FG40KK-2000G-90G-NG should be matched as a 2000 PPR dual-terminal-box feedback encoder, where EncoderWorks can configure a custom compatible replacement solution only if the counter scaling, A/B 90° phase relationship, inverted channels, NG reference pulse, KK wiring layout, EMC grounding, and coupling preload remain unchanged. The main failure boundary is a drive system that receives clean pulses but calculates the wrong speed, loses reference repeatability, or develops direction instability after replacement. Typical production lead time: 15 working days.
This configuration belongs to the FG 40 heavy-duty incremental encoder platform. It provides 2000 pulses per revolution with square-wave output, basic channel 0° A, pulse channel 90° B, inverted channels, and an NG reference pulse with inverted signal. The KK version should be treated as a dual terminal-box or redundant-style wiring layout rather than a single-terminal-box K encoder. Replacement work should focus on pulse rate, counter input mode, A/B phase accuracy, N pulse timing, output voltage level, terminal-box routing, shield bonding, and shaft coupling alignment.
System Limits
The first system limit is 2000 PPR counter scaling. If the controller was configured for 1200, 1024, 2048, 2500, or another pulse count, the drive may still receive stable A/B signals while speed and position values are converted incorrectly. Edge-counting mode, maximum input frequency, acceleration behavior, and direction detection should be checked before the replacement is accepted.
The second limit is A/B/N signal integrity. The controller must receive A, /A, B, /B, N, and /N with the expected 90° phase relationship and repeatable reference-pulse behavior. If the inverted channels, phase displacement, or N pulse wiring changes, the machine may run during normal motion but fail during homing, zero return, or direction reversal.
The third limit is mechanical and EMC installation. Coupling misalignment, axial preload, radial load, weak shield grounding, or signal wiring routed near inverter and motor cables can degrade edge quality and shorten bearing life. The KK dual terminal-box layout must also be preserved if the installed machine separates feedback wiring, redundant paths, or cabinet-side service access.
Wiring & Installation
Before replacement, record the 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 how both terminal boxes are used: redundant feedback, separated signal routing, signal distribution, or maintenance isolation.
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 cables away from inverter output, motor, brake, contactor, and solenoid wiring. Use low-impedance grounding, maintain shield continuity, tighten cable glands, and seal the terminal boxes before startup. After commissioning, verify pulse count, speed scaling, direction, N reference repeatability, terminal-box separation, and signal stability over the full operating speed range.
Custom Compatible Solution
EncoderWorks can configure the replacement around the installed drive and counter system:
- Match 2000 PPR square-wave incremental output with A/B 90° phase relationship and inverted channels
- Preserve NG reference pulse behavior, KK dual-terminal-box layout, supply voltage, output level, and counter input compatibility
- Adapt the FG 40 mechanical envelope, flange or foot mounting requirement, shaft interface, coupling alignment, and cable-gland layout
- Review counter scaling, shield grounding, EMC routing, terminal separation, bearing load, cable sealing, and reference-pulse repeatability
Key Data
| Item | Data |
|---|---|
| Model | FG40KK-2000G-90G-NG |
| Encoder type | Heavy-duty incremental encoder |
| Series | FG 40 |
| Connection structure | KK dual terminal box / redundant-style version |
| Pulses per revolution | 2000 PPR |
| Pulse category | Standard 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 | 2000 PPR scaling, A/B phase, NG reference pulse, terminal-box wiring, EMC grounding |
