Bently Nevada 3500/15 Power Supply

TL;DR: The Bently Nevada 3500/15 is the half-height power supply module that feeds a 3500 machinery protection rack. A rack takes up to two of them, stacked in the left-most slot: the lower module runs as primary, the upper as backup, and either one can power a fully populated rack on its own. Order codes cover Universal AC (85-264 Vac rms), high-voltage DC (88-140 Vdc), low-voltage DC (20-30 Vdc) and the legacy DC variants. Each supply needs a matching Power Input Module (PIM) behind it. TenBN lists the 3500/15 modules and PIMs below with live availability – send us the part number for a quote.

What is the 3500/15?

The 3500/15 converts the field power coming into the rack into the internal voltages the other 3500 modules use, and it is the only path that power takes into the system. It is a half-height main module, so two of them share one full-height front slot position, and each one is paired with a Power Input Module (PIM) that sits in the corresponding rear slot and carries the incoming line terminals and fuses.

Three things make the /15 the most forgiving part of the rack. First, any single supply can run a complete rack – Baker Hughes states there is “no minimum rack load required”, so a lightly populated rack does not need a second module. Second, AC and DC supplies can be mixed freely in the same rack, which is how most TSI packages get a rotating-machine AC primary plus a 24 Vdc battery-backed spare. Third, the modules are hot-swappable: “removing or inserting either power supply module does not disrupt operation of the rack as long as a second power supply is installed”.

3500/15 specifications

Values below are taken from the current datasheet (Baker Hughes document 141530, Universal AC and DC Power Supplies).

Compatible racks and slot positions

The 3500/15 belongs to the 3500 machinery protection system and fits the standard full-size 3500 rack as well as the mini rack. In both, the left-most position is reserved: two half-height power supplies plus the interface module (a 3500/22M TDI on current builds) occupy it, and the remaining 14 slots in a full-size rack (7 in a mini rack) take any mix of monitor, relay, Keyphasor, display or gateway modules.

Because the two supply positions stack in one slot, a rack can never hold more than two power supplies. Fitting only one is allowed – it simply removes redundancy, and the module then becomes non-hot-swappable.

Installation and wiring

Field power lands on the PIM, not on the front module. Universal AC and DC PIMs use connector 118M0915-01 and 118M0915-02 respectively, and the rear input terminals are covered by terminal cover 128085-01 (screw 04310251). If you commission a rack with a single supply, blank panel 131150-01 closes the unused half-slot.

Protection is fuse-based and lives on the PIM. An over-voltage condition opens the PIM fuse; a sustained under-voltage does not damage either the supply or the PIM. Keep these spare fuse part numbers with the rack:

Terminal torque figures, conductor sizing and the grounding/isolation scheme are published in the 3500/15 User Guide (document 129767) rather than in the datasheet. Ask us and we will supply the relevant pages with your quote.

Indicators and what a failure looks like

The 3500/15 has one documented indicator: a green Supply OK LED that, in the datasheet’s words, “indicates when the power supply is operating properly”. The module self-monitors its internal output rails and reports the result through that LED and to the rack, so a loss of OK is a measured condition, not just an input-voltage lamp.

The 3500/15 does not publish a fault-code list. Field diagnosis therefore works by elimination: Supply OK out on one module with the second still green means the rack is still powered and you can hot-swap the suspect module; both out means the incoming line or the PIM fuse is the first thing to check; and a rack-level alarm path (the Rack OK relay, which sits in the TDI’s I/O module and is normally energised) is a rack-health indication only – Baker Hughes is explicit that it should not be wired into an automatic shutdown circuit.

Ordering codes

3500/15 modules are ordered as 3500/15-AA-BB-CC. Positions A and B describe the top and bottom half of the reserved power slot; B can be 00 (no supply) when you want a single supply.

So 3500/15-05-05-00 is a dual Universal AC, non-certified pair, and 3500/15-05-05-02 is the same pair built to Zone 2. Note that the current Universal AC module and PIM are not interchangeable with the legacy AC supply or legacy AC PIMs, and the new HVDC/LVDC parts are not interchangeable with their legacy counterparts – check which generation the rack already holds before ordering a single spare.

3500/15 parts we can supply

Part number

Frequently asked questions

What input voltage does a 3500/15 accept?

It depends on the variant. Universal AC models accept 85-264 Vac rms outside hazardous areas (85-250 Vac rms inside) at 47-63 Hz, with 110 Vac and 220 Vac as the nominal ratings. High-voltage DC models accept 88-140 Vdc and low-voltage DC models accept 20-30 Vdc. At a fully loaded rack the line current peaks at 2.8 A rms on AC, 2.5 A on HVDC and 11.0 A on LVDC.

Can I mix an AC and a DC power supply in the same 3500 rack?

Yes. Baker Hughes allows any combination of AC and DC supplies, which is the usual way to build a redundant TSI power pair: for example a 120 Vac supply in the lower position as primary and a 24 Vdc UPS-fed supply above it as backup. The backup takes over instantly and automatically if the primary drops.

Which slot does the 3500/15 go in?

The left-most position, and only that position. It is a half-height module, so two of them stack in the one full-height slot. The lower module is configured as the primary and the upper as the backup. No other slot in a 3500/05 rack will accept a power supply.

Is the 3500/15 hot-swappable?

Yes, provided the second supply is installed and running. Inserting or removing either module does not interrupt rack operation in a redundant pair. With a single supply fitted, removing it takes the rack down, so treat a one-supply rack as a planned-outage job.

What does it mean when the Supply OK LED goes out?

The green Supply OK LED lights only when the module’s self-test finds its internal output voltages in specification, so an extinguished LED means the module has measured a real fault, not simply an absent input. If the partner supply is still OK the rack stays powered: check the PIM fuse and the incoming line first, then swap the module.

Are new 3500/15 modules compatible with legacy ones?

No. The current Universal AC module and its PIM do not interchange with the legacy 3500 AC supply or the legacy high/low-voltage AC PIMs, and the current HVDC and LVDC parts likewise do not interchange with the legacy DC parts. If a rack already holds a legacy partner, order the matching generation.

What is a Power Input Module and do I need one?

The PIM is a half-height rear module that sits directly behind the 3500/15 and carries the incoming line connection, the connector and the protection fuse. You need one per supply: for example Universal AC module 106M1079-01 pairs with Universal AC PIM 106M1081-01. A supply without its PIM cannot be connected to field power.

Which 3500/15 do I order for a classified hazardous area?

Use option code C. C = 01 gives cNRTLus listing for Class I Division 2, C = 02 gives ATEX, IECEx and CSA certification for Class I Zone 2, both rated T4 over an ambient of -20 to +65 °C. The certification only holds when the module is installed according to drawing 149243 or 149244, so order the drawing set with the module if your site has no copy.

Get a 3500/15 quote

Tell us the full ordering code off the label – for example 3500/15-05-05-02 – or just the PIM number if you are only replacing the rear module. We will confirm availability, lead time and the matching generation for the rack you have. Prices are quoted per enquiry and are not published on this site, and every part we ship is checked against its datasheet revision before dispatch.

Next: how the power supply fits into the rest of the rack in our 3500 system complete guide, or compare the interface modules on the 3500/22M TDI page.