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Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Tue Jan 02, 2018 1:26 pm
by Teken
Just some added data points in case others want to do the same. The GEM is extremely flexible along with being highly accurate. There are several things you can do to fine tune the readings so what you see and measure is as close to being 100% accurate.

- Use higher tolernace CT's like the Micro 50
- Calibrate the GEM's PT value referenced to a True RMS digital multi-meter (DMM)
- Adjust and calibrate the PT Type & Range for those specific channel CT's using a *validated* resistive load. Such as a incandescent light bulb, hair dryer, space heater.
- Fine tune the current constant ~ Do not adjust unless you know what you're doing.

Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Tue Jan 02, 2018 2:02 pm
by dbreiser
The jumper did reduce small noise in the watts signal, but now the circuit is reading about 0.3 W higher.

Another possible parasitic draw is that the power strip I'm using is/was a surge suppressor. It used to have a power-on indicator light (which no longer functions). But if there's anything inside that box that would create a small power draw, that could be elevating my reading.

Dave

Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Tue Jan 02, 2018 2:56 pm
by Teken
dbreiser wrote:The jumper did reduce small noise in the watts signal, but now the circuit is reading about 0.3 W higher.

Another possible parasitic draw is that the power strip I'm using is/was a surge suppressor. It used to have a power-on indicator light (which no longer functions). But if there's anything inside that box that would create a small power draw, that could be elevating my reading.

Dave
Hello Dave,

As a reference data point I have many surge strips and bars from APC, TripLite, Panamax. All of them show a constant vampire draw from 1~4 watts. :? :|

Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Tue Jan 02, 2018 3:22 pm
by dbreiser
Teken wrote: Hello Dave,

As a reference data point I have many surge strips and bars from APC, TripLite, Panamax. All of them show a constant vampire draw from 1~4 watts. :? :|
Sigh. Another project. I unearthed an old TrippLite IB-8. It shows no increase in the circuit power when I plug it into the strip feeding the GEM etc. That TrippLite also used to have an illuminated switch for which the illumination no longer functions. Kind of a pain in this case, because there is no On-Off label on the switch (and now no light). Anyway, I can swap the TL in place of the strip now in use and then test the old strip for vampirism.

Thanks for the info.

Dave

Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Tue Jan 02, 2018 6:12 pm
by dbreiser
dbreiser wrote:I have a circuit that only powers my GEM, dashbox, cable modem and gigabit switch. Without the modem and switch plugged in, the GEM reports that the power use for the GEM, reference PT, and dashbox is 11.8 W. My GEM is serial-only (no WiFi or other wireless), and the dashbox is hardwire ethernet only. I didn't unplug the comm cables from either the GEM or dashbox during the test.

I do have all 32 power channels populated with CTs. I also have 6 temperature probes on the 1-wire circuit, both 'powered' pulse counters occupied, and 1 of the dry contact pulse counters connected.

Dave
Oops. Make that 3.5W for the GEM, Dashbox, and reference PT.
No need to invoke vampire power suckers when my problem is I can't see or count. The extra 8W was my video splitter amp. :( It's only the biggest wall wart I have in that cluster.

Dave

Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Tue Jan 02, 2018 6:14 pm
by Teken
That's more to what I've seen here with my two systems. Along with monitoring other members systems.


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Re: Transformer power consumption of GEM & Dashbox, POE?

Posted: Wed Jan 03, 2018 8:47 am
by techinin
It looks like 4W is a safe number to use based on all the replies. Thanks to all for taking the time to look into this.