Hi,

I need confirmation if below signals in MarkV are the Solenoid outputs and need Wet contacts? Below is extract from TC2KREPT:<pre>
QD1> DTBD 006 CO32NO 83B NO S83B LOG Base load indication - for cable remote
<QD1> DTBD 007 CO32C 83B NO S83B LOG Base load indication - for cable remote
<QD1> DTBD 008 CO32NC 83B NO S83B LOG Base load indication - for cable remote

<QD1> DTBD 009 CO33SO 83P NO S83P LOG Peak load indication - for cable remote
<QD1> DTBD 010 CO33NO 83P NO S83P LOG Peak load indication - for cable remote
<QD1> DTBD 011 CO33C 83P NO S83P LOG Peak load indication - for cable remote
<QD1> DTBD 012 CO33NC 83P NO S83P LOG Peak load indication - for cable remote

<QD1> DTBD 013 CO34SO 83PS NO S83PS LOG Presel load indication - for cable remote
<QD1> DTBD 014 CO34NO 83PS NO S83PS LOG Presel load indication - for cable remote
<QD1> DTBD 015 CO34C 83PS NO S83PS LOG Presel load indication - for cable remote
<QD1> DTBD 016 CO34NC 83PS NO S83PS LOG Presel load indication - for cable remote

NA <QD1> DTBD 017 CO35SO 94X1 C L94X1 LOG Reverse power
<QD1> DTBD 018 CO35NO 94X1 C L94X1 LOG Reverse power
<QD1> DTBD 019 CO35C 94X1 C L94X1 LOG Reverse power
<QD1> DTBD 020 CO35NC 94X1 C L94X1 LOG Reverse power

<QD1> DTBD 021 CO36SO 83SCI NO L83SCIX1 LOG Isochrone mode indication - for cable remote
<QD1> DTBD 022 CO36NO 83SCI NO L83SCIX1 LOG Isochrone mode indication - for cable remote
<QD1> DTBD 023 CO36C 83SCI NO L83SCIX1 LOG Isochrone mode indication - for cable remote
<QD1> DTBD 024 CO36NC 83SCI NO L83SCIX1 LOG Isochrone mode indication - for cable remote


<QD1> DTBC 037 CO10SO 4T NO S4T LOG TAC tripped - interface DCS
<QD1> DTBC 038 CO10NO 4T NO S4T LOG TAC tripped - interface DCS
<QD1> DTBC 039 CO10C 4T NO S4T LOG TAC tripped - interface DCS
<QD1> DTBC 040 CO10NC 4T NO S4T LOG TAC tripped - interface DCS

<QD1> DTBC 041 CO11SO 52LX NO S52LX LOG TAC synchronized - interface DCS
<QD1> DTBC 042 CO11NO 52LX NO S52LX LOG TAC synchronized - interface DCS
<QD1> DTBC 043 CO11C 52LX NO S52LX LOG TAC synchronized - interface DCS
<QD1> DTBC 044 CO11NC 52LX NO S52LX LOG TAC synchronized - interface DCS

<QD1> DTBC 045 CO12SO 94X NO S94X LOG Normal stop request recorded - interface DCS
<QD1> DTBC 046 CO12NO 94X NO S94X LOG Normal stop request recorded - interface DCS
<QD1> DTBC 047 CO12C 94X NO S94X LOG Normal stop request recorded - interface DCS
<QD1> DTBC 048 CO12NC 94X NO S94X LOG Normal stop request recorded - interface DCS

NA <QD1> DTBC 049 CO13SO 30BASE NO S30BASE LOG BASE indication - interface DCS
<QD1> DTBC 050 CO13NO 30BASE NO S30BASE LOG BASE indication - interface DCS
<QD1> DTBC 051 CO13C 30BASE NO S30BASE LOG BASE indication - interface DCS
NA <QD1> DTBC 052 CO13NC 30BASE NO S30BASE LOG BASE indication - interface DCS</pre>

 

Hi, this is pretty hard to do without being able to "draw" in control.com, and I've lost my work in two responses so far this morning. But, we shall endeavour to persevere....

You need to refer to the Signal Flow Diagrams in Appendix D of the 'Mark V Application Manual,' GEH-6195. I believe the discrete outputs (which refers to "contact outputs" or "relay outputs" and "solenoid outputs") are shown on Figure D-5 (for the DTBC I/O terminal board) and Figure D-6 for the DTBD I/O terminal board. The information you have posted is for the DTBD I/O terminal board (again, usually Figure D-6).

