The DS200TCRA Group 2 Relay Output Board

This board is the group 2 build of the GE Speedtronic Mark V relay output card, DS200TCRAG2A. Like the group 1 version, it provides the panel's bank of electromechanical plug-in relays — up to thirty, K1 through K30 — that switch solenoids, contactors and permissive contacts on command from the turbine control. It is the layer of the Mark V that physically opens and closes the field circuits the controller calls for.

The relay board is part of the Mark V digital I/O, not the <R>, <S>, <T> or <C> processor cores. Within a digital I/O core it is paired with the TCDA digital I/O board that drives its coils, typically two TCRA boards to a core, and its contacts terminate on the DTBC and DTBD terminal boards. There is no programmable content on the card: whether an output is a dry contact or a wetted solenoid feed is decided by terminal-board jumpers, so the TCRA is fixed-function hardware.

Check the Logic Side First

When an output stops working, the relay board is the visible suspect but often not the guilty one. On the Mark V the TCDA energizes each relay by sinking one leg of its coil to common while the other leg sits at a fixed voltage, which means the driver and the interconnect can produce exactly the same dead-output symptom as a failed relay.

• Start at the TCDA: if the command is never registered there, the fault is upstream and no relay board will resolve it.
• If the TCDA shows the command but the contact does not move, the relay, the TCRA, or the ribbon cable is at fault; a plug-disconnected alarm points at the ribbon.
• Check the field last but never skip it — a shorted 125 VDC solenoid can burn a relay and the terminal-board traces, and will damage a new card if the short is still there.

Because the relays are mechanical, they wear and are commonly replaced individually, while an entire board usually fails only after a voltage surge, a battery ground, or a downstream short. Diagnosing to that level before ordering keeps a good card from being swapped needlessly.

Why the Group Number Matters on This Board

This is the point to pay attention to on a group 2 card. The number reads DS200TCRAG2A, with the full revision as DS200TCRAG2ABC: DS200 is the Mark V series, TCRA is the relay-output function, G2 is the build group, and ABC is the revision. The group designator is not cosmetic — a group 1 (DS200TCRAG1A) and a group 2 (DS200TCRAG2A) are separate builds, and you should not assume one drops in for the other. Order to the group your panel was engineered around, and confirm any supersession before substituting. The GE Speedtronic Part Number Decoder lays out the fields, and the group and revision should always be read from the board itself.

Companion Cards in the Digital I/O Core

A group 2 TCRA works within the same Mark V I/O family as any other: driven by the TCDA, terminated on the DTBC and DTBD boards, accompanied by the TCQA analog I/O and powered through the TCPS. Our GE Mark V DS200 Boards Explained guide shows how the cards interconnect, and the GE Speedtronic Turbine Control Boards collection lists the wider range we support. Sites evaluating the next platform can consult Mark V vs Mark VI: DS200 to IS200.

What to Send Us for a Quote

• The complete part number and revision (DS200TCRAG2ABC), read off the board.
• A photo of the label and silkscreen, which confirms the group and revision.
• Turbine model and whether the Mark V is Simplex or TMR.
• The serving core and the revisions in any paired cores.
• Quantity and required timing.

Request a Quote for the G2 Board

This DS200TCRAG2ABC is a used, cleaned and tested board with a one-year warranty. Send the details above through the Request a Quote button and we will reply within 24 hours with availability and lead time. We ship worldwide DDP and accept purchase orders.