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DC - DC Convertor Question

DC - DC Convertor Question

DC - DC Convertor Question

(OP)
Hello all!

Have a quick one here:

We have a converter ASTEC LPS155 that can be feed 100-120V ac or up to 250 dc. Output is 48 V dc.

On the input connector, there are three (3) pins:

1- Ground
2- Live
3- Neutral

There are no (+) or (-) signs. Since we're feeding it
with 250 V dc, where (+) and (-) leads  connect?

I blow one converter with (+) lead on neutral and (-) lead
on live, and I don't want to blow a second one. Any help?

Thanx
ponder

RE: DC - DC Convertor Question

Do you have a voltmeter?

RE: DC - DC Convertor Question

Hello unclebob;
Here is the info sheet from Astec.

http://www.astec.com/products/datasheets/lp/lps150revb.pdf

I phoned technical support. I got through almost immediately.
I got an excellent responce fom the technical person.
(case #31863)
The connections are: Positive to Line. Negative to Neutral.
There is an internal fuse that may have saved your convertor.
The replacement is a 5 Amp, 20 mm, Quick-Acting fuse.
yours

RE: DC - DC Convertor Question

(OP)
Thanks waross, you're very helpful, as usual! thumbsup2

 

RE: DC - DC Convertor Question

waross; Why didn't you ask them why it matters?  I can't imagine any reason why feeding a rectifier bank would matter...  Can you?

I would rather think that the inrush of charging the front end by a "snapped on" 250Vdc blasted the fuse.

uncle; you may need to install a resistor or some other device to limit the inrush if your fuse mysteriously blows occasionally.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: DC - DC Convertor Question

I am wondering why, in the absence of firm information, would your first try be  (+) to neutral and (-) to "live".

Just curious.

RE: DC - DC Convertor Question

Me too. It shouldn't matter, really. The AC mains is changing polarity 100 or 120 times per second. So you should be able to connect either way.

Gunnar Englund
www.gke.org

RE: DC - DC Convertor Question

Hello itsmoked, GTstartup, and skogsgurra.

Quote:

Hello waross; Why didn't you ask them why it matters?
I can't think of a reason either. I wish that I'd asked.
sorry
respectfully.

RE: DC - DC Convertor Question

Hey waross nothing to be sorry for.. You did more than any of us!poke

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: DC - DC Convertor Question

Active is the (+) connection and the neutral wire (-) usually ends up being connected to the ground stake at some point.

RE: DC - DC Convertor Question

"feed 100-120V ac or up to 250 dc."  This is not correct.  I was able to ind a picture of the ASTEC LPS155 and the label says 100-127AC, 200-250AC, DC 220-300, and that jumpers must be changed.  This unit has a voltage doubler for low voltage.  There certainly could be some problems if the jumper was not switched from voltage on the caps.

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