N
Why do we need to force L4_XTP during stroke checks of SRV/GCV when turbine at? is it because of L4 in false condition? and what does it mean L4_XTP as PPRO Q to P cross trip logic??
G
Greg Ponto
Take a real good look at GEH-6195, signal flow diagram D-59. The fuel gas trip solenoid actually takes 2 relay contacts to pick-up ETR1 2/3 and PTR1 2/3(assuming 2/3 means 2 out of 3 for TMR). "L4_XTP" picks-up ETR1 and "L20FG1X" picks-up PTR1. This is something good to keep in mind for future troubleshooting.
Greg Ponto
Lead Combustion Turbine Specialist
Elwood Energy
Greg Ponto
Lead Combustion Turbine Specialist
Elwood Energy
MODERATOR: Something terribly wrong happened with the previous post! Can you please replace that post with the one below? PLEASE?
Thanks!!!
NVK,
The description below presumes the signal name for the Gas Fuel Trip Solenoid output "relay" is L20FG1X. Some sites use L20FGX; some sites use L20FG1. Refer to thelogic/application code for the unit(s) at your site for the exact signal name for the "relay" which drives the Gas Fuel Trip Solenoid.<pre>
---------------------- -----------------------
Mark V PTBA | | Mark V PTBA
Mark VI TRPG | | Mark VI TREG
Mark VIe TRPG | | Mark VIe TREG
<R> <S> | /\ | <X> <Y>
L20FG1X L20FG1X | / \ | L4_XTP L4_XTP
-65 VDC ------| |-----| |------|-------------\ / \----------|-----=| |-----| |-------- +65 VDC
| | | \ / | | |
| <S> <T> | | \/ | | <Y> <Z> |
|L20FG1X L10FG1X | | 20FG-1 | | L4_XTP L4_XTP |
---| |-----| |---- | Gas Fuel | ----| |-----| |----
| | | Trip Solenoid | | |
| <R> <T> | | | | <X> <Z> |
|L20FG1X L20FG1X | | | | L4_XTP L4_XTP |
---| |-----| |---- | | ----| |-----| |----
| |
| |
Primary Trip Emergency Trip
Relays Relays
Driven by L20FG1X Driven by L4_XTP
(Typical Signal Name) Inverse of L4)</pre>
The answer to your question is that in order to get a full 125 VDC (nominal) across the Gas Fuel Trip solenoid, 20FG-1, and to get current to flow through the Gas Fuel Trip Solenoid BOTH the Primary Trip Relays (driven by L20FG1X from <Q>) AND the Emergency Trip Relays (driven by L4_XTP, which is the inverse of L4) must be closed to energize the solenoid, which allows Trip Oil Pressure to actuate the dump valve which allows high-pressure hydraulic oil to pass from the Stop-Ratio Valve servo-valve to the Stop-Ratio Valve hydraulic actuator.
The drawing above shows the two-out-of-three logic used by GE for a TMR Speedtronic turbine control panel for both the Primary- and Emergency Trip Relays, and the respective processors which drive each of the relays. Each of <R>, <S> and <T> has its own Primary Trip Relay, all driven by the same signal (L20FG1X). The Protective Processors (<X>, <Y> and <Z>) each has its own Emergency Trip Relay, all driven by the same signal (L4_XTP, which is the inverse of L4).
Some--but NOT all--Gas Control Valves also require the Gas Fuel Trip Solenoid to be energized to allow high-pressure Hydraulic Oil to pass from the Gas Control Valve servo-valve to the Gas Control Valve hydraulic actuator. But most OEM and packager TAs don't bother to look at the P&IDs to determine if Trip Oil is required for operation of the GCV and just force L20FG1X and L4_XTP for both stroking both valves, even if it's not required for the GCV. Many turbines also require 20TV-1 to be energized in order to establish Trip Oil pressure when trying to stroke the SRV.
Now, for the next two questions: Why is L4_XTP the inverse of L4? And why is it called the "cross-trip" relay? The Steam Turbine control group, when they were "persuaded" to start using the Mark V for steam turbine control and protection, insisted on an "energize to trip" relay/signal for the emergency protective function, and that it also be "tied to" (operate in conjunction with) the Master Protective signal, L4. In this way, the Emergency Trip Relays would operate (be energized) whenever the Primary Master Protective signal was de-energized, signifying the primary control processors had detected a condition that warranted a turbine trip to ensure voltage (and current) would be removed from the trip solenoid as necessary. The Mark V designers decided to incorporate the functionality requested by the Steam Turbine controls group into the gas turbine design.
