Wireless pump controls?

[lmm600]

I posted this question under water distribution and have not got a response yet, so I'll try it here. I would like some information on reliability and ease of use for a wireless pump control between a water tank and pumphouse. The small municipal communication system now is hardwired underground. Would like to update but I would like some more info, especially on reliability. Or maybe certain equipment to stay away from?

 

[waross]

Remember;
"If it ain't broke, don't fix it!"
respectfully

 

[davidbeach]

What are you trying to accomplish that the present system can't do? Change for the sake of change is not a good policy.

 

[lmm600]

It has a 12 pair direct burial cable that has seen better days. I've been told its alot cheaper to go wireless than to replace the buried cable. And it actually is broken. Every time I splice wires it basically takes about a week for another break to occur. This is a very small town that does not have the resources (tools) to repair let alone find the faults.Basically my bosses have said enough.

 

[ScottyUK]

Redundant ethernet in a ring configuration is probably the best way to go. You should be able to do this with wireless ethernet, although I have never tried to set up a wireless ring. The switched ring topology is effective with fibre or copper links. You will need to maintain the protective functions locally - I would not trust a comms link for safety-critical functions.

What signals are you trying to transfer between locations?


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Sometimes I only open my mouth to swap feet...

 

[danw2]

I'm aware of a cement producer who's been running wireless comm between his pump house complex and the control room over a distance of about 500m for a couple years now with no reported drop out.

He paid extra for high gain antennas at each end to ensure a very high fade margin.

They have a spare transmitter, receiver, and lightning arrestor installed as back-up. He (manually) switches them over during an annual outage.

He uses the 1 watt, license-free, industrial I/O wireless from Phoenix Contact.

It's like replacing wires. Dry contact input at the transmitter comes out as dry contact at the receiver.
4-20mA input comes out as 4-20mA.

Dan

 

[VEBill]

Many of the municipal infrastructure around these parts (Halifax, NS) have UHF Yagi antennas poking out from the underground water works. These facilities most often are sewer pumping stations. Wireless seems to be standard around here for that purpose.

 

[mls1]

I integrated a system with nine remote wells and three reservoirs in a similar situation. We replaced the copper wire which was prone to failure due to lightening, rodents, trees, etc. with Elpro spread spectrum wireless telemetry devices. Five years into it there have been no problems. It was easy to install and has worked exceptionally well.

One piece of advice if you are thinking about wireless. There is no substitute for a good radio path survey (unless you have completely clear line of site). We had several obstructions but none were a problem. We had to use one Yagi antenna but all other installations us omni antennas with so-so gain. In addition to doing a topographic map study we performed field testing on all links before installation.

In our particular installation we used a Modbus base radio that received the telemetry from the field radios and stored the data in a Modbus registry. A PLC then read the register and made the data accessible to the SCADA network.

 

[pooslinger]

Phoenix contact makes a good radio set and so dose Dataradio. I have been running Phoenix radios for about 4 years and no problems. I am transmitting rs-232. Cost savings from the phone line charges makes these things pay for themselves. In did my own distance checks. Buy a set, hook them to a 24v ps and have fun.

 

[lmm600]

Sounds like reliability may not be a issue. This would be supposedly a low wattage setup. Site survey should be done in a few days. One of the systems that has been mentioned is from Banner. Thanks everyone for the opinions and info.

 

[peebee]

I'll second pooslinger's recommendation for Phoenix Contact.

http://www.phoenixcon.com/wireless/

They offer several cool products, ranging from a "cordless wire" or some such for discrete contacts and 4-20 signals, to wireless transmission of digital signals. Depending on the antenna selected, they can go something like 2 miles as I recall. I believe I heard that their wireless controls are used for the traffic signals on the Brooklyn Bridge (although it's possible I'm confusing them with another vendor). I used their controls exactly one time, for a rather critical (high-profile, not high-cost nor life-safety) installation, it's been in operation for several years now with no problems to my knowledge. We chose Phoenix over other alternates such as cell phone and telephone land line, and have been very happy with that decision to date.

 

[peebee]

Ha, I found my 2003 Eng-Tips thread asking for help on selecting a wireless system for the project I just mentioned, here's that thread:

http://eng-tips.com/viewthread.cfm?qid=44906&page=3

The omnex controls mentioned in that thread are actually made by Phoenix.

 

[peebee]

PS -- we specified a 3rd-party RF site survey on that project. Based on that experience, I'd still recommend an RF site survey for any RF project.

But, with hindsight, I might have deleted the "3rd-party" requirement -- I think Phoenix would have done a better job than the 3rd-party guy we got in there. Among other issues we had, we had specified that his reports indicate the exact antenna locations, but neither the contractor nor us design consultants ever received that documentation.

Maybe you could find someone better though. Good luck.

At the end of the day, none of this RF site survey stuff really mattered, they just stuck the antennas in a place that seemed to work. It would have made us all feel much better at the time, though.