> More to the point, as I note in another reply, you don't want to be *the
> lineman
> down the road with his hands on a "dead" wire*.
>
> Pretty much the *first paragraph* in NEC 700 (700.6) says this:
>
> """
> Transfer equipment shall be designed and installed to prevent the inadvertent
> int
On Jun 25, 2011, at 4:59 PM, Joel Jaeggli wrote:
>
> On Jun 25, 2011, at 4:47 PM, Andrew D Kirch wrote:
>
>> On 6/25/2011 7:43 PM, Paul Graydon wrote:
>>> Take a guess what the datacenter our equipment is currently hosted in uses.
>>> Yet another reason to be glad of a datacenter move that's
On 6/27/11 1:19 PM, Matthew Black wrote:
On Fri, 24 Jun 2011 18:29:14 -0400
Jay Ashworth wrote:
The North American Electric Reliability Council is planning to relax
the standards for how closely power utilities must hold to 60.00Hz.
Here's my absolute favorite quote of all time:
Tweaking th
On Fri, 24 Jun 2011 18:29:14 -0400
Jay Ashworth wrote:
The North American Electric Reliability Council is planning to relax
the standards for how closely power utilities must hold to 60.00Hz.
Here's my absolute favorite quote of all time:
Tweaking the power grid's frequency is expensive and
On Sun, Jun 26, 2011 at 06:46:09PM -0400, Pete Carah wrote:
> HVAC compressors have their own problems; once fully stopped you have
> to wait for the liquid to clear the compressor before restarting, or
> have LOTS of torque (like a car unit) available (and a supply of new
> belts :-)
[begin OT le
Hi,
Yes, transforming DC is not easy.
However, DC works good at long haul transmission because a lot of energy is
lost in the revers EMF generated by AC a several hundred volts. Some years ago
a high voltage DC line was constructed between Oregon and California to deliver
power to California.
On 06/26/2011 05:55 PM, Jussi Peltola wrote:
> On Sun, Jun 26, 2011 at 11:36:24PM +0200, Ingo Flaschberger wrote:
>> but transforming is not easy.
>> ac/ac transformers are easy tu build and very immune against lightning
>> strikes - inverter systems are not.
> Switching DC is also problematic si
On 06/26/2011 05:43 PM, Ingo Flaschberger wrote:
>> 2) Allowing transformer fields to collapse. Even in phase, without a
>> delayed transition ATS you can end up with a partially collapsed
>> transformer field with a new field being created at non-ground state.
>> This can cause a transient back wa
On Sun, Jun 26, 2011 at 11:36:24PM +0200, Ingo Flaschberger wrote:
> but transforming is not easy.
> ac/ac transformers are easy tu build and very immune against lightning
> strikes - inverter systems are not.
Switching DC is also problematic since there is no zero crossing to
extinguish the arc
2) Allowing transformer fields to collapse. Even in phase, without a
delayed transition ATS you can end up with a partially collapsed
transformer field with a new field being created at non-ground state.
This can cause a transient back wave that can snap circuit breakers.
Yep, this one happened
Take a guess what the datacenter our equipment is currently hosted in uses.
Yet another reason to be glad of a datacenter move that's coming up.
Why can't we just all use DC and be happy?
motors don't produce DC?
dc generators produce dc.
tesla vs edison?
human safe dc voltage requires
> It makes little sense to sync to the grid when the generator is only
> used when the grid is down
I don't know what large DC do but at our large sites we normally get
power cheaper in exchange for a load shed agreement.
When we got the call we ran some/all of the load on generator so the
grid c
- Original Message -
> From: "Jeff Wheeler"
> On Sun, Jun 26, 2011 at 12:23 AM, Alex Rubenstein
> wrote:
> > At least here in JCPL territory (northern NJ), closed transition is
> > frowned upon. Too much risk, they think. They are correct, really,
> > but the risk is mostly yours. If you
- Original Message -
> From: "Michael DeMan"
> It is my understanding also that most commercial grade gensets have
> built into the ATS logic that when utility power comesback online,
> that the transfer back to utility power is coordinated with the ATS
> driving the generator until both
Yep, this one happened to us a few times
before we switched to a delayed ATS, was a PITA to debug and resolve.
