We developed a custom solution for 8.H120.356A.1024.0020, for heavy motor and generator systems where 1024 PPR power push-pull feedback must stay stable under 25 mm through-shaft mounting, torque-arm restraint, 2 m cable routing, and shaft-current risk.

Model reading:

  • 3 = 100 mm torque arm
  • 5 = 25 mm through hollow shaft
  • 6 = power push-pull with inverted signals, 10–30 VDC
  • A = radial PVC cable, special length
  • 1024 = 1024 pulses per revolution
  • 0020 = 2 m cable length

Typical production lead time: 15 working days.

At 1024 PPR, this model is not usually limited by counter bandwidth first. The first weak point is normally 25 mm shaft fit, torque-arm geometry, cable shielding, and grounding continuity. The power push-pull output gives stronger load capability than standard push-pull, but it cannot compensate for poor shaft mounting or a broken shield path.

Where the System Fails First

The 25 mm through hollow shaft must stay concentric with the machine shaft. If the shaft fit is loose or the motor shaft has runout, the encoder usually shows A/B phase jitter before visible bearing damage appears.

The 100 mm torque arm is a middle-length restraint. It gives more tolerance than a short arm, but less reach than the 150 mm version. If it is installed under preload, the housing follows machine vibration and the signal becomes unstable under load.

For the power push-pull output, the datasheet gives 350 m cable length at 100 kHz. This model uses only a 2 m radial cable, so cable length is not the main limit. The real field problem is routing: inverter output cables, motor power lines, and weak cabinet grounding can still destroy edge timing at the counter input.

Typical failure points:

  • Loose 25 mm hollow-shaft fit → A/B phase jitter
  • Preloaded 100 mm torque arm → housing vibration
  • Poor cable shielding → unstable pulse edges
  • Grounding error → reference signal noise
  • Counter filtering mismatch → false counts
  • Shaft current without isolation control → feedback damage risk

Mechanical Boundary

H120 is built for large electric machines, with 2.5 kV bearing isolation, HD-Safety-Lock™, double shaft protection, IP67, seawater-resistant housing, 475 N radial load, 375 N axial load, and -40 °C to +100 °C operation. These margins only work when the shaft fit, torque-arm installation, cable shielding, and grounding path are controlled.

Installation Notes

  • Keep the model format as 8.H120.356A.1024.0020
  • Check the 25 mm through hollow shaft fit before checking electronics
  • Install the 100 mm torque arm without side-loading the housing
  • Route the 2 m cable away from inverter and motor power wiring
  • Keep shielding continuous from encoder to cabinet
  • Confirm counter settings at real RPM and 1024 PPR
  • Check shaft-current isolation before replacing the encoder

Key Data

  • Model: 8.H120.356A.1024.0020
  • Type: Heavy-duty through hollow shaft incremental encoder
  • Resolution: 1024 PPR
  • Output: Power push-pull with inverted signals
  • Supply voltage: 10–30 VDC
  • Max frequency: 300 kHz
  • Max cable length: 350 m at 100 kHz
  • Shaft: 25 mm through hollow shaft
  • Mounting: 100 mm torque arm
  • Connection: 2 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