Missing something

I showed up at a service call today, for a customer who I could barely understand. He spoke with a thick accent, though I'm not sure from where. He showed me his system with agitated urgency and frustration.

It was a tower of some sort, and the best I could understand, it was supposed to blow air and pump water at the same time. Careful inspection quickly revealed the problem. Someone had OBVIOUSLY stolen the entire control panel, not surprising since it was located in a remote area with absolutely no security system whatsoever.

It was eerie actually. The man seemed to be insisting that the reciprocating pump ran at different speeds, but I couldn't find a HINT of a VFD. He kept pointing to the fin sticking out behind the blades and saying something about wind direction, but there was no resolver. It was very important to him that the pump ran faster when the fan on top turned faster, and slower when the fan tuned slower. I think it's to keep the cows cool while they drink.

I was about halfway through sketching out a
resolver/PLC/inverter/motor circuit when it occurred to me that I'd better check with the gurus here before I bite off more than I can chew.

My question is this: Is it okay to bypass the E-stop before I connect both non-inverter duty motors to the same single phase VFD with only one conduit across a field that is about 2000 feet from the corner grounded delta 2 phase power service? Or should I just cut the big red lock off of the disconnect, slam it on, and see what happens?

Stationmaster

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Give me until April 2 to respond to this. My leg has this funny pull feeling in it (tensile stress??). I need to see my orthopedic surgeon tomorrow I think.

Dan Bentler

Sounds like you need a new plc - do you want japanese or western?
Not sure how to do this?
Just say what you need and somebody here will write the program for you!

Be very careful with using 2 phase VFD's on ungrounded systems...I would rewire it to a four phase grounded configuration and tie the ground down to the tower at each corner.

BTW, are the motors TEFC or ODP??

David:site:

I have seen this before and it is a well-known system for bringing water from underground resources to surface.

It works by that the fan induces air turbulence in the surrounding area where there is a known underground water reserve.
The turbulence causes a slight decrease in barometric pressure, which inturn means that the water will be driven to the surface.
The increase in moisture levels at the surface then causes a drop in surrounding air temperature (by the well-known moisture evaporation effect). This in turn again causes even more barometic prssure drop, and so forth.
The fan is driven by the piston that is cleverly installed in the pipe through which the underground water must pass.

All in all one should not think it can work this way, but seing one in action should be proof enough.

S& m corp may be able to help...

Hi Stationmaster,

There is a division of :site:that may be able to help you with this project.

We formed S & M [Smoke and Mirrors Corp LLC Ltd] a few years ago to tackle tough engineering projects by the brute force method of throwing the full, collective mental resources of the members of :site: at a problem. We have had some major breakthroughs over the years and would be happy to assist you with this most perplexing project.

As Head Libations Director, I hereby order the first round to be consumed and the deliberations to begin on S & M's latest project.

David:site::site::site:

"Surely" your not serious.

Stationmaster said:

My question is this: Is it okay to bypass the E-stop before I connect both non-inverter duty motors to the same single phase VFD with only one conduit across a field that is about 2000 feet from the corner grounded delta 2 phase power service? Or should I just cut the big red lock off of the disconnect, slam it on, and see what happens?

Stationmaster

Click to expand...

Cut
Slam
Enjoy

I think that David is onto something here. Lots of commitees and long hours spent at the "special" boardroom. I am absolutely possitive that a workable solution can be achieved.

All in favor of convirging on Stationmaster's job site raise their glass..er, hand.

David

maybe this explains the thick accent ...

markie said:

Sounds like you need a new plc - do you want japanese or western?
Not sure how to do this?
Just say what you need and somebody here will write the program for you!

Click to expand...

How PERCEPTIVE! That was going to be my next question: Could someone please suggest all the components I'll need, draw a schematic, and post a sample program? Maybe 2 or 3 so I can choose the one I like best. I'll ALSO need a pirated copy of the PLC programming application, complete with key code if it's not too much trouble, just in case I have to tweak the ladder.

Stationmaster

Everything you need to build the control system you can purchase here. http://automationpipedreams.com/

They have the best plc's by far.

My glass is already in position next to my PC. As soon as the beer pours in to it from the internet connection, I'll be on my way to deliver the hardware. Unfortunately because of the sheer size of it all, I'll have to fax it all, the internet cable is simply too small to push it all through (especially since it is already occupied for delivering the necessary fuel... er beer to get me going).

S&M for ever!!!

Kind regards,