After reviewing the attached sketch, I believe that the depicted placement of the irrigation controller would be the best option available in order to minimize the possibility of EMI (Electromagnetic Interference) or EMP (Electromagnetic Pulses) from interfering with the controllers’ programmed functions, its ability to accurately measure flow and maintain reliable communication. As discussed, placement too near any equipment that generates a magnetic field (i.e. transformers) will induce voltages as the magnetic field passes through a circuit boards traces, integrated circuits and wiring. The controller could interpret these induced voltages as programming instructions which could lead to spontaneous activation of zone valves, false program starts, communication interference with the central computer and ultimately, early demise of its electronic circuitry. I believe that you may have received information stating that a distance of 5 - 6 feet would be sufficient. Though this may be true under certain conditions, each application has to be reviewed on an individual basis. My experience over the past 29 years under actual field conditions, as apposed to controlled testing facility results, has proven that a minimum distance of 15 – 20 feet from any device that generates powerful magnetic fields is vital to the integrity of the controllers’ service life and reliability of operation. Noted on your sketch is a smaller single phase transformer that is within the 15 – 20 foot minimum recommended distance. Due to the smaller load demand that is likely from this transformer, its distance from the controller would sufficient and no interference is expected. Please note that any placement be done with future service in mind and that there is sufficient clearance for the lid and service door of the pedestal to open without structural interference. Should you have any questions related to the above information or just in general, please don’t hesitate to contact me. Thank you. Ray Schram Technical Service Specialist John Deere Green Tech LI 2750 214-347-3628 rschram@johndeeregreentech.com rschramceu@gmail.com ________________________________ From: Stuart Roosth [mailto:siroosth@gmail.com] Sent: Tuesday, June 01, 2010 5:41 PM To: Jules Roberts; Jared Powell; Tanner Whitson; Rodger Harrison; Tom Gorney; Juan Sanford; Paige Close Cc: Joel Massey; Jerry Fry; Karen.Eastman@oncor.com; Ashley Frosell; rlee@addisontx.gov; cbarnett@addisontx.gov; bgraham@addisontx.gov; lchandler@addisontx.gov; Schram, Ray Subject: Re: electrical service yard adjacent to tower near Vitruvian Way. Please review attachment and respond with an approval or any comments as soon as possible. After several conversations with a number of people I think we may be close to a decision. Please see the attached sketch of the transformer area that locates the irrigation controller as far as possible from the transformers. In speaking to Ron Lee the distance between the irrigation controller and the electrical pedestal at 2'-6" is ok as far as access is concerned, and speaking to Ray Schram at John Deere he thought this might work as well. Andres is working in this area so anything we can do to resolve this soonest is required. -- Stuart I. Roosth Architect 11226 Hillcrest Rd. Dallas, TX 75230 cell 214-868-9858 siroosth@gmail.com -- Stuart I. Roosth Architect 11226 Hillcrest Rd. Dallas, TX 75230 tel 214-378-6333 cell 214-868-9858 siroosth@gmail.com ________________________________ CONFIDENTIALITY. This electronic mail and any files transmitted with it may contain information proprietary to Deere & Company, or one of its subsidiaries or affiliates, and are intended solely for the use of the individual or entity to whom they are addressed, shall be maintained in confidence and not disclosed to third parties without the written consent of the sender. If you are not the intended recipient or the person responsible for delivering the electronic mail to the intended recipient, be advised that you have received this electronic mail in error and that any use, dissemination, forwarding, printing, or copying of this electronic mail is strictly prohibited. If you have received this electronic mail in error, please immediately notify the sender by return mail.