And, of course, they did so with little or no documentation in any of the manuals, just to be consistent.
Finally, most of the OEM and packager TAs also force L20FL1X, L4_XTP and L20TV1X (for 20TV-1) when stroking and/or calibrating the Liquid Fuel Bypass Valve. Of course, this is totally unnecessary because Trip Oil is not required to operated the Liquid Fuel Bypass Valve, but since they never look at P&IDs and just ass-u-me the same things have to be done to stroke/calibrate the Liquid Fuel Bypass Valve they always force the Liquid Fuel Stop Valve Solenoid and the Cross-trip Relays--just to be consistent. Even though it's unnecessary. 20FL-1 generally has nothing to do with the Liquid Fuel Bypass Valve; it only allows high-pressure Hydraulic Oil to pass through to actuator of the Liquid Fuel Stop Valve, VS1-1, to open the Liquid Fuel Stop Valve.
Thanks!!!
NVK,
The description below presumes the signal name for the Gas Fuel Trip Solenoid output "relay" is L20FG1X. Some sites use L20FGX; some sites use L20FG1. Refer to thelogic/application code for the unit(s) at your site for the exact signal name for the "relay" which drives the Gas Fuel Trip Solenoid.<pre>
---------------------- -----------------------
Mark V PTBA | | Mark V PTBA
Mark VI TRPG | | Mark VI TREG
Mark VIe TRPG | | Mark VIe TREG
<R> <S> | /\ | <X> <Y>
L20FG1X L20FG1X | / \ | L4_XTP L4_XTP
-65 VDC ------| |-----| |------|-------------\ / \----------|-----=| |-----| |-------- +65 VDC
| | | \ / | | |
| <S> <T> | | \/ | | <Y> <Z> |
|L20FG1X L10FG1X | | 20FG-1 | | L4_XTP L4_XTP |
---| |-----| |---- | Gas Fuel | ----| |-----| |----
| | | Trip Solenoid | | |
| <R> <T> | | | | <X> <Z> |
|L20FG1X L20FG1X | | | | L4_XTP L4_XTP |
---| |-----| |---- | | ----| |-----| |----
| |
| |
Primary Trip Emergency Trip
Relays Relays
Driven by L20FG1X Driven by L4_XTP
(Typical Signal Name) Inverse of L4)</pre>
The answer to your question is that in order to get a full 125 VDC (nominal) across the Gas Fuel Trip solenoid, 20FG-1, and to get current to flow through the Gas Fuel Trip Solenoid BOTH the Primary Trip Relays (driven by L20FG1X from <Q>) AND the Emergency Trip Relays (driven by L4_XTP, which is the inverse of L4) must be closed to energize the solenoid, which allows Trip Oil Pressure to actuate the dump valve which allows high-pressure hydraulic oil to pass from the Stop-Ratio Valve servo-valve to the Stop-Ratio Valve hydraulic actuator.
The drawing above shows the two-out-of-three logic used by GE for a TMR Speedtronic turbine control panel for both the Primary- and Emergency Trip Relays, and the respective processors which drive each of the relays. Each of <R>, <S> and <T> has its own Primary Trip Relay, all driven by the same signal (L20FG1X). The Protective Processors (<X>, <Y> and <Z>) each has its own Emergency Trip Relay, all driven by the same signal (L4_XTP, which is the inverse of L4).
Some--but NOT all--Gas Control Valves also require the Gas Fuel Trip Solenoid to be energized to allow high-pressure Hydraulic Oil to pass from the Gas Control Valve servo-valve to the Gas Control Valve hydraulic actuator. But most OEM and packager TAs don't bother to look at the P&IDs to determine if Trip Oil is required for operation of the GCV and just force L20FG1X and L4_XTP for both stroking both valves, even if it's not required for the GCV. Many turbines also require 20TV-1 to be energized in order to establish Trip Oil pressure when trying to stroke the SRV.
