True Online UPS that won't break the bank?

[wahnula]

Hello,

Our small-office (10-user) network is located in a 70's-vintage double-wide trailer. It has been remodeled and looks OK, but the power...SHEESH!!! I had a dedicated new 30-amp line run to my office where all the switches, WAP, cable modem and SonicWall all plug into a mid-line TrippLite UPS. Plugged into the same dedicated line (not the UPS!) is a 110V room A/C that's only used sparsely....but when it is, and the A/C compressor kicks on, and all the connections drop briefly and I get the cheerful message: "A Network Connection is unplugged".

Connectivity returns within seconds, but I don't like it. I tried plugging the A/C into another outlet, that solved the network problem, but blew a breaker. The A/C is new and clean.

I am looking for a true Online UPS, where the equipment is always running on the battery and wall power is the backup power source. I've found them for $600-$4000 and wondered if anyone in this forum knew of any bargain units that are worthy. Remember, they are just backing up an 8-port gigabit switch, a cable modem, a SonicWall and a WAP, that's it.

If I can't find a decent choice, I'll just go back to plugging the A/C into the separate, original outlet. Thanks as always.

Tony

Users helping Users...

 

[beljunchoclit]

Wahnula just because a UPS is a true online doesn't mean it is running on the battery all the time - I don't know of a UPS that does. I assume you mean a unit that runs as you say on line and not in bypass with a switch to inverter when the need arises. You may have a problem with the UPS itself, (DC Caps, batteries or a transformer issue if its a small unit that bucks/boosts the output), as it sounds as if the current drawn on start up of the AC is causing the line voltage to drop so it's even possible you have a supply issue as well . The UPS 'SHOULD' be able to ride this out normally.
For small UPSs APCs are usually a very good choice.

 

[wahnula]

beljunchoclit

Thanks for the reply. I was reading in last month's PC magazine about the benefits of a "true online" UPS versus the standard design. I will re-read the article to see if I missed something. The UPS in use now is a low-end APC, it apparently doesn't handle the power issues quickly enough.

Tony

Users helping Users...

 

[beljunchoclit]

I thought true on line was the standard design. Unless the unit is small or transformerless I suppose. Perhaps the unit you have is too small.

 

[AndrewTait]

AC is well known for creating spikes in power supplies. Traditionally, A/C is on a separate supply to all other kit, epecially IT/Networking kit, as inevitably, UPS's don't switch over quickly enough. Most UPS's are also smoothing units, but the drop introduced by A/C is outside most UPS tollerences.

However, there has been a recent (in the last few years) change in thinking, along the lines that UPS powered kit should be run on batteries all the time, and just use the mains supply to charge the batteries up. However, I have not yet had the chance to implement one of these so I cannot comment on the pro's and con's of such thinking.

I would suggest having the A/C on a different circuit from the UPS.

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I got to the edge of sanity....then i fell off
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[beljunchoclit]

Andrew, I don't agree that the statement 'UPS powered kit should be run on batteries all the time' is true. A conventional UPS topology means that the UPS has the power running through it at all times. It doesn't actually 'kick in' as is usually wrongly claimed.
The supply comes into the rectifier, and then back out through the inverter. The battery is in circuit between the two power sections and float charges continuously.
I do agree however that the AC will cause spikes, (in theory the rectifier will completely remove these), and that it's usually fed from another source. All conventional UPSs are smoothing units as the input and output AC waveforms are isolated by the DC bus. As for tolerance this has no bearing on whether the UPS will do it's job.

The other type of UPS is one where the unit does run in bypass or filtered AC mains and switches to inverter when the situation calls for it. This type is the type that maybe affected more readily by power supply issues like that.

 

[wahnula]

Thanks for your replies. I have managed to isolate the UPS from the A/C via another circuit but there is still an issue with the UPS beeping whenever the A/C load is exceptionally heavy...I think this is due to the overall wiring in the building being poor.

