What the TCPS Feeds in a Mark V Panel

The DS200TCPS is the regulated supply that stands behind every board in a Mark V core. Fed from the panel's 125 VDC bus, it produces the low-voltage rails the core electronics use: the +5 VDC logic supply, set at the board with a potentiometer, plus the analog, RTD and servo rails commonly documented as ±15 VDC and ±24 VDC. Whatever the core does — processing, analog measurement, servo drive — runs on power that came through this board.

Its description says "DC Input" because the board is supplied with direct current: 125 VDC delivered by the TCPD power-distribution board in the <PD> core. It does not accept AC, so an AC-only site relies on a <DACA> converter to make the 125 VDC. The Mark V places one TCPS in each core, meaning a TMR panel has separate supplies for <R>, <S> and <T> as well as the <C> and I/O cores, so a supply problem is contained to a single core.

Check the 125 VDC Feed Before Condemning the Card

The most common way to waste money on a TCPS is to replace one that was never faulty. A core that appears unpowered is, more often than not, missing its input — so start there.

• Verify the 125 VDC input at the board itself. A tripped upstream source, a failed <DACA> converter, or an AC-only supply with no converter all imitate a dead TCPS.
• Measure the output rails at the board's silkscreened test points with a calibrated meter, or read them from the DIAGC display for that core. An uncalibrated meter can lead you to mis-set the +5 VDC rail and create an intermittent fault that looks like a failing board.
• When several cores alarm on the same rail at once, suspect a ground on the shared 24 VDC bus rather than simultaneous board failures, and trace the grounded device first.

The TCPS is nonetheless a genuine wear item that runs warm and can become audibly noisy as it ages, so real failures do occur. Confirming the input and the shared bus first is simply the fastest way to be sure the board is the actual problem.

How to Read DS200TCPSG1ARE

The label reads DS200TCPSG1A, with the full number DS200TCPSG1ARE. That is DS200 for the Mark V board series, TCPS for the DC-input power-supply function, G1 for the group — the supply is normally built as group 1 — and ARE for the revision. Since revision tails like ARE, AME, APE and AHC are successive versions of the same board, match the one your panel was commissioned with, or confirm that a later revision supersedes yours before you fit it. Use the GE Speedtronic Part Number Decoder to check the fields, and read the number from the board silkscreen.

The Cards That Depend on the TCPS

Everything in the core the TCPS serves depends on it, and its own input comes from the TCPD board in the <PD> core. The cards it powers sit alongside the familiar Mark V I/O — the TCDA digital I/O and the TCQA analog I/O among them. Our GE Mark V DS200 Boards Explained guide shows how the group fits together, and the GE Speedtronic Turbine Control Boards collection covers the wider range. If a modernization is on the table, Mark V vs Mark VI: DS200 to IS200 outlines how the platform evolved.

Details That Speed Up Your Quote

• The full part number and revision (DS200TCPSG1ARE).
• A photo of the board label and silkscreen.
• Turbine model and whether the Mark V is Simplex or TMR.
• The core the supply serves.
• Quantity and how urgent the need is.

Get Your Quote Started

This DS200TCPSG1ARE is new surplus in the original factory packaging, 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.