Now, for the next two questions: Why is L4_XTP the inverse of L4? And why is it called the "cross-trip" relay? The Steam Turbine control group, when they were "persuaded" to start using the Mark V for steam turbine control and protection, insisted on an "energize to trip" relay/signal for the emergency protective function, and that it also be "tied to" (operate in conjunction with) the Master Protective signal, L4. In this way, the Emergency Trip Relays would operate (be energized) whenever the Primary Master Protective signal was de-energized, signifying the primary control processors had detected a condition that warranted a turbine trip to ensure voltage (and current) would be removed from the trip solenoid as necessary. The Mark V designers decided to incorporate the functionality requested by the Steam Turbine controls group into the gas turbine design.
And, of course, they did so with little or no documentation in any of the manuals, just to be consistent.
Finally, most of the OEM and packager TAs also force L20FL1X, L4_XTP and L20TV1X (for 20TV-1) when stroking and/or calibrating the Liquid Fuel Bypass Valve. Of course, this is totally unnecessary because Trip Oil is not required to operated the Liquid Fuel Bypass Valve, but since they never look at P&IDs and just ass-u-me the same things have to be done to stroke/calibrate the Liquid Fuel Bypass Valve they always force the Liquid Fuel Stop Valve Solenoid and the Cross-trip Relays--just to be consistent. Even though it's unnecessary. 20FL-1 generally has nothing to do with the Liquid Fuel Bypass Valve; it only allows high-pressure Hydraulic Oil to pass through to actuator of the Liquid Fuel Stop Valve, VS1-1, to open the Liquid Fuel Stop Valve.
MODERATOR: Something terribly wrong happened with the previous post! Can you please replace that post with the one below? PLEASE?
Thanks!!!
NVK,
The description below presumes the signal name for the Gas Fuel Trip Solenoid output "relay" is L20FG1X. Some sites use L20FGX; some sites use L20FG1. Refer to thelogic/application code for the unit(s) at your site for the exact signal name for the "relay" which drives the Gas Fuel Trip Solenoid.<pre>
---------------------- -----------------------
Mark V PTBA | | Mark V PTBA
Mark VI TRPG | | Mark VI TREG
Mark VIe TRPG | | Mark VIe TREG
| /\ |
L20FG1X L20FG1X | / \ | L4_XTP L4_XTP
-65 VDC ------| |-----| |------|-------------\ / \----------|-----=| |-----| |-------- +65 VDC
| | | \ / | | |
| | | \/ | | |
|L20FG1X L10FG1X | | 20FG-1 | | L4_XTP L4_XTP |
---| |-----| |---- | Gas Fuel | ----| |-----| |----
| | | Trip Solenoid | | |
| | | | | |
|L20FG1X L20FG1X | | | | L4_XTP L4_XTP |
---| |-----| |---- | | ----| |-----| |----
| |
| |
Primary Trip Emergency Trip
Relays Relays
Driven by L20FG1X Driven by L4_XTP
(Typical Signal Name) Inverse of L4)</pre>
The answer to your question is that in order to get a full 125 VDC (nominal) across the Gas Fuel Trip solenoid, 20FG-1, and to get current to flow through the Gas Fuel Trip Solenoid BOTH the Primary Trip Relays (driven by L20FG1X from ) AND the Emergency Trip Relays (driven by L4_XTP, which is the inverse of L4) must be closed to energize the solenoid, which allows Trip Oil Pressure to actuate the dump valve which allows high-pressure hydraulic oil to pass from the Stop-Ratio Valve servo-valve to the Stop-Ratio Valve hydraulic actuator.
The drawing above shows the two-out-of-three logic used by GE for a TMR Speedtronic turbine control panel for both the Primary- and Emergency Trip Relays, and the respective processors which drive each of the relays. Each of , and has its own Primary Trip Relay, all driven by the same signal (L20FG1X). The Protective Processors (, and ) each has its own Emergency Trip Relay, all driven by the same signal (L4_XTP, which is the inverse of L4).
Some--but NOT all--Gas Control Valves also require the Gas Fuel Trip Solenoid to be energized to allow high-pressure Hydraulic Oil to pass from the Gas Control Valve servo-valve to the Gas Control Valve hydraulic actuator. But most OEM and packager TAs don't bother to look at the P&IDs to determine if Trip Oil is required for operation of the GCV and just force L20FG1X and L4_XTP for both stroking both valves, even if it's not required for the GCV. Many turbines also require 20TV-1 to be energized in order to establish Trip Oil pressure when trying to stroke the SRV.
