Keith, Thanks for the great reply and my apologies for not performing a thorough search before posting this.
Bill, Yes, that was my concern when running the lead/lag configuration, that if they were not running at the same speed, he system might become unstable. I will run them at the same...
I have a client that wishes to run a pressure control loop using two identical pumps in parallel. The pumps will run on VFDs and the system will not have automatic isolation valves for the pumps.
The pumps will feed a cooling loop to several pieces of equipment that will be switched on and off...
Thanks for the post.
Good to know this is a 2S1W motor. I know how to control this type of motor in the "traditional" sense using three contactors. The motor isn't run with an enclosed starter or an MCC, it's a starter built into a control cabinet as part of a control system, so there is no...
I am looking for some advice on an application I am working on. I am a controls engineer, but I do not know much about application and selection of VFDs and line/load reactors.
I have a system I am working on upgrading. There is a 75hp blower motor that is a two speed two winding style. With the...
I have an application where a transistor output on a GE PLC is used to trigger a solid state interposing relay. The could voltage on my relay is 120VAC, and the PLC card is rated for 120 as well. It seems as though the leakage through the transistor is enough to energize my interposing relay. I...
Using Step-7, is there an easy way to connect to a Siemsns S7-300 and create a backup of all blocks and data?
Essentially I would like to take an as-found backup of an existing installation.
Thanks in advance,
Jay
I am integrating a proprietary controller into a system that uses Modbus TCP. I have discovered that this controller does not have Modbus function code 4 implemented, and therefore I can only use it to read holding registers. Anything stored in an input register is inaccessible. My slave device...
Electrical/Industrial controls
40 hrs per week when I'm in the office, 50-70 when I'm on the road. I don't get paid overtime, and only get to bank time when I work on a weekend. However we are pretty flexible here, officially on paper I need to work my 40, but if I come back off a 60 hour 4 day...
This sounds like 2 different problems to me. The pump failure and the pressure control can be handled separately.
As for the PI loop, are you stuck with the Click PLC? There are plenty of low cost PLCs with built in PID functions. The link is broken, si I can't say wether that would work or...
As catserveng said, it's under the Toole menu, then Compare...
You simply browse your disk for the two projects, or upload a project from a connected PLC.
ScottI2R, I completely agree, but if one of the programs is pulled off the PLC, with AB all of that information is lost.
In my opinion, you will never have enough reference material, and you will never be able to answer every question off the top of your head.
I am also somewhat new to the field, although I have nearly 10 years as a control systems engineer, and a few years as an industrial electrician apprentice...
The main NFPA code which I work with was revised for 2011, and there were a few major changes. I obviously have no problem complying with these changes, but I wonder when the code officially takes effect.
In Canada, our national electrical code gets revised every 4 years, however it doesn't get...
Has anyone sucessfully integrated an Allen Bradley SLC5/04 as a modbus slave using the com ports on the processor?
I am doing a retrofit on a system and there isn't any space left in the chassis. I want to avoid adding an expansion chassis and going with the Prosoft module if I can.
Thanks in...
With a lot of splashing and sloshing around I would suggest using a pressure transducer, either hanging in the tank near the bottom, or insterted near the bottom of the tank on a port or flange. There are hundreds of pressure sensors with 4-20mA outputs 1 psi is 27" of head with water...
