Re Astrofest power outages

Gerald Sargent · #1 20-08-2010, 08:54 PM

This is something we are going to have to "live with" Pat Pearl
did a superb job of testing things but general leakage adds up.
Umart, in Milton Rd Brisbane (and their other stores) are oiffering
an APC UPS device for $157 that is superbly engineered and
delivers a massive 650 watts. It is their Back UPS CS 650va, USB,
650 va/230 volt. It is but 165x234x91mms, and weights 6kgs. It has
a lot of sockets. If this is interpreted as advertising well I am
guilty, but suffering 8 outages in one evening has "pulled me into
line" so I shall be prepared in future. Gerald.

Jeffkop (Jeff) · #2 20-08-2010, 10:43 PM

Sounds like bloody cheap insurance to me Gerald ... as a matter of fact .. for that price anyone doing long exposure imaging where ever it is should have this sort of insurance. WHAT in astro imaging is 157 bux AUS ?????

Its the next thing Im buying at that price !!!!!!!

Octane (Humayun) · #3 20-08-2010, 11:10 PM

Gerald,

Thank for the heads up. Will see if there's something similar down here in the ACT.

Cheers.

H

jjjnettie (Jeanette) · #4 20-08-2010, 11:26 PM

Thanks for that Gerald.

[1ponders] (Paul) · #5 21-08-2010, 10:05 AM

Good one Gerald. You won't regret it. Its amazing the peace of mind a UPS brings when others are in the process of reinitializing mounts, redoing alignments, re-centering objects, recalibrating guide programs, checking to make sure its all happening as it should be, before finally sitting back and mumbling to themselves.

renormalised (Carl) · #6 21-08-2010, 10:23 AM

Problem is, UPS's have only a limited time supply (depending on how big they are) because their internal batteries are only made to supply enough power to a computer and accessories to be able to shut everything down safely. You may get some more time out of one powering a mount etc, but not much more, so you're not really saving your subs. You'd have to shutdown within the normal discharge time frame or risk doing damage to the UPS and your equipment. Your best bet is to grab yourself a small portable generator with an inverter built in. You can still get an UPS and I would, because they condition the power supplied to your equipment.

Kal (Andrew) · #7 21-08-2010, 10:49 AM

Carl, you are right, that UPS will only supply a 400W load for 4.7 minutes, but I would imagine that most people would be using laptops which would have their own batteries to keep them running, so the UPS would provide insurance to mounts & CCD cameras. At 150W load, it will last about 20 mins, with a 100W load 35 minutes.

DavidTrap (David) · #8 21-08-2010, 12:19 PM

I second what Gerald and Kal saying.

I measured my current draw when I got home with a meter I bought at Jaycar. It peaked at ~150W. A UPS designed to run at 650W for a couple of minutes would power my setup for much longer - enough time for someone to reset the RCD.

DT

Gerald Sargent · #9 21-08-2010, 12:55 PM

Please note that the UPS I suggest is not a small one. This one will hold up a Desktop PC with 15" LCD Monitor for 50 minutes. Gerald.

[1ponders] (Paul) · #10 21-08-2010, 12:57 PM

There in lies the rub.

Laptops kill them quickly for the size I have, but operating just the mount without slewing, USB hub to keep the data flowing for autoguiding and camera download, in my case the SX-h9 (and yes the TEC was still running) worked an absolute treat. Once the exposure is done the mount and autoguiding can hum along quite nicely for an extended period without any problems. It was probably close to 10 min for the longest outage and I was able to keep going including keeping the camera going with np at all.

I will be taking a deep cycle battery, trickle charger and inverter next year. Just to be on the safe side.

Tandum (Robin) · #11 21-08-2010, 12:57 PM

650va is closer to 400watts not 650. I was looking at this one from computer alliance for $80. It's 700va or 420watts and is basically a power board.

[1ponders] (Paul) · #12 21-08-2010, 01:04 PM

that is exactly the same as I have Robin, except mine is on rated at 500VA and has normal gpo points. Three plugs for backup power and another three for just surge protection. Works a treat! As a bonus if you want you can hook it up to the laptop and manage the power drain by monitoring the UPS status.