-Original Message-
From: Seth Mattinen [mailto:se...@rollernet.us]
Sent: Saturday, June 25, 2011 8:49 PM
To: nanog@nanog.org
Subject: Re: Wacky Weekend: NERC to relax power grid
> I think we're missing something, which is where these ATS's are
> installed.
>
> I don't think most utilities allow (largeish) ATS's to do a closed
> transition from a genset to the utility grid, but I may be wrong.
> There may be other ATS's in your facility that do a closed transition
> though
> It makes little sense to sync to the grid when the generator is only
> used when the grid is down - and unless you run your generators 24/7
> your UPS will have to make up for the comparatively long time it takes
> for the generator to start, so it's rather useless to sync the
> generator when th
On Sun, Jun 26, 2011 at 05:27:10AM -0700, Leo Bicknell wrote:
> It's not that you couldn't install a closed transition ATS in the
> ATS 1a/1b location from an electrical point of view, but I don't
> think codes, power companies, or common sense make it a good idea.
> As others have pointed out, the
In a message written on Sat, Jun 25, 2011 at 03:32:09PM -0700, Seth Mattinen
wrote:
> Most of these come in open, delayed, or closed transition models:
> http://www.gedigitalenergy.com/powerquality/ATSHome.htm
I think we're missing something, which is where these ATS's are
installed.
I don't thi
On Sun, Jun 26, 2011 at 12:23 AM, Alex Rubenstein wrote:
> At least here in JCPL territory (northern NJ), closed transition is frowned
> upon. Too much risk, they think. They are correct, really, but the risk is
> mostly yours. If you lock to the utility out-of-phase, you will surely lose
> and
> It ismy understanding also that most commercial grade gensets have
> built into the ATS logic that when utility power comesback online, that
> the transfer back to utility power is coordinated with the ATS driving
> the generator until both frequency and phases are within a user
> specified rang
On Jun 25, 2011, at 4:47 PM, Andrew D Kirch wrote:
> On 6/25/2011 7:43 PM, Paul Graydon wrote:
>> Take a guess what the datacenter our equipment is currently hosted in uses.
>> Yet another reason to be glad of a datacenter move that's coming up.
>>
> Why can't we just all use DC and be happy
It ismy understanding also that most commercial grade gensets have built into
the ATS logic that when utility power comesback online, that the transfer back
to utility power is coordinated with the ATS driving the generator until both
frequency and phases are within a user specified range?
- mi
- Original Message -
> From: "Seth Mattinen"
> On 6/25/2011 15:12, Leo Bicknell wrote:
> > I have never seen a generator that syncs to the utility for live, no
> > break transfer. I'm sure such a thing exists, but that sounds crazy
> > dangerous to me. Generators sync to each other, not t
On 6/25/2011 16:43, Paul Graydon wrote:
> On 6/25/2011 12:32 PM, Seth Mattinen wrote:
>>
>> For open and closed transitions you'll most certainly want to sync to
>> utility to transition between the two. For the delayed transition model
>> it'll stop at the intermediate "open" point for a configura
On Jun 25, 2011, at 4:47 PM, Andrew D Kirch wrote:
> On 6/25/2011 7:43 PM, Paul Graydon wrote:
>> Take a guess what the datacenter our equipment is currently hosted in uses.
>> Yet another reason to be glad of a datacenter move that's coming up.
>>
> Why can't we just all use DC and be happy?
On 6/25/2011 7:43 PM, Paul Graydon wrote:
Take a guess what the datacenter our equipment is currently hosted in
uses. Yet another reason to be glad of a datacenter move that's
coming up.
