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WS-12-250-DC Max Power Consumption

Posted: Tue Jan 02, 2018 9:26 pm
by Beaman
I wanted to know what the Max power consumption of the WS-12-250-DC is? The spec sheet does not specify. I would like to power a SAF Integra WS using a single 48VH port, 7 Ubiquiti AirPrism radios using 24V ports, and a nanobeam AC using a 24V port. Total calculated wattage is 116W. Will this work?

I would like to power the switch using a Tycon Power system DC UPS. Model = TP-BC12-300. The Input voltage to the switch would be 12.5Vdc with a 12 amp max. Is this device usable or will I fry something? Spec sheet is attached below.

Re: WS-12-250-DC Max Power Consumption

Posted: Wed Jan 03, 2018 9:34 am
by Julian
Well, on the switch/radio side, you're fine. Max power dissipation on the 12-250-DC is 250w. UBNT uses an average for their max power consumption stats, I would expect draw on the prisms to peak higher than the datasheet stated max.

On the supply side, two things:

1: If you're using a separate power supply, why not buy a 48v supply and save some money by using a WS-12-DC? The 12-250's integrated power supply is a little redundant when fed by a power supply.

2: a 300w power supply is a little light - you may have no issues, the whole system might not power up - depends on how that manufacturer allows for inrush current (which on a 12-250-DC can be quite high for 20-40 microseconds on initial powerup)

Re: WS-12-250-DC Max Power Consumption

Posted: Wed Jan 03, 2018 11:58 am
by Beaman
Thank you for your prompt reply.

1: The Tycon system is a fail over system for when grid power fails. It would give me enough time to supplement a generator or pray grid power is restored within 8 hours. I would like to use 48v but unfortunately we are using 12v deep cycle batteries which would require me to use at least 4 of them if I wire them in series. My IP 65 box can only house two 12v batteries at present.

2: If what your saying is true about the Ubiquiti radios than the proposed system will not work according to the Tycon power spec sheet. Ubiquiti AirPrism radios use 9.5W according to their spec sheet. I rounded to 10W per radio and total system wattage came in around 116W with the Integra WS and the NanoBeam. There are two terminals one for load and one for battery. Load output is only allocated 120W according to the Tycon Power spec sheet. If inrush current is higher than normal than the system will turn off and on rebooting itself. The Tycon power system is only a true 210W rather than 300W. The battery side terminal is a unregulated wattage output meaning a full 210W can pass thru the battery terminal side. I am wondering if I can charge the batteries and power the DC switch using the same terminals on the Tycon Power unit?

Re: WS-12-250-DC Max Power Consumption

Posted: Wed Jan 03, 2018 1:05 pm
by Julian
No problem.

The recommended deployment is running the 12-250-DC across batteries (don't forget an appropriately sized fuse), and connecting a battery charger across your bank (again, with a fuse, ideally resettable). If you search around the forum, you'll run onto answers to more than a few of this type of question - Search box is at the top right.

We don't have a specific vendor or model number that we "recommend", as a policy - some users have recommendations, which you'll find using said search function.

The consideration you need to make is that load current will come off the top of charging current, which may or may not leave you with not enough power to recover charge (or power the load) after a mains outage.

Re: WS-12-250-DC Max Power Consumption

Posted: Wed Jan 03, 2018 8:17 pm
by lligetfa
Beaman wrote:The Input voltage to the switch would be 12.5Vdc with a 12 amp max.

Am I the only one who's calculator doesn't add those numbers up to 250W? Is it not volts X amps?

Re: WS-12-250-DC Max Power Consumption

Posted: Wed Jan 03, 2018 11:57 pm
by Dave
Les, I think he is talking about the actual Tycon device, which can only provide 120 watts out its load port.

Re: WS-12-250-DC Max Power Consumption

Posted: Thu Jan 04, 2018 12:34 am
by lligetfa
That's just it, so why is Julian saying "a 300w power supply is a little light"?

Re: WS-12-250-DC Max Power Consumption

Posted: Thu Jan 04, 2018 7:11 am
by Dave
I believe he is referring to the fact that a typical 300 watt power supply can often not be able to provide the inrush current that the switch needs to turn on.

Re: WS-12-250-DC Max Power Consumption

Posted: Thu Jan 04, 2018 9:56 am
by sirhc
So our SMART DC switches are designed to hook directly to the battery bank and then hook the charger to the battery bank.

If you want to power a switch from a power supply why not buy the model designed for this appliation.

If you would purchase the TP-BC48-300 then you could use the WS-12-DC which is designed to be powered by a power supply and costs less money than the WS-12-250-DC.

There are tons of posts on here discussing this:
https://forum.netonix.com/viewtopic.php ... wer#p22052
viewtopic.php?f=14&t=3371&p=22217&hilit=+smart+power#p22217
viewtopic.php?f=34&t=3356&p=22127&hilit=+smart+power#p22127
viewtopic.php?f=6&t=3350&p=22105&hilit=+smart+power#p22105




Re: WS-12-250-DC Max Power Consumption

Posted: Thu Jan 04, 2018 11:12 am
by Beaman
Here is what Tycon had to say said:

"Hi Bryan,

The Tycon TP-BC series Battery Chargers are total 210W continuous power output. We downgraded the rating because we were finding people that always push the limits at slightly over max temperature and slightly over max load and we were seeing some failures. So we downgraded the rating to make sure that we have plenty of margin to accommodate those that operate on the edge.

We recommend 120W continuous load max to give enough extra power available to charge the batteries quickly. Actual rated load output is 144W @ 12V, 192W @24V, 192W @48V. Note: We offer different models for the different voltages. We don't have a one size fits all.

The system also allows for 120% of rated load to accommodate startup current.
So if the rated load is 192W, then the startup power can't exceed 240W for a short duration.

Regarding the battery terminals: If you connect to the battery terminals you basically have unlimited short term power. You always need to size your load so that you allow some portion of the total power to be be available for battery charging. The total continuous power being limited to 210W on the TP-BC series. This 210W must be allocated by you between battery charging and load support.

Hope this helps.
Regards,
Scott Parsons
Tycon Systems
14641 S 800 W
Bluffdale, UT 84065
PH: 801-432-0003
FAX: 801-618-4220
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