Posts from...Today, Thursday, October 30, 2014
from the Forum department...Instrument Learning Materials?
New instrument engineer, could use some help!
from the Power generation department...Generator and Capacitor Bank
Totally stumped by the recent brawl over utility of capacitor bank in power generation.
Some useful information. Take care G.Rajesh...
FF... Please play particular attention to Candl_Pete's excellent post. He was able to illustrate...
FF, further to my earlier post, see the following Control.Com thread: ...
FF, problem is clearer. Following is a summary, based on information provided to date: A)...
from the Operations department...Steam turbine shutdown
What is the proper sequence for shutting down a combined cycle plant? Gas turbine or Steam Turbine first?
By Caleb on 30 October, 2014 - 4:01 am -
Hey! At our 2x1 plant we have 2 GE MS7001FA's exhausting to HRSGs that provide steam to an...
this makes no sense to me! How do they maintain enough steam to operate the turbine? Do they close...
By raul on 27 October, 2014 - 2:30 pm -
I'm an combined cycle operator and We shutdown the steam turbine before the Gas turbine. the reason...
from the Forum department...Blockage in Impulse Lines/ Filling Glycol
What is the best practice when you have blockage in impulse lines for flow transmitter how can clear the blockage?
what is the best equipment to fill glycol in level dp cell in both H & L sides?
what is the best equipment to fill glycol in level dp cell in both H & L sides?
from the Maintenance department...Issue with a Siemens 331 AI card
Experiencing an issue with an output on an AI card. Have a valid analog signal from the field device to the remote I/O PLC, but nothing from there to the control PLC.
By Curt Wuollet on 29 October, 2014 - 11:58 pm -
Measure the voltage to ground at the AI terminals. It sounds to me like the voltage is outside what...
By Chris on 29 October, 2014 - 8:44 pm -
Hello David, Thank you very much for the response and I apologize for the lack of information...
You haven't told us what kind of signal is coming from the level transmitter (presumably 4-20mA),...
from the Instrumentation department...Why shield should be at one end in cabinets
When instrument shield connection to ground, why connect at one end of the cable, especially internal cables?
By Curt Wuollet on 29 October, 2014 - 11:46 pm -
You can do whatever you want with your shields:^). The idea behind grounding one end only is that...
Srbg, What you are describing is entirely possible--and would be correct as long as the shield...
Thanks for the info. I am particularly interested in why cannot we make our shield continuous...
from the Forum department...Grounding Current Transformers
Need for grounding of secondary terminal of current transformer.
Gautam... Q1: The ground-terminal protects endangerment of human life if there is a...
By Curt Wuollet on 29 October, 2014 - 11:06 pm -
It serves several purposes, one being safety in case of an insulation breakdown. Since the...
from the engineer department...Radar Level Transmitter in Fiber Board Factory
Is radar level transmitter suitable for fiber board factory?
from the Forum department...Useful Instruments for Locating Electrical Faults
Are there some useful technician instruments for finding faults in electrical equipment
By Curt Wuollet on 29 October, 2014 - 10:58 pm -
You can make some really good guesses with a voltmeter. If the ends show a low voltage there's a...
from the Solar department...Modbus Training Courses
Looking for Modbus training courses
I created a course on uDemy called Mastering Modbus RS485 Network Communication for persons wanting...
from the Forum department...RS485 to Analog Input Conversion
Is it possible to convert (multiple) readings being transmitted through RS-485 communication to analog signals?
Thank you Walt. I do agree with you, however the powers-that-be still requested for the research to...
Thank you Curt! This is exactly the kind of stuff I was looking for....
from the Forum department...SLC500 Communications with Unitronics PLC
Setting up communications between a Unitronics PLC and SLC 500 PLC
By Jeremy Pollard on 29 October, 2014 - 9:00 am -
I think the simplest thing to implement here would be Modbus. The Unitronics can be a Modbus master...
from the Thermal Engineering department...Thermal Efficiency Improvement of a Combined Cycle Power Plant
Thermal Efficiency Improvement of a Combined cycle power plant by absorbing excess Flue gas temperature without altering any design parameters.
from the ELECTRICAL/INSTRUMENTATION department...Why IRP Used for Interface Between DCS and MCC
Why is an IRP panel is used between DCS and MCC?
from the Engineering department...Cathodic Protection DC Cable and Instrument Cable in Same Tray
The consequence to run cathodic protection DC cable and instrument cable (most 24 VDC) cable in same cable tray.
from the Forum department...Changing SRV Valve setting
I need help to change the set point for SRV open position.
rwailikhalid, FPRG is a control signal database signal name for P2 Pressure Reference (Fuel...
where i can find FPRG?...
from the Forum department...Citect Modnet driver
MODBUS TCP I/O driver modnet not responding to input discrete tags, but is able to read all analog input register data and able to respond to output discrete tags.
