Just bought a Magna-Power Power Supply - Page 1
Forum section: electronics / testgear

author: czfyjf
author_rank: Newbie
timestamp: March 13, 2017, 10:30:51 pm
content: I just won an auction, and one of the items in the lot is a Magna-Power high power power supply. I don't have possession of it yet, so not too many details. I know that it is a TSD 800V, at least 20KW (it is 6U tall).I would appreciate suggestions on how to make it safe when I remove it. I suspect that it has been disconnected for several weeks or months, but is there anything that should be discharged before handling?I assume that I have no chance of testing its functionality (I am an EE and my home lab consists of a couple of multimeters). But, if you have any suggestions on testing it, I would appreciate that.Finally, anyone interested in purchasing a Magna-Power power supply?

author: jeroen79
author_rank: Frequent Contributor
timestamp: March 14, 2017, 10:01:25 am
content: Putting together a basic resistive load wouldn't be very hard.But it would take a lot of material to make one rated at 20 kW.And with 20kW at 110VAC (I presume) you should be worried more about tripping your circuitbreakers.

author: czfyjf
author_rank: Newbie
timestamp: March 14, 2017, 02:50:07 pm
content: Agreed on the circuit breaker. I looked at the data sheet, and I believe it runs on 220V mains.

author: Gregg
author_rank: Super Contributor
timestamp: March 14, 2017, 09:35:56 pm
content: The Magna Power website has a link to download a manual. It also appears that the unit you purchased requires 208V to 480V 3phase input power which may or may not be a problem.My concern is that someone that has to ask about safety to play with 800 VDC at 24A may be in a little over their head. High power DC, once it starts arcing, doesn’t stop because there are no zero crossings and if you manage to be part of the circuit, you can’t let go.Make sure you use fuses rated for DC and the voltage you are using; quality fuses are faster and more reliable than circuit breakers.

author: czfyjf
author_rank: Newbie
timestamp: March 15, 2017, 12:21:22 am
content: Gregg,That is my concern too!I know enough to know that I do not want to screw around with this thing.So, priority 1 is making sure that it is safe once it is removed from the seller's location. Priority 2 is to sell it. I bought the lot at auction because I needed some 17" racks for computer equipment. The power supply came along for the ride. I have no need for an 800V power supply, so I am going to try to sell it (or exchange it for some test equipment to outfit my non-existent lab). The auction listed it as "used-good" condition, but I would like to confirm that for my listing if I can do so safely. If not, I'll sell it without testing. No desire to get hurt--or worse.

author: mwright175
author_rank: Newbie
timestamp: April 18, 2017, 04:36:09 pm
content: Hi Czfyif,I would suggest measuring the the voltage between both DC buses. Additionally I would suggest doing the same for the AC input terminals. Depending on the age of the supply, the DC output terminals will have either an electronic bleeder or pure resistive bleeder so if the supply has been disconnected for any significant amount of time (few minutes) I wouldn't expect to see any voltage on the output. The AC input terminals you would expect to be fully discharged in less than a minute. The unit has some input capacitance that is used for its control circuitry but this will discharge through some of the internal safety detection circuitry. Worth noting, these supplies do have an input contactor circuit that disconnects the output of the supply from the input of the supply when off.My main suggestions would be to bring a multimeter and a few friends to help lift

author: pascal_sweden
author_rank: Super Contributor
timestamp: April 18, 2017, 07:50:04 pm
content: Best solution of all: just sell it "as is", and don't take all the risks of testing something which is way out of your league and imposes too many risks.