Re: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

[Nate Duehr]

Eric Lemmon wrote:

> I am amused by APC's assertion that its device is the only unit of its kind
> in a 1U rack mount.  Perhaps APC hasn't heard about Pulizzi Engineering's
> line of asynchronous transfer switches, such as this one:
> 

APC's heads are pretty big for as cheap as their stuff is, when you look 
inside them, and their construction techniques.  I've used a lot of APC 
stuff in data centers, but in the Telco Central Offices...

> The Pulizzi transfer switches have been the "gold standard" in the aerospace
> industry for years, and hundreds of them are in service at Cape Canaveral,
> Kennedy Space Center, and Vandenberg AFB where super-critical equipment
> supports both manned and unmanned space launches.  We often use the term
> "Pulizzi" as generic, because they are reliable and widely used.

The Pulizzi (for some reason people in telco pronounce this 
"Poo-loo-zee") and the stuff from Server Technologies in Utah are all I 
see switching critical -48 VDC loads.  (www.servertech.com)



Both the ServerTech and Pulizzi products are NEBS compliant, most APC 
stuff isn't.  Try finding PCs that are sometime.  That's a joy.  (HP 
makes them.)

> If there is any possibility that the two incoming power sources may not be
> exactly in phase with each other- as when one source may be an engine-driven
> generator- a transfer switch that can handle asynchronous sources must be
> used.  The Pulizzi switch in the link above is such a device, and it is not
> cheap!

Definitely not cheap!  Neither are the ServerTech devices...

Nate WY0X

RE: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

[Eric Lemmon]

My definition of "seamless" is no interruption at all, which usually means
an on-line UPS in which an inverter runs continuously on a DC supply that
floats on batteries.  The APC unit on the link shown in the original posting
must disconnect from one source before connecting to the other source- and
that is not seamless.  That said, most equipment that is built to CBEMA
standards will tolerate a power loss of several cycles without crashing, and
each cycle is about 17 milliseconds.  Perhaps APC defines the word
"seamless" as "nearly continuous."

I am amused by APC's assertion that its device is the only unit of its kind
in a 1U rack mount.  Perhaps APC hasn't heard about Pulizzi Engineering's
line of asynchronous transfer switches, such as this one:

The Pulizzi transfer switches have been the "gold standard" in the aerospace
industry for years, and hundreds of them are in service at Cape Canaveral,
Kennedy Space Center, and Vandenberg AFB where super-critical equipment
supports both manned and unmanned space launches.  We often use the term
"Pulizzi" as generic, because they are reliable and widely used.

If there is any possibility that the two incoming power sources may not be
exactly in phase with each other- as when one source may be an engine-driven
generator- a transfer switch that can handle asynchronous sources must be
used.  The Pulizzi switch in the link above is such a device, and it is not
cheap!

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of skipp025
Sent: Sunday, August 03, 2008 9:24 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

The caveat is in the web page text... 

[pasted APC web page text] 
> If the primary power source becomes unavailable, the rack ATS 
> will seamlessly source power from the secondary source without 
> interrupting critical loads. 
[end pasted text] 

Depends on what your interpretation of "seamless" is... 

There will be some fractional switching time interruption of 
the mains power else they have some new/secret method for placing 
a lot of electronics and energy storage in a 1 RU (rack unit) 
box. 

cheers, 
skipp 

> Chuck Kimball <[EMAIL PROTECTED]> wrote:
>
> Laryn:
> 
> Take a look at: http://www.apc.com/products/family/index.cfm?id=14
 
