The Core Power Supply in a Speedtronic Mark V

Each populated core of a GE Speedtronic Mark V has its own DC power supply, and that board is the DS200TCPS. It accepts the panel's 125 VDC bus and regulates it down into the supplies the core's electronics actually use: a +5 VDC logic rail, trimmed to value with an onboard potentiometer during replacement, plus the analog and servo-drive rails that the core needs, generally listed as ±15 VDC and ±24 VDC. If the TCPS is not delivering, nothing else in the core will work correctly.

The "DC Input" in the name is literal: the board is fed with direct current, not AC. That 125 VDC comes from the TCPD power-distribution board in the <PD> core, and where a site only has AC available a <DACA> converter has to make the 125 VDC first. One TCPS serves each core, so a triple-redundant Mark V has independent supplies in <R>, <S> and <T>, with additional units in the <C> and I/O cores.

A Dead Core Is Not Always a Dead Supply

The most useful habit before ordering a replacement is to prove the board is genuinely at fault. A core that looks dead very frequently turns out to be missing its input rather than carrying a failed supply.

• Check the 125 VDC input at the board first. A lost source, a dropped <DACA> output, or an AC-only feed with no converter produces the same symptoms as a dead TCPS.
• Read the output rails at the silkscreened test points with a calibrated meter, or take the values off the DIAGC display. A meter that is out of calibration can send you chasing a nonexistent fault, or lead to mis-setting the +5 VDC rail and creating an intermittent one.
• When more than one core reports a supply problem simultaneously, look for a ground on the shared bus before assuming several boards failed together — one grounded device on a shared 24 VDC bus can drag the rail down across cores.

None of this means the TCPS never fails; it runs warm and is a genuine wear item. It simply means the input and the shared bus are cheaper to rule out than a board is to replace.

Where the TCPS Sits in the Power Distribution Path

The supply is one link in the Mark V power chain. Ahead of it is the TCPD board in the <PD> core, distributing the 125 VDC; behind it are the working boards of the core it feeds, including cards such as the TCDA digital I/O and the TCQA analog I/O. The GE Mark V DS200 Boards Explained guide sets out those relationships, and the GE Speedtronic Turbine Control Boards collection lists the broader catalog we support. Sites considering a platform change can read Mark V vs Mark VI: DS200 to IS200 for how the architecture evolved.

How the TCPS Part Number Reads

This unit is a DS200TCPSG1A, full number DS200TCPSG1AME. Reading across, DS200 is the Mark V series, TCPS is the DC-input power-supply function, G1 is the group — the TCPS is normally supplied as group 1 — and AME is the revision. Other revisions you may see, such as APE, ARE or AHC, are successive versions of the same board; match the one your panel was built with, or confirm supersession before fitting a different revision. The GE Speedtronic Part Number Decoder breaks down the format, and the number should be read from the board's silkscreen.

Information to Send With Your Request

• The full part number and revision (DS200TCPSG1AME).
• A photo of the label and silkscreen.
• Turbine model and Mark V architecture (Simplex or TMR).
• The core the supply serves.
• Quantity and required timing.

Get a Quote Within 24 Hours

This DS200TCPSG1AME is new surplus, supplied out of the box, cleaned and tested, with a one-year warranty. Send the details above using the Request a Quote button and we will respond within 24 hours with availability and lead time. We ship worldwide DDP and accept purchase orders.