There is no other wiring close to the sensors. There is likely some radio frequency interference on site because my client uses a radio transmitting system for his internet and phone connection. Can Hall Effect Sensors be effected by RF?
> Do you have any wiring close to the actual sensors or circuit board that > might be interfering with them? > > -----Original Message----- > From: vi...@solarenergydesign.com > Sent: Thursday, February 03, 2011 11:46 AM > To: RE-wrenches > Subject: [RE-wrenches] Data System Puzzle > > Sorry for the long post. I don't know how else to communicate this issue. > We installed an Energy Recommerce data system on a project last year that > we have not been able get working properly. Everything works except the > monitoring of the series string amperage outputs from the solar array. > There are 3 pv source circuit combiner boxes with 11 series strings of 14 > modules and 1 with 10 series strings of 14. Each combiner box feeds one > inverter with its own conduit run. The data system shows amperage from > each circuit consistent within each combiner box, typically with a range > of variance of about 1.5 amps DC between series strings. Each combiner > box will show totally divergent amperages. For example, combiner box 1 > might read 2 amps, combiner box 3 reads 10 amps, and at the same time our > clamp meters are reading the actual amperage at around 5 amps consistently > between every box for every circuit. The same combiner boxes will > consistently read either too low or too high. The problem may be in the > interface between the Hall Effect sensors that the circuit board in the > combiner box uses to measure the DC current. The Hall Effect sensors > deliver a calibrated voltage based on the strength of the magnetic field > around the series string circuit as it goes through the box. The combiner > box then calculates the amperage based on the millivolts that the Hall > Effect sensor produces. For example 500 millivolts equals 5 amps. The DC > output voltage of the Hall Effect sensor varies by about 50 millivolts or > more, so rapidly that itâs hard for our meters to follow it. We have > spent > countless hours on the phone with Energy Recommerce technicians trying > everything that anyone could think of to trouble shoot the problem. Their > system uses a MODBUS protocol for transferring the data and there seems to > be no problem with the data transmission or connectivity. I would love to > hear from anyone that sees a pattern to this problem that might help us > find a solution. > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > Northern Arizona Wind & Sun - Electricity from the sun since 1979 > -------------------------------------------------------------------- > Online Solar Store > Free Solar Discussion Forum > -------------------------------------------------------------------- > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