Approximately half of the "contact outputs" (discrete outputs) can be configured to be either relay outputs or solenoid outputs. The "configuration" is done by using the PX & MX jumpers on the DTBC or DTBD I/O terminal boards <b>AND</b> the placement of the field wires of the circuit terminated on the I/O terminal board.

Let's further define relay output and solenoid outputs. Relay outputs are simply discrete- or contact outputs which can switch power--power that is applied via the wires connected to the Mark V I/O terminal board from an external circuit. The power for the circuit connected to the Mark V I/O terminal board of a "relay output" DOES NOT come from the Mark V--it comes from the circuit which is connected to the Mark V I/O terminal board of that output (relay output). This is typically referred to as a "dry contact" output--the dry referring to the lack of power from the Mark V.

Mark V solenoid outputs provide 125 VDC power at the DTBC or DTBD I/O terminal board output terminals to power the circuits or devices terminated to those outputs. That's done by positioning the PX & MX jumpers for the particular outputs AND by connecting the circuit wires to the proper terminals. Most of the solenoids and solenoid-operated devices used on GE-design heavy duty gas turbine operate on 125 VDC, hence the reason for only providing 125 VDC output power (with one exception--for the ignitor (spark plug) outputs). This is sometimes referred to as a "wet contact" output--the "wet" referring to the power which is available at the Mark V I/O terminal board output screws if the PX & MX jumpers are in the proper positions.

The discrete outputs of the Mark V are c-form outputs, meaning there are NO (Normally Open) and NC (Normally Closed) terminals, with a C (Common) terminal to use for the second wire of the circuit for a relay output. If the discrete output is configured to use as a solenoid output, one would connect one wire of the field device or circuit to either the NO or NC terminal (usually the NO terminal) for the positive leg of the 125 VDC power from the Mark V, and the second wire to the SOL terminal of the output for the negative leg of the 125 VDC power from the Mark V.

Let's pick the first input in your list. CO32 (Contact Output 32), which is the second discrete output on the DTBD I/O terminal board--and it can be either a solenoid output, or a discrete output. DTBD-5 is the SOL terminal--which would be where the negative leg of the 125 VDC from the Mark V would be available for the circuit/device this output would be operating. DTBD-6 is the NO (Normally Open) terminal of the CO32 discrete output. DTBD-7 is the C (or Common) terminal of the CO32 discrete output. And DTBD-8 NC (Normally Closed) terminal of CO32 the discrete output.

The device shown connected to the discrete output terminals of the DTBD on Figure D-6 is a solenoid--it is terminated on the SOL and NC terminals of the discrete output. And, with jumpers P2 and M2 in place on the DTBD I/O terminal board negative 125 VDC would be present at DTBD-5 (the SOL terminal of CO32), and when the relay on the TCRA card in Loc. 5 of the discrete output module was energized the NO contacts of the relay would be closed, and positive 125 VDC would be present at DTBD-6 (the NO terminal of CO32).

From your information, CDB (Control Signal Database) signal S83B is assigned to <QD1> CO32. And the description for this discrete output is "Base load indication - for cable remote." This is an output that is usually used to tell another control system that Base Load mode is active in the Mark V. Usually, the other control system will provide the power for the circuit connected to this output; it may be 24 VDC, or 24 VAC, or 120 VAC. So, usually, this output is configured to be a "dry contact" output--because the power that is being switched by this discrete output is coming from outside the Mark V turbine control panel. (I have seen sites that used this output to energize an indicating light on a panel somewhere in the plant, and the light requires 125 VDC to illuminate, and sometimes the output was configured as a solenoid output by putting the PX & MX jumpers in place and connecting the indicating light wires to the SOL and NO terminals (DTBD-5 and DTBD-6) to provide the 125 VDC to the indicating light when Base Load was active in the Mark V CSP (Control Sequence Program). But, this is unusual; usually the other control system, including indicating lights, powers the circuit.)

In fact, most of the discrete outputs you have listed are <i>usually</i> just for indication purposes, and for circuits that are USUALLY NOT powered by the Mark V 125 VDC power supply. So, the wires for each circuit would <i>usually</i> be connected to the NO and C terminals of the respective discrete outputs, and not connected as solenoid outputs.

Hope this helps!