Re: [AFMUG] 48DC Surge Protector

Fri, 31 Jul 2015 10:13:59 -0700

The single most power hungry thing I have is a Telrad Compact 1000 which is about 2.5 amps. 

I guess a CMM4 with 8 450 AP's could use more like 6 amps.

I can't think of any larger loads you would have in the WISP market.
LEDs showing a failure of the surge devices are hard to do. They can fail high or low impedance. The cost of the test circuitry would exceed the cost of the rest of the device. I could put on a voltage and load current set of LEDs like the 444 surge suppressors, but how much load would we want to be able to pass? 
I presume perhaps 10 amps max would be OK?
I can’t understand why anyone would want to create a polarized suppressor. It only saves a few pennies and would force you to build, stock, sell, ship two different versions. I can do screw terminals or the phoenix plug types like I use on the GigE-POE-APC units. If you want to use a fork terminal I think you would have to cut one off. But it is nice to be able to terminate the wires and then plug them all in. Also makes it quick and easy for troubleshooting. Quick to plug in and unplug. 
*From:* Adam Moffett <mailto:[email protected]>
*Sent:* Friday, July 31, 2015 10:16 AM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] 48DC Surge Protector
I don't think I've seen one that was anything other than a screw terminal. Usually it's the type with a square washer thing under the screw head that clamps down when you tighten the screw. Perfect for fork terminals, or solid wire.
I was curious about something. Connectronics sells a separate "+/-48V" and "-48V" model (82-3750 and 82-8694 respectively). We've only ever used the +/- model, which does not ground either power terminal. It does have a + and - marked on the terminals and a green LED that turns on when there's power present (good feature btw).
I don't understand why there's a -48 version at all. If your equipment has a positive ground, and your supply has a positive ground, why would you want another positive ground in the middle?
Separately: Thinking about the green LED made me wonder how hard it would be to have a red LED come on when the power supply side is connected, but there's an open circuit on the load side, such as the load being broken/disconnected or the gas tube being popped.
So, just two screw terminals that are surge protected to the ground bus. That is doable. Put a gas discharge tube on it along with some faster semiconductor devices. Some fancy DC power surge protectors have some choke coils and an in and an out. 
*From:* Jason McKemie <mailto:[email protected]>
*Sent:* Thursday, July 30, 2015 10:09 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] 48DC Surge Protector
Just a standard screw terminal would work fine.

On Thursday, July 30, 2015, Chuck McCown <[email protected]> wrote:

    What connectors do you want on it?
    *From:* Jason McKemie
    <javascript:_e(%7B%7D,'cvml','[email protected]');>
    *Sent:* Thursday, July 30, 2015 1:50 PM
    *To:* javascript:_e(%7B%7D,'cvml','[email protected]');
    *Subject:* Re: [AFMUG] 48DC Surge Protector
    I didn't think he was making anything yet.  One that fit in the
    APC rack mount unit would be perfect.
    On Thu, Jul 30, 2015 at 2:23 PM, Lewis Bergman
    <javascript:_e(%7B%7D,'cvml','[email protected]');> wrote:

        Chuck has one.
        On Thu, Jul 30, 2015 at 11:45 AM, Jason McKemie
        <javascript:_e(%7B%7D,'cvml','[email protected]');>
        wrote:

            Where did you buy these?
            On Thu, Jul 30, 2015 at 10:29 AM, Paul McCall
            <javascript:_e(%7B%7D,'cvml','[email protected]');> wrote:

                When we investigated this to protect our 48v
                syncInjectors…. DJ with Shelby Broadband turned me
                onto these…   we have only had them in place for a
                few weeks so cant really comment much.

                
http://www.citel.fr/en/produit/citel-AC-power-SPDs/citel-Type-2-DC-surge-protector/surge-protector-DS230DC-series/ds230-48dc.html

                *From:*Af
                [mailto:javascript:_e(%7B%7D,'cvml','[email protected]');]
                *On Behalf Of *Sean Heskett
                *Sent:* Thursday, July 30, 2015 11:15 AM
                *To:* javascript:_e(%7B%7D,'cvml','[email protected]');
                *Subject:* Re: [AFMUG] 48DC Surge Protector

                For Ethernet or for just DC power?

                For Ethernet we use the gigE-APC-POE from wbmfg.com
                <http://wbmfg.com>

                For DC power we use 1,3 or 10 amp "car fuses" in a
                fuse block.



                On Thursday, July 30, 2015, Adam Moffett
                <javascript:_e(%7B%7D,'cvml','[email protected]');>
                wrote:

                Does anybody have a SS for DC power lines that they
                like? Transtector is a little pricey at $200/each so
                I was looking for alternatives.
-- Lewis Bergman 
        325-439-0533 <tel:325-439-0533> Cell

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