> 
> This would do exactly what you want. Don't bother with the new 
> (Especially at $400), I have an older version picked up off of Ebay
here 
> at the house and it runs great.
> Protects against the UPS failing, and since it's got a network 
> connection I can log into it remotely and actually see the log of when 
> power dropped out on either side.
> 
> Chuck n0nhj
> 
> 
> Laryn Lohman wrote:
> > Thanks for the great posts so far.
> >
> > Perhaps I didn't make it clear in my original post--our equipment is
> > and always has been plugged into the red receptacle. It was installed
> > by hospital electricians a number of years ago for us, and we are the
> > sole load on the circuit. It was the recent storm, and presumed
> > lightning strike, that tripped the AC breaker in the emergency breaker
> > panel in the penthouse where our stuff is.
> >
> > The point of all this is that the breaker tripped, leaving our
> > equipment with no power . So I was proposing a method of
> > implementing a "backup breaker" in case one breaker trips. My
> > proposal is that our normal, daily supply would be the white
> > receptacle. If it goes dead, whether from utility failure or breaker
> > trip, we have the red receptacle, which will then be ready to feed our
> > stuff.
> >
> > The reason we would not want to be on the red receptacle normally is
> > that in case of a lightning strike we are potentially left with a dead
> > red from the strike, and dead white if the utility is down. 
> > Obviously, another strike, after we've switched to the red, kills AC
> > totally to our stuff. The presumption is that a breaker probably
> > won't trip, even after a strike, if there's not a load of some sort on
> > it to complete a path for the "tripping" current. Make sense?
> >
> > Eric, I think you're on my line of thinking. Good point on keeping
> > the greens isolated.
> >
> > Laryn K8TVZ
> >
> >
> >
> >
> > 
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>



 

Re: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

[Chuck Kimball]

Laryn:

Take a look at:  http://www.apc.com/products/family/index.cfm?id=14

This would do exactly what you want.  Don't bother with the new 
(Especially at $400), I have an older version picked up off of Ebay here 
at the house and it runs great.
Protects against the UPS failing, and since it's got a network 
connection I can log into it remotely and actually see the log of when 
power dropped out on either side.

Chuck  n0nhj


Laryn Lohman wrote:
> Thanks for the great posts so far.
>
> Perhaps I didn't make it clear in my original post--our equipment is
> and always has been plugged into the red receptacle.  It was installed
> by hospital electricians a number of years ago for us, and we are the
> sole load on the circuit.  It was the recent storm, and presumed
> lightning strike, that tripped the AC breaker in the emergency breaker
> panel in the penthouse where our stuff is.
>
> The point of all this is that the breaker tripped, leaving our
> equipment with no power .  So I was proposing a method of
> implementing a "backup breaker" in case one breaker trips.  My
> proposal is that our normal, daily supply would be the white
> receptacle.  If it goes dead, whether from utility failure or breaker
> trip, we have the red receptacle, which will then be ready to feed our
> stuff.
>
> The reason we would not want to be on the red receptacle normally is
> that in case of a lightning strike we are potentially left with a dead
> red from the strike, and dead white if the utility is down. 
> Obviously, another strike, after we've switched to the red, kills AC
> totally to our stuff.  The presumption is that a breaker probably
> won't trip, even after a strike, if there's not a load of some sort on
> it to complete a path for the "tripping" current.  Make sense?
>
> Eric, I think you're on my line of thinking.  Good point on keeping
> the greens isolated.
>
> Laryn K8TVZ
>
>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>
>
>   

Re: Re: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

[Ron Wright]

Kris,

I think you need to read the initial and follow up postings.

It is thought that if either the normally used white outlet and/or unused RED 
outlet were not in use at the time of the lightning strike it would not have 
tripped their breaker.  So it is thought if the breaker that was to the outlet  
was in use and got hit and braker tripped then something would switch over to 
the other unused RED emergency powered outlet.

If lightning did hit the relay or anything else it will do as it wants.

The posting of using a UPS after a relay switch appeals to me.  This way when 
there was switching between the sources the UPS could buffer the short loss of 
power and the repeaters and other equipment would not see a change.  Also the 
UPS would have to maintain power for short period of time and could be lower VA 
unit, possible 500 VA. Most UPSs have surge and some lightning protection.

73, ron, n9ee/r


>From: Kris Kirby <[EMAIL PROTECTED]>
>Date: 2008/07/14 Mon AM 11:41:00 EDT
>To: Repeater-Builder@yahoogroups.com
>Subject: Re: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

