Name: Bently Nevada 3500/32M 125720‑01 4‑Channel Relay Control Module - MASSIVE
Brand: Bently Nevada

Description

Product Introduction

The 125720‑01 is the factory‑serviceable relay small daughter‑board for Bently Nevada 3500/32M 4‑Channel Relay Control ModuleBaker Hugh…. This internal PCB unit carries four SPDT epoxy‑sealed relay assemblies with built‑in arc suppression components. It executes physical contact switching commanded by the main logic board (149986‑02).

Each relay channel supports Alarm Drive Logic, accepting Alert, Danger, Not‑OK and PPL status signals from any monitor channel within the 3500 rack. AND / OR voting, latching function, Normally‑Energized / Normally‑De‑Energized modes are configured via the main module hardware switches and rack configuration software.

This small card is only for repair replacement. It cannot be directly inserted into 3500 rack slots without the main module mechanical housing & logic motherboard.

125720‑01

Key Technical Specifications

Item	Parameter
Part Number	125720‑01 (Relay Output Small Daughter‑Card)Baker Hugh…
Belongs To	3500/32M full‑height relay module (main board:149986‑02)
Channel Count	4 independent SPDT relay channels
Relay Contact Rating	5 A @240 VAC / 30 VDC per channel
Relay Construction	Epoxy‑sealed, integrated arc suppressor
Mechanical Life	100 000 cycles under full rated resistive load
Operation Trigger	Controlled by 3500/32M main logic board back‑plane signal
Operating Environment	‑30 °C ~ +65 °C; 0‑95 %RH non‑condensing
Compatibility	Only fit inside 3500/32M module enclosure; not rack‑mountable standalone
Software Requirement	Same as 3500/32M: Rack Configuration Software ≥V4.50
Purpose	Repair spare part, replacement for damaged relay output PCB inside 3500/32MBaker Hugh…

Distinction note：

149986‑02: Complete full‑height rack‑mount 3500/32M module (main logic board + installed 125720‑01 small relay card inside)

125720‑01: Inner small relay daughter‑card only, spare part for maintenance, no front panel, no rack mounting hardwareBaker Hugh…

Typical Applications

On‑site repair & component‑level maintenance for existing 3500/32M modules in turbine, compressor machinery‑protection racks.
Restore relay output function after contact ablation, surge damage or internal relay failure on original 3500/32M.
Used in power‑generation, petrochemical rotating‑equipment protection systems, where 3500/32M performs voting‑logic trip & alarm interlock for steam turbines, gas turbines, large centrifugal compressors.

Important: This small card cannot substitute a complete 3500/32M for new‑project rack commissioning.

Common Technical Pitfalls & Avoidance Guidelines

4.1 Cannot operate as standalone rack module

125720‑01 is an internal daughter‑board only. It has no back‑plane connector, no front‑panel LED, no slot mechanical latch. Attempting direct rack insertion leads to total non‑function and physical damage. Must install inside original 3500/32M full‑height housing with matching main logic board 149986‑02Baker Hugh….

4.2 Mis‑match spare‑card revision

Confirm hardware revision compatibility before replacement. Wrong revision may cause relay mis‑fire, latching malfunction, or communication error between small relay card and main logic board.

4.3 Over‑load relay contacts after replacement

Even with brand‑new 125720‑01 small card, do not drive high‑power inductive loads directly. Solenoids, contactors must use external intermediate isolation relays. Inductive surge will burn relay contacts again in short service time.

4.4 Ignore static‑protection during replacement

This PCB contains sensitive control circuits. Always apply anti‑static wrist strap when swapping this small daughter‑card. Static discharge can destroy on‑board drive chips without visible burn marks.

4.5 Skip full logic verification after replacement

After installing new 125720‑01 small card, download configuration again and perform full channel function test: verify AND/OR voting, latching, NE/NDE switch setting, alarm & trip output action. Do not put into service without loop test.