Now, for the next two questions: Why is L4_XTP the inverse of L4? And why is it called the "cross-trip" relay? The Steam Turbine control group, when they were "persuaded" to start using the Mark V for steam turbine control and protection, insisted on an "energize to trip" relay/signal for the emergency protective function, and that it also be "tied to" (operate in conjunction with) the Master Protective signal, L4. In this way, the Emergency Trip Relays would operate (be energized) whenever the Primary Master Protective signal was de-energized, signifying the primary control processors had detected a condition that warranted a turbine trip to ensure voltage (and current) would be removed from the trip solenoid as necessary. The Mark V designers decided to incorporate the functionality requested by the Steam Turbine controls group into the gas turbine design.
And, of course, they did so with little or no documentation in any of the manuals, just to be consistent.
Finally, most of the OEM and packager TAs also force L20FL1X, L4_XTP and L20TV1X (for 20TV-1) when stroking and/or calibrating the Liquid Fuel Bypass Valve. Of course, this is totally unnecessary because Trip Oil is not required to operated the Liquid Fuel Bypass Valve, but since they never look at P&IDs and just ass-u-me the same things have to be done to stroke/calibrate the Liquid Fuel Bypass Valve they always force the Liquid Fuel Stop Valve Solenoid and the Cross-trip Relays--just to be consistent. Even though it's unnecessary. 20FL-1 generally has nothing to do with the Liquid Fuel Bypass Valve; it only allows high-pressure Hydraulic Oil to pass through to actuator of the Liquid Fuel Stop Valve, VS1-1, to open the Liquid Fuel Stop Valve.
Thanks!!!
NVK,
The description below presumes the signal name for the Gas Fuel Trip Solenoid output "relay" is L20FG1X. Some sites use L20FGX; some sites use L20FG1. Refer to thelogic/application code for the unit(s) at your site for the exact signal name for the "relay" which drives the Gas Fuel Trip Solenoid.<pre>
---------------------- -----------------------
Mark V PTBA | | Mark V PTBA
Mark VI TRPG | | Mark VI TREG
Mark VIe TRPG | | Mark VIe TREG
| /\ |
L20FG1X L20FG1X | / \ | L4_XTP L4_XTP
-65 VDC ------| |-----| |------|-------------\ / \----------|-----=| |-----| |-------- +65 VDC
| | | \ / | | |
| | | \/ | | |
|L20FG1X L10FG1X | | 20FG-1 | | L4_XTP L4_XTP |
---| |-----| |---- | Gas Fuel | ----| |-----| |----
| | | Trip Solenoid | | |
| | | | | |
|L20FG1X L20FG1X | | | | L4_XTP L4_XTP |
---| |-----| |---- | | ----| |-----| |----
| |
| |
Primary Trip Emergency Trip
Relays Relays
Driven by L20FG1X Driven by L4_XTP
(Typical Signal Name) Inverse of L4)</pre>
The answer to your question is that in order to get a full 125 VDC (nominal) across the Gas Fuel Trip solenoid, 20FG-1, and to get current to flow through the Gas Fuel Trip Solenoid BOTH the Primary Trip Relays (driven by L20FG1X from ) AND the Emergency Trip Relays (driven by L4_XTP, which is the inverse of L4) must be closed to energize the solenoid, which allows Trip Oil Pressure to actuate the dump valve which allows high-pressure hydraulic oil to pass from the Stop-Ratio Valve servo-valve to the Stop-Ratio Valve hydraulic actuator.
The drawing above shows the two-out-of-three logic used by GE for a TMR Speedtronic turbine control panel for both the Primary- and Emergency Trip Relays, and the respective processors which drive each of the relays. Each of , and has its own Primary Trip Relay, all driven by the same signal (L20FG1X). The Protective Processors (, and ) each has its own Emergency Trip Relay, all driven by the same signal (L4_XTP, which is the inverse of L4).
