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Input DC power
Posted: Thu Dec 13, 2018 8:08 am
by Ludvik
Hi.
WS-12-DC has in datasheet 54V as maximum (on web and switch case is 53V). Is it hard limit, or can work safely on "telco" sites with +56V to 60V? I was looking at this forum and I'm a little confused ...
WS-12-250-DC has in datasheet 9-72V, but on switch is wrote max 60V (photo on netonix.com). What is truth?
Thanks.
Re: Input DC power
Posted: Thu Dec 13, 2018 10:06 am
by sirhc
No, anything above 54V will damage the switch and could damage the devices you plug into it and power with 48V POE option and it simply passes out the input voltage as 48V POE option.
It will run with below 48V down to somewhere around 27V to 30V input but then again say you input 30V then 30V will be delivered as 48V POE option.
Please use 48V to 54V, 54V being MAX.
You mentioned Telco sites, MOST Telco sites use NEGATIVE 48V, if NEGATIVE DC power you must use the WS-26-400-IDC which is our only switch rated for NEGATIVE DC sites.
USE OF NEGATIVE DC POWER WITH WS-12-DC WILL RESULT IN WHITE SMOKE AND IS NOT COVERED UNDER WARRANTY. FLIPPING THE DC POWER CABLES TO INVERT POLARITY WILL NOT PROTECT YOU. NEGATIVE DC INPUT MUST BE REFERENCED AS 0V AND POSITIVE INPUT AS +48V TO 54V TO REFERENCE VOLTAGE OF 0V (NEGATIVE INPUT).
Re: Input DC power
Posted: Thu Dec 13, 2018 10:56 am
by Ludvik
Thanks. I use positive 48V.
And question about WS-12-250-DC? 60V or 72V?
In this post you say little something else thing:
viewtopic.php?f=6&t=1187#p8949
Re: Input DC power
Posted: Thu Dec 13, 2018 10:58 am
by sirhc
Ludvik wrote:Thanks. I use positive 48V.
And question about WS-12-250-DC? 60V or 72V?
In this post you say little something else thing:
viewtopic.php?f=6&t=1187#p8949
There are many post on this subject and an evolution of that product.
Originally the range was 9V to 60V but some people wanted higher due to charging voltages so the product was changed to allow up to 72V.
So OLDER original units 60V was the upper limit then hardware changes allowed 72V.
You should go off what it says on the decal on the front of the unit by the DC terminals.
Re: Input DC power
Posted: Thu Dec 13, 2018 11:04 am
by sirhc