Why can't we just all use DC and be happy?
On 6/25/2011 12:32 PM, Seth Mattinen wrote:
On 6/25/2011 15:12, Leo Bicknell wrote:
I have never seen a generator that syncs to the utility for live, no
break transfer. I'm sure such a thing exists, but that sounds crazy
dangerous to me. Generators sync to each other, not the utility.
Most o
Generators all stay in sync. Generator owners have expensive devices
that sync the phase before the generator is connected to the grid. Once
a generator is connected to the gird, it will stay in sync - in fact
that is why they have the expensive devices to make sure that they are
in sync before
On 6/25/2011 15:12, Leo Bicknell wrote:
>
> I have never seen a generator that syncs to the utility for live, no
> break transfer. I'm sure such a thing exists, but that sounds crazy
> dangerous to me. Generators sync to each other, not the utility.
>
Most of these come in open, delayed, or clo
In a message written on Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashworth
wrote:
> I believe the answer to that question is contained here:
>
> http://yarchive.net/car/rv/generator_synchronization.html [1]
I wouldn't use a colo that had to sync their generator to the grid.
That is a bad desi
On 06/25/2011 03:52 PM, Jason Roysdon wrote:
> On 06/25/2011 08:06 AM, William Herrin wrote:
>> On Sat, Jun 25, 2011 at 10:49 AM, Jay Ashworth wrote:
>>> Perhaps I read the piece incorrectly, but it certainly sounded to *me* like
>>> the part that was hard was not hitting 60.00, but *staying in sy
On 06/25/2011 02:02 PM, Jay Ashworth wrote:
> - Original Message -
>> From: "Jason Roysdon"
>
>> That's what they're doing here, opting to skip "patching" the time
>> error. They're not ignoring frequency altogether, but rather only
>> minding that aspects that have to do with grid stabi
- Original Message -
> From: "Jason Roysdon"
> That's what they're doing here, opting to skip "patching" the time
> error. They're not ignoring frequency altogether, but rather only
> minding that aspects that have to do with grid stability, not your alarm
> clock. This is for the better
On 06/25/2011 08:06 AM, William Herrin wrote:
> On Sat, Jun 25, 2011 at 10:49 AM, Jay Ashworth wrote:
>> Perhaps I read the piece incorrectly, but it certainly sounded to *me* like
>> the part that was hard was not hitting 60.00, but *staying in sync with
>> others*...
>
> Way I read it, when th
On Jun 25, 2011, at 11:03 AM, Jason Roysdon wrote:
>
> On 06/25/2011 07:49 AM, Jay Ashworth wrote:
>> - Original Message -
>>> From: "Jussi Peltola"
>>
>>> On Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashworth wrote:
This is gonna be fun, no?
>>>
>>> If your definition of fun is
On 06/25/2011 07:49 AM, Jay Ashworth wrote:
> - Original Message -
>> From: "Jussi Peltola"
>
>> On Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashworth wrote:
>>> This is gonna be fun, no?
>>
>> If your definition of fun is spending a year watching an old microwave
>> clock lose or gain
On Sat, Jun 25, 2011 at 10:49 AM, Jay Ashworth wrote:
> Perhaps I read the piece incorrectly, but it certainly sounded to *me* like
> the part that was hard was not hitting 60.00, but *staying in sync with
> others*...
Way I read it, when they occasionally run at 59.9hz for a few hours
(and accor
- Original Message -
> From: "Jussi Peltola"
> On Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashworth wrote:
> > This is gonna be fun, no?
>
> If your definition of fun is spending a year watching an old microwave
> clock lose or gain a few minutes.
>
> I don't see how this has anything
On Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashworth wrote:
> This is gonna be fun, no?
If your definition of fun is spending a year watching an old microwave
clock lose or gain a few minutes.
I don't see how this has anything to do with syncing two generators. The
grid is in sync, and if the
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