Some--but NOT all--Gas Control Valves also require the Gas Fuel Trip Solenoid to be energized to allow high-pressure Hydraulic Oil to pass from the Gas Control Valve servo-valve to the Gas Control Valve hydraulic actuator. But most OEM and packager TAs don't bother to look at the P&IDs to determine if Trip Oil is required for operation of the GCV and just force L20FG1X and L4_XTP for both stroking both valves, even if it's not required for the GCV. Many turbines also require 20TV-1 to be energized in order to establish Trip Oil pressure when trying to stroke the SRV.
Now, for the next two questions: Why is L4_XTP the inverse of L4? And why is it called the "cross-trip" relay? The Steam Turbine control group, when they were "persuaded" to start using the Mark V for steam turbine control and protection, insisted on an "energize to trip" relay/signal for the emergency protective function, and that it also be "tied to" (operate in conjunction with) the Master Protective signal, L4. In this way, the Emergency Trip Relays would operate (be energized) whenever the Primary Master Protective signal was de-energized, signifying the primary control processors had detected a condition that warranted a turbine trip to ensure voltage (and current) would be removed from the trip solenoid as necessary. The Mark V designers decided to incorporate the functionality requested by the Steam Turbine controls group into the gas turbine design.
And, of course, they did so with little or no documentation in any of the manuals, just to be consistent.
Finally, most of the OEM and packager TAs also force L20FL1X, L4_XTP and L20TV1X (for 20TV-1) when stroking and/or calibrating the Liquid Fuel Bypass Valve. Of course, this is totally unnecessary because Trip Oil is not required to operated the Liquid Fuel Bypass Valve, but since they never look at P&IDs and just ass-u-me the same things have to be done to stroke/calibrate the Liquid Fuel Bypass Valve they always force the Liquid Fuel Stop Valve Solenoid and the Cross-trip Relays--just to be consistent. Even though it's unnecessary. 20FL-1 generally has nothing to do with the Liquid Fuel Bypass Valve; it only allows high-pressure Hydraulic Oil to pass through to actuator of the Liquid Fuel Stop Valve, VS1-1, to open the Liquid Fuel Stop Valve.
>MODERATOR: I wasn't aware of a character-per-line limit. Can you please post the "new" sketch below in place of the other(s)?
Thanks!
<pre>
--------------------- -----------------------
Mark V PTBA | | Mark V PTBA
Mark VI TRPG | | Mark VI TREG
Mark VIe TRPG | | Mark VIe TREG
| |
<R> <S> | /\ | <X> <Y>
L20FG1X L20FG1X | / \ | L4_XTP L4_XTP
-65 VDC-----| |-----| |-----|---\ / \---|-----| |-----| |-----+65 VDC
| | | \ / | | |
| <S> <T> | | \/ | | <Y> <Z> |
|L20FG1X L10FG1X| | 20FG-1 | | L4_XTP L4_XTP|
---| |-----| |--- | Gas Fuel | ---| |-----| |---
| | | Trip Solenoid | | |
| <R> <T> | | | | <X> <Z> |
|L20FG1X L20FG1X| | | | L4_XTP L4_XTP|
---| |-----| |--- | | ---| |-----| |---
| |
| |
Primary Trip | | Emergency Trip
Relays | | Relays
Driven by L20FG1X | | Driven by L4_XTP
( Typical Signal Name)| | (Inverse of L4)</pre>
Thanks!
<pre>
--------------------- -----------------------
Mark V PTBA | | Mark V PTBA
Mark VI TRPG | | Mark VI TREG
Mark VIe TRPG | | Mark VIe TREG
| |
<R> <S> | /\ | <X> <Y>
L20FG1X L20FG1X | / \ | L4_XTP L4_XTP
-65 VDC-----| |-----| |-----|---\ / \---|-----| |-----| |-----+65 VDC
| | | \ / | | |
| <S> <T> | | \/ | | <Y> <Z> |
|L20FG1X L10FG1X| | 20FG-1 | | L4_XTP L4_XTP|
---| |-----| |--- | Gas Fuel | ---| |-----| |---
| | | Trip Solenoid | | |
| <R> <T> | | | | <X> <Z> |
|L20FG1X L20FG1X| | | | L4_XTP L4_XTP|
---| |-----| |--- | | ---| |-----| |---
| |
| |
Primary Trip | | Emergency Trip
Relays | | Relays
Driven by L20FG1X | | Driven by L4_XTP
( Typical Signal Name)| | (Inverse of L4)</pre>
