<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Carl,<div><br></div><div>Yes there are some options.</div><div><br></div><div>If you use a good pressure activated switch, you can turn on/off slow opening electric valves as flow changes. </div><div><br></div><div>IE so as the flow drops, the pressure drops and at the activation point, the relay closes one or more valves allowing the pressure to build up at which point the valve will open again.</div><div><br></div><div>For finer regulation you might need more than one valve to have a relay and more than one pressure switch.</div><div><br></div><div>Its can be pretty expensive, but it does work.</div><div><br></div><div>What voltage is the turbine? This helps to know if you can use the turbine power to control the valves.</div><div><br></div><div>thanks,</div><div><br></div><div>jay</div><div><br></div><div>peltz power</div><div><br></div><div> </div><div><div><div>On Sep 29, 2008, at 9:36 PM, Carl Emerson wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div lang="EN-GB" link="blue" vlink="purple"><div class="Section1"><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" face="Arial"><span style="font-size: 12pt; font-family: Arial; ">Hi there gang,</span></font></div><p class="MsoPlainText" style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" face="Arial"><span style="font-size: 12pt; font-family: Arial; "> </span></font></p><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" face="Arial"><span style="font-size: 12pt; font-family: Arial; ">We are looking at a 4kW PM hydro for a client and was wondering if anyone has done an automated control of flow into such a unit so as to limit the amount of water being taken from the stream in the Summer.</span></font></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" face="Arial"><span style="font-size: 12pt; font-family: Arial; ">This is usually done manually by closing down nozzles on the unit but here in NZ weather changes fast and the unit is 500M from the house. Summer rains can be significant and sudden.</span></font></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" face="Arial"><span style="font-size: 12pt; font-family: Arial; ">We are planning a 6inch pipe with around 100 ft of fall, the stream when low will allow a flow of 20Litres/sec but when high will deliver twice that amount.</span></font></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; ">Any suggestions??</span></font></div><p class="MsoPlainText" style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; "> </span></font></p><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; ">Thanks</span></font></div><p class="MsoPlainText" style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; "> </span></font></p><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; ">Carl Emerson</span></font></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; ">Freepower Ltd.</span></font></div><div style="margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Courier New'; "><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; ">Auckland NZ</span></font></div></div>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address:<span class="Apple-converted-space"> </span><a href="mailto:RE-wrenches@lists.re-wrenches.org" style="color: blue; text-decoration: underline; ">RE-wrenches@lists.re-wrenches.org</a><br><br>Options & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" style="color: blue; text-decoration: underline; ">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive:<span class="Apple-converted-space"> </span><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" style="color: blue; text-decoration: underline; ">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" style="color: blue; text-decoration: underline; ">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a href="http://www.members.re-wrenches.org" style="color: blue; text-decoration: underline; ">www.members.re-wrenches.org</a><br><br></div></span></blockquote></div><br></div></body></html>