For FGHJ4S-1024G-90G-NG/20P, EncoderWorks can configure a custom compatible replacement solution only if the 1024 PPR nickel-disk scaling, J isolated-bearing construction, S single 15-pole industrial plug mapping, /20P hollow-shaft fit, A/B 90° phase relationship, inverted signal pairs, N marker behavior, torque bracket freedom, adapter-shaft run-out, and shielded signal transmission remain matched. The main failure boundary is a hollow-shaft drive that receives pulses but develops wrong speed scaling, direction reversal, zero-reference loss, plug-side signal errors, or bearing-current damage because the isolation boundary, plug pinout, bore fit, or torque support has changed. Typical production lead time: 15 working days.
This model belongs to the FGHJ 4 hollow-shaft incremental encoder platform. The 1024 PPR value is a preferred nickel-disk pulse rate, so replacement work should focus on stable reference scaling, A/B/N signal continuity, plug pin assignment, and controlled hollow-shaft mounting rather than high-pulse glass-disk frequency limits. The J construction adds an isolation requirement for applications where motor shaft currents or potential differences could otherwise pass through the encoder bearings. The S version should be handled as a single 15-pole industrial plug encoder, not as an SS dual-plug redundant version or a KK dual-terminal-box configuration.
System Limits
The first system limit is 1024 PPR reference scaling. If the controller is configured for 1000, 1200, 2048, or another pulse value, the encoder may output clean square-wave signals while speed, travel, and synchronization values become wrong. Edge-counting mode, gear ratio, direction logic, and machine conversion factors should be checked before startup.
The second limit is S plug signal mapping. The 15-pole plug must preserve A, /A, B, /B, N, and /N exactly as expected by the receiving counter. If one phase pair is swapped, one inverted output is omitted, one shield path is weak, or the N marker is assigned to the wrong pin, the machine may fail during homing, direction reversal, or synchronized positioning.
The third limit is hollow-shaft mechanics and isolation. The /20P bore must fit the prepared shaft without forcing, and the torque bracket must compensate shaft movement without loading the bearings. Adapter-shaft radial eccentricity, axial motion, torque-arm binding, shaft shock, or loss of bearing isolation can shorten bearing life and appear as pulse jitter or intermittent reference errors.
Wiring & Installation
Before replacement, record the 15-pole plug assignment for supply voltage, GND, shield, A/B/N signal sequence, inverted outputs, and any LED-check or diagnostic signal used by the control system. Confirm that the counter input is scaled for 1024 PPR and that the application expects the same 0°/90° phase sequence and N marker behavior.
During mechanical installation, clean the customer shaft, centering surface, bolting faces, and fastening threads. Align the adapter shaft carefully, avoid hammering the encoder, and do not pull the hollow-shaft device into position by force. The torque bracket should remain free at the link heads and should not transmit bending load into the bearings.
For signal stability, route each non-inverted and inverted signal pair through shielded twisted conductors. Keep feedback wiring away from inverter, motor, brake, contactor, and power cables, and maintain continuous shield bonding. After commissioning, verify pulse count, direction, N marker repeatability, plug seating, shield continuity, isolation requirement, and stable operation through the required speed range.
Custom Compatible Solution
EncoderWorks can configure the replacement around the installed FGHJ 4 isolated hollow-shaft and single-plug interface:
- Match 1024 PPR square-wave incremental output with 0°/90° channel behavior and inverted signal pairs
- Preserve J isolated-bearing construction, S single 15-pole industrial plug layout, N marker behavior, supply range, and output level
- Adapt the FGHJ 4 /20P hollow-shaft bore, adapter-shaft fit, torque bracket position, sealing boundary, and plug orientation
- Review 100 kHz / 150 kHz frequency margin, shielded twisted-pair routing, plug pin mapping, bearing isolation, shaft load, and marker repeatability
Key Data
| Item | Data |
|---|---|
| Model | FGHJ4S-1024G-90G-NG/20P |
| Encoder type | Incremental hollow-shaft encoder |
| Series | FGHJ 4 |
| Bearing construction | Isolated bearings |
| Connection structure | S single 15-pole industrial plug |
| Pulses per revolution | 1024 PPR |
| Pulse disk class | Preferred nickel-disk pulse rate |
| Signal output | Square wave, 0° and 90° channels |
| Inverted signals | Yes, Option G |
| Marker pulse | Option N with inverted marker signal |
| Hollow-shaft interface | /20P |
| Supply voltage | 12–30 VDC |
| Output type | Differential line-driver / push-pull style output |
| Frequency range | 0–100 kHz standard, up to 150 kHz if specified |
| Protection class | IP55 standard; higher protection depends on connection and sealing configuration |
| Mechanical checks | /20P bore fit, adapter-shaft run-out, torque bracket freedom, bearing load, isolation boundary |
| Key replacement checks | 1024 PPR scaling, isolated bearings, S plug mapping, A/B phase, N marker, shielding |
Related Models
- FGHJ40S-1024G-90G-NG/20P Hollow-Shaft Encoder with Isolated EMC Plug Feedback
- FGHJ4KK-2048G-90G-NG/20P Hollow-Shaft Encoder with Isolated Dual-Box Feedback
- FGHJ4K-2048G-90G-NG/20P Hollow-Shaft Encoder with Isolated Terminal-Box Feedback
- FGHJ40KK-2048G-90G-NG/20P Hollow-Shaft Encoder with Isolated Dual-Box Feedback
