FG40K-10000G-90G-NG has to be treated as a high-pulse radial-terminal-box feedback encoder, where EncoderWorks can configure a custom compatible replacement solution only if the 10000 PPR output, A/B 90° phase relationship, inverted channels, NG reference pulse, K terminal-box wiring, EMC cable-gland shielding, counter frequency margin, and coupling preload remain unchanged. The main failure boundary is missed edges or unstable direction detection at operating speed, even when the encoder appears correct during slow rotation. Typical production lead time: 15 working days.
This configuration belongs to the FG 40 heavy-duty incremental encoder platform. It uses 10000 pulses per revolution with square-wave output, basic channel 0° A and pulse channel 90° B, inverted signal pairs, and a mechanically defined NG reference pulse with inverted signal. The K version should be handled as a radial single-terminal-box encoder, not as a KK dual-terminal-box version. Replacement work should focus on maximum shaft speed, controller input bandwidth, edge-counting mode, A/B phase accuracy, N reference repeatability, shield termination, terminal-box sealing, and mechanical coupling alignment.
System Limits
The first system limit is counter frequency. At 10000 PPR, the controller input frequency depends directly on shaft speed and counting mode. If the PLC or drive counter is close to its bandwidth limit, the machine may count correctly at low speed but lose edges during acceleration, reversing motion, or full-speed operation.
The second limit is A/B/N signal quality. The controller must receive A, /A, B, /B, N, and /N with clean edges, correct 90° phase displacement, and repeatable reference-pulse timing. With this pulse density, weak shield bonding, long cable runs, poor input thresholds, or inverter noise can create false edges, direction jitter, or reference-position drift.
The third limit is the radial terminal box and coupling interface. Moisture in the terminal box, loose cable glands, long exposed shield drains, or poor grounding can reduce noise immunity. Coupling misalignment, axial preload, radial load, or bearing stress can also modulate edge timing and shorten service life.
Wiring & Installation
Before replacement, record the radial terminal-box wiring for A, /A, B, /B, N, /N, supply voltage, GND, shield, and any diagnostic or error output used by the machine. Confirm the cable diameter, gland sealing condition, shield contact method, grounding strap, and controller counter frequency margin at the highest shaft speed.
During installation, align the coupling without force and do not strike the shaft or housing. Keep angular error, axial offset, and parallel displacement within the coupling tolerance used on the machine. Route signal and supply wiring away from inverter output, motor power lines, brakes, contactors, and solenoid valves. Tighten the cable gland and blanking plug, maintain low-impedance shield continuity, and close the terminal-box cover without trapping the cable. After commissioning, verify pulse count, direction, N reference repeatability, counter margin, terminal-box sealing, and signal stability at maximum operating speed.
Custom Compatible Solution
EncoderWorks can configure the replacement around the installed drive and counter system:
- Match 10000 PPR square-wave incremental output with A/B 90° phase relationship and inverted channels
- Preserve NG reference pulse behavior, K radial terminal-box layout, supply voltage, output level, and counter input compatibility
- Adapt the FG 40 mechanical envelope, shaft interface, flange or foot mounting requirement, coupling alignment, and cable-gland layout
- Review 200 kHz counter margin, shield grounding, EMC routing, terminal-box sealing, bearing load, and reference-pulse repeatability
Key Data
| Item | Data |
|---|---|
| Model | FG40K-10000G-90G-NG |
| Encoder type | Heavy-duty incremental encoder |
| Series | FG 40 |
| Connection structure | K radial terminal box |
| Pulses per revolution | 10000 PPR |
| Pulse category | Special pulse rate |
| Signal output | Square wave A/B, 90° phase |
| Inverted signals | Yes |
| Reference pulse | NG, with inverted signal |
| Supply voltage | 12–30 VDC |
| Output type | Push-pull line driver |
| Max frequency | 200 kHz |
| Standard shaft | 11j6 × 30 mm |
| Optional shaft | 14j6 × 30 mm |
| Key checks | 200 kHz counter margin, A/B phase, NG reference pulse, terminal-box shielding, coupling preload |
