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Transformer power consumption of GEM & Dashbox, POE?

Posted: Wed Dec 27, 2017 6:28 am
by techinin
Having trouble locating the technical information regarding the transformers used for powering the GEM and Dashbox. Can someone provide me the details on the (3?) transformers used in a GEM/Dashbox setup?

I understand there is one powering the GEM, one for the DashBox, and a third to measure line voltage.

Further details on the GEM transformer power consumption comparing Wifi vs Ethernet connectivity would be appreciated also, if available.

In addition, is it possible to power either of these devices via POE? If not, are there any future plans for POE?

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

Posted: Wed Dec 27, 2017 8:51 am
by Teken
techinin wrote:Having trouble locating the technical information regarding the transformers used for powering the GEM and Dashbox. Can someone provide me the details on the (3?) transformers used in a GEM/Dashbox setup?

I understand there is one powering the GEM, one for the DashBox, and a third to measure line voltage.

Further details on the GEM transformer power consumption comparing Wifi vs Ethernet connectivity would be appreciated also, if available.

In addition, is it possible to power either of these devices via POE? If not, are there any future plans for POE?
Details for all of the above is listed in the full installation manual on page 14. A quick snippet of the information provided in the manual follows below:

(3) Potential Transformer (PT) Input

The GEM may receive the PT signal from the 3.5mm phone jack (#3) or via the mini USB connector (#4). The 3.5mm jack is a stereo style jack providing two voltage range options, depending on the PT used. See “PT” section for more
information.

(4) Alternate Potential Transformer (PT) And 5VDC Supply Input

NOTE: This is not a standard USB port for communication.
This mini USB jack may be used as an alternative to the 3.5mm jack (#3), providing the PT signal is in the 333mVAC
(.333V) range. This USB jack us dual duty and may also provide an alternative to the +5 Volt DC power supply jack (#5).

(5) GEM Power Supply Input

This 2.1mm X 5.5mm barrel jack is for the 5VDC supply connection. The center pin is the (+) positive connection.

(6) Power Supply Access Terminals

This four terminal block provides access to the GEM’s +5V and +3.3V supply. This is reserved for future options and
special applications.

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

Posted: Wed Dec 27, 2017 4:38 pm
by techinin
I see the information on Page 14 of the installation manual. Though that doesn't give me power consumption numbers. On the Dashbox features page, I see energy usage of 2-4W. Any wattage estimates available for the GEMs (and ethernet vs wifi differences)? I also don't see any references to POE for either device, so I'm assuming they are not capable of being powered that way.

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

Posted: Wed Dec 27, 2017 5:01 pm
by Teken
techinin wrote:I see the information on Page 14 of the installation manual. Though that doesn't give me power consumption numbers. On the Dashbox features page, I see energy usage of 2-4W. Any wattage estimates available for the GEMs (and ethernet vs wifi differences)? I also don't see any references to POE for either device, so I'm assuming they are not capable of being powered that way.
The Dash Box consumes approx 2~4 watts depending upon hardware configuration and load. The GEM consumes approx 1~3 watts depending upon hardware configuration and load. Neither system can be powered via POE but the GEM can be powered via USB should that be required.

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

Posted: Wed Dec 27, 2017 8:56 pm
by dbreiser
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

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

Posted: Thu Dec 28, 2017 6:58 am
by techinin
Very interesting! Thanks Dave and Teken for your input. It does appear that a fully loaded GEM as in Dave's case is using significantly more than Teken's 1-3 W estimate. I am using this number for a battery bank sizing estimate. 12 W vs 7 W is significant. I may add another 1 W for an ethernet/wifi enabled GEM.

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

Posted: Sat Dec 30, 2017 2:41 pm
by Mustang65
Here is the GEM output for the 3 transformers.
Image

The transformers are located in water proof cases next to the Electrical service panel mounted on the back wall of my house. They are on the outside light circuit and at the time of this screen shot the Insteon On/Off module (for outside lights) was not plugged in.

I am in the process of setting up the GEM/DashBox to run off of (2) 6VDC, 12AH batteries in parallel with SOLAR charging. I am using 1Amp @ 5VDC, as the load for calculations using the 110VAC 5watts. Added a little buffer... 110VAC will be the backup should the battery voltage drop to low. Using a 5VDC voltage regulator to regulate the input voltage.

I do not use the Wi-Fi enabled GEM as I have Cat5 run out there from my HomeOffice.

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

Posted: Tue Jan 02, 2018 12:07 pm
by ben
The 11.8W seems a bit high, is it possible your CT leads are picking up some noise? At low-wattage, a little noise will cause a big difference.

You can try adding a jumper between the bottom 2 ports of the channel and see if the reading drops at all.

(See CH32 on Tekens photo below)

Image

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

Posted: Tue Jan 02, 2018 12:50 pm
by dbreiser
ben wrote:The 11.8W seems a bit high, is it possible your CT leads are picking up some noise? At low-wattage, a little noise will cause a big difference.

You can try adding a jumper between the bottom 2 ports of the channel and see if the reading drops at all.
Since it's a micro-40 CT, it's set up with the two legs of the CT in the center two ports. Are you suggesting I add a jumper between the bottom leg of the CT and the open bottom port?

That circuit does have a GFCI outlet, so noise is a possibility.

Dave

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

Posted: Tue Jan 02, 2018 1:20 pm
by ben
dbreiser wrote:
ben wrote:The 11.8W seems a bit high, is it possible your CT leads are picking up some noise? At low-wattage, a little noise will cause a big difference.

You can try adding a jumper between the bottom 2 ports of the channel and see if the reading drops at all.
Since it's a micro-40 CT, it's set up with the two legs of the CT in the center two ports. Are you suggesting I add a jumper between the bottom leg of the CT and the open bottom port?

That circuit does have a GFCI outlet, so noise is a possibility.

Dave
Yeah, correct, try adding the jumper there.