The biggest difference between the two meters is the TM500 uses a RJ11 plug and telephone style cable between a shunt board and the meter. Since amphour meters work by measuring voltage drop across the shunt my guess would be that the meter has lost connectivity to the shunt, probably through those pinche connectors. Higher resistance = lower voltage measured = decreased current flow recorded. Any oxidation or corrosion of the tiny little pins will create inaccurate readings.
Try wiggling the connectors and repeatedly plugging and unplugging them at both ends, and see if that clears up the issue. If that works, put a dab of silicone grease on the connectors to minimize chances of it happening again. Phil Undercuffler On Mon, Dec 13, 2010 at 10:53 PM, Howie Michaelson <[email protected]>wrote: > Hi All, > > In the past 2 months, I've had 2 separate clients with 48 volt SW systems > have their TM500 stop resetting amphours - even after there is no current > flowing into the bank for hours. The meter never goes below "0" amp hours > and always shows "Full" SOC. These are TM500s that have behaved properly > (at least in that way) for years. Anyone else ever seen this? Another > time bomb? Any fix other than replacing with a Trimetric 2020. I've seen > bizarre behavior from the TM500 before, in a 48 volt system setting up > some high frequencies which effectively shut down the C40 on the system, > but haven't seen this anomaly before these 2 systems... > > Thanks, > Howie > -- > Howie Michaelson > NABCEP Certified Solar PV Installer™ > > Sun Catcher, LLC > Renewable Energy Systems Sales and Service > VT Solar & Wind Incentive Program Partner > http://www.SunCatcherVT.com > (cell) 802-272-0004 > (home) 802-439-6096 > > > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > 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 > >
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