Description
Bently Nevada 3500/33-01-01 16-Channel Relay Module
Product Overview
The Bently Nevada 3500/33-01-01 is a full-height 16-channel relay module for the Bently Nevada 3500 Machinery Protection System. It provides sixteen relay outputs that can be driven by alarm and status conditions generated anywhere within the 3500 rack. Unlike a simple bank of fixed alarm contacts, the 3500/33 allows each relay channel to be independently programmed using Alarm Drive Logic. Bently Nevada documents AND/OR logic, voting, normal/true logic, and channel-specific latching functions as part of the module’s programmable relay architecture.
The 3500/33-01-01 configuration identifies the 3500/33 relay-output module with the -01 approval option. Public ordering references identify the final -01 as the CSA/NRTL/C Class I, Division 2 configuration. The module occupies a full-height position in the 3500 rack and operates as an output layer between the machinery-protection logic and external annunciation, shutdown, control, or auxiliary relay circuits.
In a turbine, compressor, pump, motor, or other rotating-equipment installation, this distinction matters. The 3500/33 does not measure vibration itself. Vibration, position, speed, temperature, and other monitored variables are processed by the appropriate 3500 monitor modules. The 3500/33 receives their alarm/status information and converts programmed conditions into physical relay contacts. Bently Nevada specifically states that inputs from any monitor channel or combinations of monitor channels can be used in the relay’s Alarm Drive Logic.
For procurement, the 3500/33-01-01 should therefore be matched against the complete rack configuration rather than selected simply because a project requires “16 relays.” Relay logic, normal-state configuration, contact wiring, approval requirements, and the existing 3500 rack architecture all need to be preserved.
Product Introduction
A 3500 relay module is where machinery-monitoring decisions become physical contacts. The 3500/33-01-01 provides sixteen individually programmable relay outputs, allowing alarm and shutdown schemes to be built from conditions generated by multiple monitor channels.
For a 3500 system upgrade or legacy replacement, the critical checks are not just the connector and module size. Preserve the existing relay logic, contact philosophy, latching behavior, field wiring, and Class I, Division 2 approval requirement.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | 3500/33-01-01 |
| Manufacturer | Bently Nevada |
| Product Family | 3500 Machinery Protection System |
| Product Type | 16-Channel Relay Module |
| Module Format | Full-height 3500 module |
| Number of Relay Outputs | 16 |
| Relay Logic | Independently programmable |
| Alarm Drive Logic | AND / OR logic and voting functions |
| Logic Inputs | Alert, Danger, Not OK, measured variables, and combinations of rack signals |
| Configuration Software | 3500 Rack Configuration Software |
| Output Module Code | -01, 16-Channel Relay Output Module |
| Approval Option | -01, CSA/NRTL/C Class I, Division 2 |
| Relay Arrangement | Relay outputs; exact contact/load configuration must be verified from the applicable datasheet and installed I/O hardware |
| Rack Interface | Bently Nevada 3500 rack |
| Measurement Function | None; receives status/alarm information from 3500 monitoring modules |
| Primary Application | Machinery alarm, shutdown, annunciation, and auxiliary control interface |
Bently Nevada’s current datasheet identifies the 3500/33 as a 16-Channel Relay Module, while the exact -01-01 ordering configuration is independently identified as the 16-channel relay-output module with the CSA/NRTL/C Class I, Division 2 option.
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Major Features / Practical Advantages
Sixteen Independently Programmable Relay Outputs
The primary function is straightforward: sixteen relay outputs are available in one full-height 3500 module. The important part is what drives those outputs. Bently Nevada allows each relay to have its own Alarm Drive Logic rather than forcing every channel to follow the same alarm condition.
This allows one module to handle several different plant functions—for example, individual machine alarms, grouped alarms, shutdown commands, annunciator signals, or auxiliary control logic—provided the application has been engineered for those functions.
Programmable Alarm Drive Logic
The 3500/33 can use alarm conditions from the 3500 rack as logic inputs. Bently Nevada specifically identifies Alert, Danger, Not OK, and individual measured variables as available sources. Multiple monitor channels can also be combined within the relay logic.
That is considerably different from wiring a fixed relay directly to one monitor alarm. The 3500/33 can implement a plant-specific relationship between several machinery conditions and one physical output.
AND/OR Logic and Voting
The relay architecture supports AND and OR logic and voting functions. This is useful where a shutdown or annunciation should depend on multiple conditions rather than a single measurement.
For example, a plant may require several monitored channels to satisfy a defined condition before a particular relay changes state. The actual logic is configuration-specific, so the stored 3500 rack configuration should be treated as an engineering record.
Latching Capability
Bently Nevada documents channel-level latching capability as part of the 3500/33 relay logic. This is useful for applications where an alarm or trip must remain indicated after the initiating condition disappears until the operator or control system performs the appropriate reset.
Do not assume every installed relay is latched. The configuration determines the actual behavior.
Class I, Division 2 Configuration
The final -01 of 3500/33-01-01 identifies the documented CSA/NRTL/C Class I, Division 2 approval configuration. This matters when the relay module is installed as part of machinery-monitoring equipment serving a classified area.