By aizat on 28 October, 2014 - 8:06 pm -
Hi i use multiple modnet device for my I/O device. The problem is the output response...
from the Power Generation department...Gas Turbine control - Hardware Part Trip of L4
When Hardware causes the trip of L4
Neo, I'll try to answer your questions, but I'm not clear on at least one of them. Yes; you...
Very happy to see the detailed discussion. Go ahead for great success. Take care G. Rajesh ...
CSA: I read and reread your response,and it really helps! And thanks for your drawings. ...
from the control department...Sending a Signal from MKV to Emerson DCS Via MODBUS
I want to send a signal via MODBUS to Emerson DCS
CuriousOne, If I only had a nickel for every time I have heard that refrain I would be a very,...
By CuriousOne on 28 October, 2014 - 12:01 am -
It is a simple as changing a couple of text files and restarting interfaces....
from the Fire alarm department...Speaker Strobe for Class 2 Div 1 Rated Area
Explosion proof/dust proof equipment needs
from the LITTLE GRASSHOPPERS department...MODBUS Radio Network
How many radio receivers do I need in a MODBUS EIA-485 network using VERIS H8830?
Thank you Koen for your help. Where can I get hands on a document who explains how these radios...
Routing is automatic. All H8830 devices create one RS485 network so all devices on the RS485...
from the Instrumentation department...Mark V A6 state
Mark V <C> at A6 state after modify and download IO.ASS and IOCFG
Thanks Bob for your feedback. No we couldn't locate the card as when it was at A6 and found...
from the INSTRUMENT department...Grounding Problem in Siemens DCS
In DCS panel the resistance measured between power earth and signal earth vary from 24 ohm to 160 ohm in different panels.
My apologies, I see now that I misread your post. You should not have that much resistance...
You need to be specific not only with the resistance magnitudes you describe but also how you are...
> resistance between power earth and signal earth is varying from 40 ohm to 120 ohm. It...
from the Automation Safety department...AB or Siemens Equivalent Safety Product as Sick's Flexi-Loop
Is there any Allen Bradley or Siemens safety product that has similar modular capbilities as Sick's Flexi-Loop system?
By marionjlite on 28 October, 2014 - 2:01 am -
Looking forward to reading more. Great article. Much thanks again. Much obliged....
from the Forum department...Electric Motor Driven Actuator
Actuated valve in remote location where no instrument air availability.
what is the valve controlling/modulating? There are many options. Rexa has options that are all...
from the ModbusTCP department...PROSOFT MVI56-MNET Slave Response Time
PROSOFT MVI56-MNET communication response time and performance
By CH on 27 October, 2014 - 5:49 pm -
I just tested this with Modscan32 and the MNET unit was replying as fast as Modscan32 could request...
from the DLN combustor department...Humming in DLN combustor V94.3A
How to fix the humming in combustion chamber when Gas turbine is loading or unloading.
By gbruce on 27 October, 2014 - 5:25 pm -
Your GT should have low frequency humming (10-30Hz). If it is the case you should check if the...
from the Petroleum Refinery. department...Analog Input Cards for Programmable Logic Controller.
PLC card - High Channel density drawbacks.
By Ed Wilson on 27 October, 2014 - 3:58 pm -
Is the resolution the same on the 16 and 32? If so the 32 may react a little slower depending on...
from the I might be wrong but I doubt it. department...Thoughts on High Performance HMI
How to implement the ideas in the book "The High Performance HMI" without meddling in code layer?
By Arlen Jacobs on 27 October, 2014 - 2:45 pm -
The effort is worth it, if you have the right goals defined at the start. Easier training of new...
from the Protective Relaying department...Transformer Differential Relay Protection during Open-Phase
Transformer Differential Relay Protection during Open-Phase. Possibility of the relay to trip during line to ground fault or open conductor outside the zone of the differential scheme?
By Amrit Pandey on 27 October, 2014 - 2:27 pm -
Phil, I am emailing you my excel sheet and wiring diagrams. -Amrit...
Death is life's way of telling you you've been fired.
-- R. Geis
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