We've had electricians come in and add dedicated circuits for the server, the server room A/C, and the engineering copier, but I think it's best described as garbage in-garbage out. We need a new power drop to the trailer and a complete overhaul of the electrical system to totally clean up the power problems.

Tony

Users helping Users...

 

[beljunchoclit]

The UPS beeping during heavy load puts forward one of two scenarios.

First, (if the heavy load is on the UPS), is your UPS is too small.
Second, (if the heavy load is on the site), then it sounds as if the high current draw is causing the supply voltage to drop and the UPS goes on to battery-which may or may not be entirely serviceable.
Third, something you are powering is causing disturbances on the supply line, be they harmonics or whatever.
If you have lots of laser printers in there, consider them a possible source of your problems, they draw VERY large currents at times.

 

[sean0102]

I agree True online ups is the way to go but can be expensive, so when i needed a ups for my pc's i looked around on the web and found value-ups.com which done various types and were competitive in price aswell so worth having a look

 

[beljunchoclit]

Yup. Depends how you choose to look at things though. An offline UPS is more efficient, (whether the money you save due to that is worth it or not I don't know), They have two main types, ones where the inverter runs off load until needed or one where the unit has enough capacity to keep the load going until the inverter starts up and takes over, (ferroresonant).
I gotta say as far as small UPS are concerned APC have cornered the market.

 

[EmrsnTech]

In theory the UPS should be ignorant of the line fault, as mentioned in a previous post the buck-boost circuitry should eliminate the issue. It SHOULD go to battery to ride out the sag, but if it is an 'offline' it may break load during the transfer if it is a large step load. most true online ups do run through rectifier-battery bank-inverter-static switch topology. so even in the case when mains is good, it will transfer to static switch (bypass) supply and alarm (over-temp, overload etc)

Any reputable company will have a solution for this, be it who i work for (Emerson), or APC or newer Powerware units.

Good luck, also as with the sag with the A/C comp kicking in. It will cause huge noise, as will large printers. Harmonics are bad !!

 

[beljunchoclit]

Well hello mate. I'm in the industry too, (Chloride).

 

[wahnula]

UPDATE

Hello all, old post but new situation...or more of the same.

We went through the Fall without incident, as my window AC unit was unused. Then...the central AC/heat went down. Please note my window AC was only to compensate for inadequacies in the Central AC system. I was ecstatic when I learned that Management was replacing the Central system, thus eliminating the need for all our window units.

The Central unit was replaced and has sat idle until the past few days, with warmer temps outside (Texas) the Central AC was turned on for the first time.

When the compressor kicks on, connectivity to the server is briefly lost. The AC is wired directly to the electrical service panel, to its own 240V breakers. This loss must be because the switch (on a separate circuit & UPS from the server) is cycling. There are also consistent errors in my Server Eventlog that the LAN NIC was down briefly.

I am using a basic SOHO APC shoebox-sized UPS on the switches/firewall/modem (which I would think are all low-draw devices easily powered) and a much larger CyberPower Smart UPS on the server which seems to be fine, no problems with the server. Should I just try a bigger/better UPS on my switch/modem/router? Or will that be throwing good money after bad? The office bookkeeper is using QuickBooks located on the server and is cursing every time this happens!

Getting a new service drop & panel to the office trailer is pretty much out of the question. I checked out the link above and it's dead. Any input on would be appreciated, thanks all.



Tony

Users helping Users...

 

[beljunchoclit]

Not sure what's happening here. If your AC is still causing problems then you may want to get a sparky to check it out. A fault somewhere could be causing your issues. The front end of your UPS, assuming it's true online should block mains bourne interference from what appears at it's output. If not then maybe you need to change what type of UPS you have. -
If you are not tripping breakers then there is likely a spike on your line when the AC starts or a brief voltage drop and if your UPS isn't true online then it's reaching the load before the UPS has the chance to do anything about it.
If it is a true online, make sure it's not configured to run in eco mode.