Oh and btw at no time at Astrofest did I get a warning that the backup battery was getting low.

Great price. Mine cost me around $120 18 months ago

Tandum (Robin) · #13 21-08-2010, 01:10 PM

I think they have the 500va for $70. I find the battery normally starts to go after 2 or 3 years when it's on a computer and always charging. I'm sort of wondering how long they'd last when not plugged in for extended periods.

[1ponders] (Paul) · #14 21-08-2010, 01:22 PM

Yep that's it Robin. Mine hasn't been plugged in since Astrofest last year, until earlier this year when I hooked it into the observatory, say April, May this year, so 10ish months without connection. It now gets connected each time I use the observatory (half a dozen times a month), otherwise its offline.

We have a UPS at the Mapleton Observatory but we never us it. Each time the power goes out you have to reset it. The alarm doesn't stop if the power comes back on. This one does. As soon as the power comes back on it resets. This is a huge bonus with a UPS if it is under the floor of the observatory and you have to crawl through the floor space to reset it.

Or if you have an automated system and the alarm goes off in the middle of the night while you are catching up on short shut eye.

While I've only used these two (I can't remember the name of the other one. Quickly forgotten) I much prefer my Eaton one.

Oh and disclaimer:

I don't have anything to do with Eaton or the place i bought it from (Lawrence and Hanson). Just a very happy camper

Edit: Oh and one other thumbsup for it. While setting up the layout of the observatory I had the mount running, camera imaging and hub online, laptop on battery, for a couple of hours. There were a number of times I shifted the powerlead trying different entry points into the observatory and trialled each setup that way for an hour or so. The Eaton handled being plugged in live and unplugged without a hiccup and kept the SX, hub and mount running as if nothing was happening. I'm not an electrician or technician in anyway (

) so I couldn't say what sort of havoc that may have been causing but my astronomy gear never missed a beat all night. It impressed me.

Tandum (Robin) · #15 21-08-2010, 01:33 PM

Sounds like the maplton one has a problem, they should clear after power is restored. There are basically 2 types of UPS. A straight battery backup type, like those power board things and a line interactive type. Line interactive types normally have AVR circuitry which monitors incoming AC supply and regulate it to give a smooth 240v out as well as battery backup. I don't think I really need that sort of UPS on this gear and the straight battery backup ones are normaly cheaper.

[1ponders] (Paul) · #16 21-08-2010, 01:45 PM

I would have thought the same, but its done it right from out of the box. The power comes back on in the USP np but the alarm doesn't stop. Very annoying

Gerald Sargent · #17 21-08-2010, 01:52 PM

To add to Robins comments, one should not that most of these have
a square wave output, ideal fot those small ac/dc switched mode converters
but bad news for things using conventiuonal (heavy) transformers.
For the latter one has to buy a much mor expensive version of UPS that has
a pure sine wave output.
Personally I think the type I recommended may be a bit over the top for
some but as a ubiquitos recommendation I think it is a good buy. Gerald.

Kal (Andrew) · #18 21-08-2010, 07:24 PM

Quote:

Originally Posted by Tandum

I think they have the 500va for $70. I find the battery normally starts to go after 2 or 3 years when it's on a computer and always charging. I'm sort of wondering how long they'd last when not plugged in for extended periods.

Every UPS battery I've seen is SLA, so if it isn't topped up every 3 months or so it will kill the batteries.

mozzie (Peter) · #19 21-08-2010, 07:35 PM

dont worry about imaging next year and come over to the visual field !!!!we dont have these problems

oh dear i can here the repercussions coming !!!!!!!

DavidTrap (David) · #20 21-08-2010, 07:52 PM

Many of the UPSs have two sets of sockets - some are backed up by the battery and some are just surge protected (as Paul mentions above)

You could plug your laptop into the surge protected sockets only, and then it will change over to its internal battery - leaving the UPS battery to continue to power mounts, cameras, hubs, etc for longer.

DT