 375 N axial
  • Shock: 2000 m/s², 6 ms
  • Vibration: 150 m/s², 10–2000 Hz