Approval status should be matched to the actual installation. A visually identical relay module with a different approval suffix should not automatically be considered equivalent.
Integrated 3500 Rack Architecture
The 3500/33 is one of the output modules within the modular 3500 machinery-protection rack. Bently Nevada’s system documentation shows that relay modules can receive information from the broader rack architecture, allowing measured-variable and alarm information from other 3500 modules to participate in relay logic.
This is why the module should not be evaluated as an isolated relay board. Its useful function depends on the rack’s monitors, TDI/rack interface, configuration software, and field wiring.
No Measurement Function
A common procurement error is to describe the 3500/33 as a vibration monitor. It is not.
The actual measurement is performed by modules such as the 3500/40M, 3500/42M, 3500/45, 3500/50M, 3500/65, and other appropriate 3500 modules. The 3500/33 acts on the resulting status and measurement information. Bently Nevada’s system architecture explicitly separates monitoring modules from relay-output modules.
Related Products
- 3500/32M — Four-channel relay module with four programmable relay outputs; useful where fewer physical relay contacts are required.
- 3500/34 — Four-channel TMR relay module for applications requiring a different relay architecture.
- 3500/22M — Transient Data Interface module providing the primary rack interface and data-management functions.
- 3500/40M — Proximitor monitor for radial vibration, position, eccentricity, and related measurements.
- 3500/42M — Proximity/seismic monitor for vibration, position, and other machinery-protection measurements.
- 3500/45 — Position monitor for shaft and casing position applications.
- 3500/50M — Tachometer module for speed and rotational measurements.
- 3500/65 — 16-channel temperature monitor for machinery temperature measurements.
- 3500/15 — AC/DC power supply module for the 3500 rack.
These modules perform different functions. The 3500/33-01-01 should not be substituted for a measurement module simply because both occupy the same general 3500 rack architecture. Bently Nevada identifies the 3500/33 separately as the 16-channel relay-output module.
FAQ
What is Bently Nevada 3500/33-01-01?
It is a 16-channel relay module for the Bently Nevada 3500 Machinery Protection System. Each of its sixteen relay outputs can be independently programmed using the 3500 Alarm Drive Logic.
Is 3500/33-01-01 a vibration monitor?
No. It does not perform the primary vibration, position, speed, or temperature measurement. Those functions are performed by dedicated 3500 monitor modules. The 3500/33 converts configured rack conditions into relay outputs.
What does the first “-01” mean?
In the documented ordering structure, the first -01 identifies the 16-channel relay output module. The final -01 identifies the CSA/NRTL/C Class I, Division 2 approval configuration.
Can each relay use different alarm logic?
Yes. Bently Nevada states that each relay can be independently programmed for Alarm Drive Logic. The logic can use Alert, Danger, Not OK, individual measured variables, and combinations of monitor-channel conditions.
Can I hot-swap the 3500/33?
Do not assume that removing the module under power is acceptable simply because the 3500 system is modular. Relay outputs may be connected directly to shutdown, annunciation, or auxiliary control circuits. Follow the approved 3500 maintenance procedure and plant isolation requirements before removing the module.
Does the 3500/33 retain the relay configuration?
The relay behavior is defined by the 3500 rack configuration. Before replacing a module, obtain and preserve the current configuration using the applicable 3500 Rack Configuration Software and maintenance procedures. Do not rely on memory or a generic factory configuration to reproduce a safety-related relay scheme.
Can 3500/33 replace 3500/32M?
Not as a direct functional assumption. The 3500/32M provides four relay channels, whereas the 3500/33 provides sixteen. The physical rack architecture may be related, but the channel count, field wiring, logic allocation, and project configuration are different.
Is the 3500/33-01-01 suitable for hazardous areas?
The exact -01-01 ordering configuration is documented with the CSA/NRTL/C Class I, Division 2 approval option. Confirm that the certification matches the installation’s hazardous-area classification and the complete rack/system approval requirements.
What should I verify before purchasing a replacement?
Verify the complete part number, module label, approval marking, rack type, relay logic configuration, field terminal arrangement, contact requirements, and existing 3500 software configuration. For a used or New Surplus module, request evidence of functional relay testing rather than relying only on a power-up test.
Procurement Note
The Bently Nevada 3500/33-01-01 is a configuration-dependent machinery-protection output module. The important procurement distinction is:
3500/33 → 16-channel relay module
First -01 → 16-channel relay output configuration
Final -01 → CSA/NRTL/C Class I, Division 2 approval configuration
Before installation, preserve the existing Alarm Drive Logic and confirm every field relay circuit. In a turbine or compressor shutdown system, a relay that passes a basic continuity test can still be wrong if its normally energized/de-energized behavior, latching logic, voting arrangement, or field wiring differs from the original configuration.
The current Bently Nevada documentation identifies the 3500/33 16-Channel Relay Module as a supported 3500 Machinery Protection System component and provides the governing technical information for its relay logic and application.
