Alternative Power sources - Solid State relay, 10A, 48V, with lotsa surge capacity?

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Solid State relay, 10A, 48V, with lotsa surge capacity?

William P.N. Smith

2006-01-21, 11:21 am

I've just measured the quiescent current drain on my 48->12V DC
converters, as seen at
http://golfcarcatalog.com/catalog/i...tId=971&id=2788
and it's right about 100mA. Not evil, considering the batteries are
220AH, (one percent per day), and the carts charge themselves every
two weeks in storage, but I'd like to cut it down to zero when the key
is off.

Anyone know where I can find a 10 amp (or better) solid state relay
that'll switch 48V and have a good surge capability? When I connect
the converters, I get a significant spark from charging the input
caps.

Thanks!

SolarFlare

2006-01-21, 2:21 pm

Not a solid state unit but I am sure they have an
equivalent in solid state. I just can't find it right
now.

We use a Potter Brumfield KUP series relays for our
SCADA outputs that can handle high voltage DC loads. It
has an arc snuffer magnet built in, therefore polarity
sensitive and larger contacts, giving current
making/breaking capability.

I found a few years ago, nobody makes a high voltage DC
(over 24v) contact relay with more than one contact
output in a relay package.

These units actually have two contacts internally wired
in series.

The model was something like KUP-3D11-120???

It is like this one except fewer terminals
http://www.relays.shopeio.com/inven...cat=Relays&sub=

"William P.N. Smith" <news2006a@compusmiths.com> wrote
in message
news:ttg4t1dqbaptdg52rint7c6j00s8kfoj1g@4ax.com...
> I've just measured the quiescent current drain on my
48->12V DC
> converters, as seen at
>
http://golfcarcatalog.com/catalog/i...tId=971&id=2788
> and it's right about 100mA. Not evil, considering
the batteries are
> 220AH, (one percent per day), and the carts charge
themselves every
> two weeks in storage, but I'd like to cut it down to
zero when the key
> is off.
>
> Anyone know where I can find a 10 amp (or better)
solid state relay
> that'll switch 48V and have a good surge capability?
When I connect
> the converters, I get a significant spark from
charging the input
> caps.
>
> Thanks!

2006-01-21, 2:21 pm

William P.N. Smith wrote:
> I've just measured the quiescent current drain on my 48->12V DC
> converters, as seen at
> http://golfcarcatalog.com/catalog/i...tId=971&id=2788
> and it's right about 100mA. Not evil, considering the batteries are
> 220AH, (one percent per day), and the carts charge themselves every
> two weeks in storage, but I'd like to cut it down to zero when the key
> is off.

Indeed. Got a similar arrangement on my domestic water system. My
system voltage is 24, but my pressure pump is a 12v (got a good deal on
it) so put it in with a 10 amp 24 to 12 converter. I use the
non-powered relay on the water pressure switch, though, to send the 24v
to the converter because exactly, I didn't like the idea of using my
electricity to keep the converter warm ;-).

> Anyone know where I can find a 10 amp (or better) solid state relay
> that'll switch 48V and have a good surge capability? When I connect
> the converters, I get a significant spark from charging the input
> caps.

Most of the electronic shops I use for that tend to have 32v max on the
coil side, but I gotta tell ya, I'm rather disenchanted with solid
state relays of late. Was doing a remote install last fall, using the
aux output of an Outback FX inverter to trigger a starter relay on a
genset (11.73v, ~3a from the inverter) and BOTH new-in-box solid state
relays I had brought didn't so much as twitch, and were of the 3-32v
operating DC voltage variety.
I've since switched back to mechanicals again. Solid state is cool
looking, but you can't expect hitting them with a hammer to "shake them
loose" like you can with a mech ;-).

For that stuff, I go "pro" and just call my industrial electrical
suppliers. Tell them the coil voltage, and the amps the contacts need
to take (and that they're DC!), and let THEM do the research for you;
and being industrial, the prices will probably be better than Home
Depot ;-).
I find that folks I buy #6 by the 300m spool from are willing to make a
few phone calls to keep me happy ;-).

DJ

SQLit

2006-01-21, 6:21 pm

"William P.N. Smith" <news2006a@compusmiths.com> wrote in message
news:ttg4t1dqbaptdg52rint7c6j00s8kfoj1g@4ax.com...
> I've just measured the quiescent current drain on my 48->12V DC
> converters, as seen at
>
http://golfcarcatalog.com/catalog/i...tId=971&id=2788
> and it's right about 100mA. Not evil, considering the batteries are
> 220AH, (one percent per day), and the carts charge themselves every
> two weeks in storage, but I'd like to cut it down to zero when the key
> is off.
>
> Anyone know where I can find a 10 amp (or better) solid state relay
> that'll switch 48V and have a good surge capability? When I connect
> the converters, I get a significant spark from charging the input
> caps.
>
> Thanks!

Any reason you can not use an knife switch? Like they use on battery
isolators?
Or pull out non fused disconnect?

I have used some of the hockey pucks and for the money and what your trying
to do I believe simple is better.

William P.N. Smith

2006-01-22, 12:21 am

"SQLit" <sqlit@qwest.net> wrote:
>"William P.N. Smith" <news2006a@compusmiths.com> wrote:

[color=darkred]
>Any reason you can not use an knife switch? Like they use on battery
>isolators?
>Or pull out non fused disconnect?
>
>I have used some of the hockey pucks and for the money and what your trying
>to do I believe simple is better.

I really need this to go on and off with the keyswitch, so it'll get
turned off when it's not in use. Then the key will control the radio,
the headlights, and all that stuff as well.

Adding coil current to my load doesn't thrill me a lot, but I might
have to go with a regular relay.

William P.N. Smith

2006-01-22, 12:21 am

"DJ" <dj_macintyre@hotmail.com> wrote:
>I've since switched back to mechanicals again. Solid state is cool
>looking, but you can't expect hitting them with a hammer to "shake them
>loose" like you can with a mech ;-).

Yeah, though you can't expect them to rust away in a marine
environment like mechanicals can. Turns out
http://www.omega.com/Temperature/pdf/SSRDC200_100.pdf comes in a
40-amp version, though it may get prohibitively expensive, so I may be
back to relays anyway...

Thanks!

Solar Flare

2006-01-22, 2:21 am

I gave you part numbers and where to look if you
weren'rt such a noce-in-the-air meathead you would have
got some hints from it.

Now you will have to admit you read it though...LOL

"William P.N. Smith" <news2006a@compusmiths.com> wrote
in message
news:54u5t1977oa3jrpsgoubcqa9bg575e5941@4ax.com...
> "SQLit" <sqlit@qwest.net> wrote:
wrote:[color=darkred]
>
solid state relay[color=darkred]
capability?[color=darkred]
>
they use on battery[color=darkred]
money and what your trying[color=darkred]
>
> I really need this to go on and off with the
keyswitch, so it'll get
> turned off when it's not in use. Then the key will
control the radio,
> the headlights, and all that stuff as well.
>
> Adding coil current to my load doesn't thrill me a
lot, but I might
> have to go with a regular relay.

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