>
>On Mon, 14 Jul 2008, Laryn Lohman wrote:
>> The reason we would not want to be on the red receptacle normally is 
>> that in case of a lightning strike we are potentially left with a dead 
>> red from the strike, and dead white if the utility is down. Obviously, 
>> another strike, after we've switched to the red, kills AC totally to 
>> our stuff.  The presumption is that a breaker probably won't trip, 
>> even after a strike, if there's not a load of some sort on it to 
>> complete a path for the "tripping" current.  Make sense?
>
>We're talking about an ionized channel of electrons that can cross 
>hundreds of feet vertically, and still generate smaller channels within 
>the radio shed that can jump a foot or more. Do you really think that a 
>3PDT relay with contacts one quarter of an inch apart represents an 
>obstacle for this immense charge of electricity? I understand that you 
>want to get it back on the air yesterday, but unless you've implemented 
>a lightning arrestor on every bloody port of every bloody device, I 
>wouldn't bet that you could keep the breaker from tripping. 
>
>--
>Kris Kirby, KE4AHR  <[EMAIL PROTECTED]>
>But remember, with no superpowers comes no responsibility. 
>   --rly
>   
> 


Ron Wright, N9EE
727-376-6575
MICRO COMPUTER CONCEPTS
Owner 146.64 repeater Tampa Bay, FL
No tone, all are welcome.

Re: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

[Kris Kirby]

On Mon, 14 Jul 2008, Laryn Lohman wrote:
> The reason we would not want to be on the red receptacle normally is 
> that in case of a lightning strike we are potentially left with a dead 
> red from the strike, and dead white if the utility is down. Obviously, 
> another strike, after we've switched to the red, kills AC totally to 
> our stuff.  The presumption is that a breaker probably won't trip, 
> even after a strike, if there's not a load of some sort on it to 
> complete a path for the "tripping" current.  Make sense?

We're talking about an ionized channel of electrons that can cross 
hundreds of feet vertically, and still generate smaller channels within 
the radio shed that can jump a foot or more. Do you really think that a 
3PDT relay with contacts one quarter of an inch apart represents an 
obstacle for this immense charge of electricity? I understand that you 
want to get it back on the air yesterday, but unless you've implemented 
a lightning arrestor on every bloody port of every bloody device, I 
wouldn't bet that you could keep the breaker from tripping. 

--
Kris Kirby, KE4AHR  <[EMAIL PROTECTED]>
But remember, with no superpowers comes no responsibility. 
--rly

Re: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

[Ron Wright]

Laryn,

As recommended by Eric, I and others a relay would be simple thing to do using 
the normal outlet until it failed and then automatically switch over to the RED 
outlet.

I am sure one could come up with a complex way of doing it with some good 
reasons, but a simple 3 pole/double throw relay being powered from the normal 
white outlet would work with you not having to worry about tripping the RED 
breaker under normal use.

If 40 years ago we would suggest you put a penny in the fuse socket, hi.  Back 
then you could probably get away with it, but today just doing it would get 
your repeater tossed into the next county.  That is what we need...panel 
circuit breakers with penny slots.

73, ron, n9ee/r




>From: Laryn Lohman <[EMAIL PROTECTED]>
>Date: 2008/07/13 Sun PM 11:57:05 EDT
>To: Repeater-Builder@yahoogroups.com
>Subject: [Repeater-Builder] Re: Switching a Repeater Betwen AC Sources

>
>Thanks for the great posts so far.
>
>Perhaps I didn't make it clear in my original post--our equipment is
>and always has been plugged into the red receptacle.  It was installed
>by hospital electricians a number of years ago for us, and we are the
>sole load on the circuit.  It was the recent storm, and presumed
>lightning strike, that tripped the AC breaker in the emergency breaker
>panel in the penthouse where our stuff is.
>
>The point of all this is that the breaker tripped, leaving our
>equipment with no power .  So I was proposing a method of
>implementing a "backup breaker" in case one breaker trips.  My
>proposal is that our normal, daily supply would be the white
>receptacle.  If it goes dead, whether from utility failure or breaker
>trip, we have the red receptacle, which will then be ready to feed our
>stuff.
>
>The reason we would not want to be on the red receptacle normally is
>that in case of a lightning strike we are potentially left with a dead
>red from the strike, and dead white if the utility is down. 
>Obviously, another strike, after we've switched to the red, kills AC
>totally to our stuff.  The presumption is that a breaker probably
>won't trip, even after a strike, if there's not a load of some sort on
>it to complete a path for the "tripping" current.  Make sense?
>
>Eric, I think you're on my line of thinking.  Good point on keeping
>the greens isolated.
>
>Laryn K8TVZ
>
>   
> 


Ron Wright, N9EE
727-376-6575
MICRO COMPUTER CONCEPTS
Owner 146.64 repeater Tampa Bay, FL
No tone, all are welcome.