Bently Nevada 136703-01 3500/50 I/O Modules

The Bently Nevada 136703-01, also cataloged as the 3500/50 I/O Module with Internal Barriers and Internal Termination, operates as a dedicated hardware component for processing tachometer and shaft speed signals within Bently Nevada 3500 Series Machinery Protection Systems.

Hardware Specifications

Eddy-Current Probe Scaling and Gap Voltage Validation

The 136703-01 I/O module conditions transducer signals originating from proximity probe systems across a 30 kHz signal bandwidth. Correct speed pulse acquisition and phase reference timing require precise eddy-current probe scaling and physical transducer gap verification. Verifying target gap voltage validation (-10 VDC targets) during baseline setup prevents pulse distortion, mitigating cross-talk suppression degradation across adjacent channel connections in high-density rack backplanes.

Frequently Asked Questions

Q: Does the 136703-01 module require external zener barrier blocks for hazardous area transducer connections?

A: No, the module integrates internal galvanically isolated barriers directly on the board, allowing direct field wiring termination without external barrier hardware.

Q: Can this rear I/O module be hot-swapped while the 3500 rack remains powered?

A: Yes, rear I/O modules in the 3500 system can be removed or inserted under backplane power, provided the associated main front module is temporarily disengaged or set to maintenance mode.

Field Installation Guidelines

1. Power down the channel slot or confirm system maintenance overrides before installing the module into the rear slot of the 3500 rack chassis.
2. Align the board edges with the top and bottom card guides of the designated slot and slide the module inward until the backplane connectors seat completely.
3. Tighten the top and bottom captive screws by hand to secure the faceplate to the rack frame and ensure solid mechanical chassis grounding.
4. Wire field transducer leads directly to the internal termination screw blocks, taking care not to bridge adjacent intrinsically safe terminals.
5. Connect cable shields to the dedicated rack ground bus bar to prevent high-frequency electro-magnetic interference from corrupting speed pulse edge detection.