deskjockeyed

Indeed, and news just in - it turns out to be the SMS communicator. The antenna groundplane was bonded to DC negative, the antenna ground was screwed into the case via the mounting nuts, hence a path from DC negative to earth via the panel casing conducting through the SMS communicator antenna. Well I'll be ******.

So I've been and done some further digging and there is indeed 300mA on the 12V+ battery output but a few milliamps on the negative, so it's got a parallel negative return somewhere or somehow if my electrical theory (Kirchoff's?) is right, however if I remove the battery negative the panel still dies?! I'm mildly less concerned now I know the battery is in use and it's not drawing from somewhere mad, but I would love to know where that current is sinking too or via. It seems strange to me that the current measuring pads and reading in Wintex reads current flowing via the negative too? I might change the "current measured" box to a "does the panel work on battery" tick box ??

125mA from the manual just the panel alone I believe! I think I'm going to have to strip the panel back down to nothing and go from there at this rate. Battery is charging fine and is healthy, removing battery on mains supply works as expected and doesn't affect the panel, and removing battery on battery power results in the panel dying, so everything as expected. I do suspect maybe some internal failure though. Yep. If the mains and battery supplies are removed the panel dies, which suggests to me there's no parallel supply? But there could be some weird link with the battery negative enabling circuit completion or something. My thoughts were something like a SAB providing a 12V supply by being powered in parallel from the PSU200XP or something. I might completely disconnect the panel back to nothing and start afresh just in case there is a strange potential difference being generated somewhere. If it was drawing from the PSU200XP however I'd expect a fuse pop in the PSU200XP or a very elevated current draw from the PSU200XP (above an amp), but I'm not getting this. Thanks for your replies all, started the brain working on some more potential causes!

Evening all, I've got a proper headscratcher of an issue with a few years old Premier Elite 48 that I'm wondering if anyone else has seen? For reference, the set up is a PE48 control panel, 8XP-W, PSU200XP and Smartcom. Everything as far as I know and can see is set up correctly, including the removal of the 12V+ from the panel to the PSU200XP network terminals. The PE48 panel has 8 x QDs, the 8XP-W, an Odyssey X and an Odyssey 5E and the Smartcom connected to it, as well as an SMS module on the Digicom outputs and supplies all of these with 12V. Recently during a battery test (17Ah 12V Yuasa, 2 years old), the current draw of the panel was measured when on mains supply and on battery. On mains: approx. 300mA @ 13.7V. On battery: approx. 10mA (yes, 10mA) @ 13.1V to 12.6V. This current reading was verified in Wintex, via the current measuring pads on the panel, and via an ammeter in series with the battery - they all measured the same. How in god's name could it be 10mA?! The panel works fine in battery mode, I can use the keypads, sound the SABs and strobes, connect via Wintex, see the PIRs detecting operating, no fuses blown - the panel draw simply cannot be 10mA. So far we've tried swapping batteries just in case the battery was knackered, disconnecting SABs, communicators, network devices and aux devices just in case there was a parallel path and double checked the 230V wiring to ensure there's no weirdness there. We also disconnected the battery when the panel was isolated from mains and it died immediately suggesting no parasitic or parallel supply from anywhere? Any ideas...? I'm stumped!