Built-in Power Supply Specs

[QuadeHale]

I've got a WispSwitch 250B that seems to be misbehaving pretty hard.
Not sure which firmware it is, 'cuz I can't log on to it. I'll be bringing the latest to me when I visit the site. But anyway...

The site it's on has awfully dirty power, but I've got a very good UPS on it.
The UPS is throwing "Site has a wiring fault" errors, oddly enough at the same time I lose connection to the switch and the APs/Backhauls attached to it.
The site seems to idle at 124VAC, but I'm going to do a further investigation and make sure there's no issues with the neutral or ground.

I'm wondering what the voltage tolerance is on these units - You show "110-120VAC", and coming from an electronics world I know precious few off-the-component-shelf power supplies have tolerances this narrow on input.

What's the real range? Commonly they're 90V-250V; I'm guessing since you don't have a toggle switch for 110/220 VAC on the back it's of this type.
And once I get this answer - can you update the datasheet so it's more accurate?

[lligetfa]

SIte wiring fault suggests potential between neutral and ground. That needs to be fixed to stop ground loops.

A standby UPS might not clean up dirty power at all and will simply flip over to the inverter when it get really bad. Consider an online UPS that runs from the inverter all the time if the power is really bad. Alternately, consider a Ferro-UPS or separate ferroresonant transformer such as a Sola.

[QuadeHale]

The site's ground is floating; L-N is 124VAC but the L-Ground is about ~84-94V. I'll be fixing that soon enough, but that wasn't my question!

My question was what the actual power supply specs are.

[sirhc]

The site's ground is floating; L-N is 124VAC but the L-Ground is about ~84-94V. I'll be fixing that soon enough, but that wasn't my question!

My question was what the actual power supply specs are.

The actual power supply specs are 110 to 120V. Power supplies are "certified" to specific a capacity and are safety tested at a nominal voltage range so manufacturers are going to say 110 to 120V or they open the door to liability.

The power supplies are rated to operate safely and efficiently at a specific range which is 110 to 120V, operating the power supplies outside this range will result in damaging the power supply and possibly causing safety issues.

I will say that operating at 84-94V WILL damage the power supply!

[LRL]

While we're on the topic of power supply specs. Any idea what the "hold up" time is on the 250w at full load? The reason I ask is we have had a couple of power failures and we use the tripp lite APS inverter/chargers and each time the power would go off we'd loose the switch. It would reboot and then all was fine. Radio's tripped too. Didn't appear to be an issue on the transfer back to utility, just on failure.

These Tripp Lite inverter/charges have a half cycle response time (16.6ms) where as a typical line interactive UPS is 2-4ms.

This switch has a lot of gear running on it and we're seeing 220-230W total usage. It may be time to go with the 24 port

[QuadeHale]

Who makes the PSU inside the unit? Do you have a datasheet?

I come from a background in electronics, and I can comfortably say that I have never seen an on-board power supply (hell, even an external supply) with a stated input voltage of 110-120VAC. I've seen 100-130, I've seen 90-136, most frequently I see something like 90-250 or 100-240.

Here in Ontario based on experience there's way more likelihood of overvoltage than under. Most sites sit at about 125-126VAC (250-ish leg-to-leg). If you are going to tell me that the power supply in the unit can actually handle 120VAC as an absolute maximum, I'm going to have to return it all, which is a damned shame.

But by example, a standard ATX power supply has a switch for 120 and 240... but when it's set to 120 it can handle between 90 and 145 volts (ish) in most cases (as long as it's not a 10 PSU)...

[sirhc]

They are "rated" at 110-240V AC, which is the range they safely operate and perform to specifications.

Consistently operating outside this range can damage the units and significantly reduce the MTBF and void your warranty.

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[QuadeHale]

"Input Voltage Range" means that that power supply can safely and properly function between 90 and 264VAC. Which is what I was after.
Edit: It also shows a "Rating" of 110-240VAC, which means 208VAC is perfectly acceptable.

I would be willing to bet if you were to look at AC input voltage logs on your UPSs, you will have plenty of sites over 120V (provided they are grid tied).

[sirhc]

Input range is what it "should" handle by design but is NOT tested, rated, or certified to do so.

The power supply will labor differently at different input voltages and will affect the MTBF and output rating.

Low input voltages is sometimes harder on a power supply then a little over.

[Omniflux]

Is this same information available for the upcoming DC powered product line?

I have several solar sites that range as high as 72VDC during battery equalization which is well above the posted 9-60VDC listed...