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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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48 volt uninterruptible power supply
HI All
I wonder if anybody out ther has experience with this piece of kit - or similar. This unit has a 2-part black metal case enclosing a battery charger / invertor PCB, with space for Dryfit battery. Fitted with rubber feet and keyhole slots for wall-mounting. Specifications * Input 88 to 275 VAC, 43 - 63 Hz, 0.6 Amps, single phase * Output -48v DC, 35 Watts continuous, stored energy time 6 hours, ambient temperature -10 to +55 centigrade * Manufactured by L3 Communications - Model no UPS10B00 The problem I'm experiencing is that, when connected to the mains, the unit happily charges the dryfit battery, but does not 'invert' (i.e. produce the 48v) when the mains is disconnected. I'm guessing that the control circuitry is sensing the mains dropping out (as the 'mains' led goes out) - but the unit doesn't seem to want to go into 'invert' mode. There's a multi-way connector strip on the outside of the case - which has connections for 48v, plus a number of status connections - but I have no documentation on these. Would you expect to have to 'do something' (as in wire links on the multi-way strip) in order to kick the thing into operation ? Possible thoughts so far a) Faulty unit - not likely as units were sold as NOS, and the two units I have behave in excatly the same way b) Faulty dryfit battery - don't think so - they hold a charge ok - and terminal voltage remains around the 12v mark after the mains drops out c) User error ( ! ) - in that I need to 'do' something more in order to 'make it happen' I will be contcting the manufacturer to see if they can shed any light on the matter - but I wondered if some kind soul out there might have 'been there, done that' already...? Thanks in advance Adrian Suffolk UK ======return email munged================= take out the papers and the trash to reply |
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Hi Matt
Just to follow up on my earlier post - and in case anybody else is searching in thre future for the answer to the same question :- It seems that this UPS wants to see a link between pins 1 and 6 on the terminal strip. I think this is a kind of 'UPS enable' link - which prevents the UPS from functioning during shipping. It also wants to see some kind of a load on the 48v terminals (I used a 470R / 2W resistor. If both of thesethings are present, AND mains is applied, then 48v appears at the output terminals. Subsequently, if the mains then drops, the unit goes into UPS (battery backup) mode. In short, it works ! - but only if the above conditions are satisfied, and in the right sequence........ cunning, eh ? Thanks all Adrian ======return email munged================= take out the papers and the trash to reply |
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HI Matt
On Wed, 06 Apr 2005 05:11:23 GMT, wrote: Adrian Brentnall adrian-the papers and the wrote: It seems that this UPS wants to see a link between pins 1 and 6 on the terminal strip. I think this is a kind of 'UPS enable' link - which prevents the UPS from functioning during shipping. Glad to hear you worked it out! (Did you find documentation, or just start playing with it?) Both ! There's a similar unit on the web at www.powerstream.com/Product2.htm - and it sort of mentions that there's a need for a link between 1 and 6... But the sequence of operations turns out to be critical..... which caused me some confusion (doesn't take a lot, these days !) I bet if you start playing with a voltmeter or ohmmeter you will find that some of the other terminals open and close with the mains, and possibly open and close with a good/discharged battery. Correct - as per the weblink above It also wants to see some kind of a load on the 48v terminals (I used a 470R / 2W resistor. Did the red and black terminals (1 and 8) turn out to be the 48 V terminals? 7 & 8 - yes. Plenty of 'juice' there - certainly enough to cook the first resistor I used as a load g Many thanks for your input - it does help to be able to 'bounce' ideas off another person - my 2 dogs are clueless when it comes to electronics ! Thanks Adrian ======return email munged================= take out the papers and the trash to reply |
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