Elecraft

[OT} Whole House Surge Protection

Classic

List

Threaded

16 messages Options

K7TV

[OT} Whole House Surge Protection

I am aware that the surge protected power strips I use are poor protection,
because the shack uses more than one circuit from the panel, and I also have
one power strip chained from another. The solution, I understand, is whole
house surge protection located at the service entrance. I am currently very
busy building a room addition to the house. This includes electrical
installation work, and I had the idea of getting whole house surge
protection installed at the same time.

Busy as I was, I didn't take enough time to make sure to buy the correct
unit. My house has a kind of 3-phase system called "Split Phase High Leg
Delta". This system adds a 3rd phase to the residential wiring that normally
doesn't have it. The purpose in my case is for a 3-phase air conditioner.
With this system, the 3rd leg coming into the panel has a higher voltage,
208 V, relative to the neutral. Not taking this into account I bought a
protector Leviton 51120-3 that is designed for regular 3-phase wiring,
which has only 120 V between each phase and neutral. I believe if I hooked
it up to all 3 phases coming into the panel, it would fry the protector.

I have now identified another protector 32412-DS3 from Leviton that I
believe is right for my application. It costs about $600 vs. only $225 for
the one I bought. There is another difference. The one I bought includes a
warranty not only for the device but also for a high dollar amount worth of
electronics such as ham gear. The unit I should have bought has a warranty
only for the device itself and not for connected electronics.

My questions for the group: Do you have whole house surge protection
installed, especially with a high leg electrical system? If so, what
particular device did you install? Is there any manufacturer out there that
offers a protector for high leg installations with a warranty that covers
connected electronics? Maybe at a price better than $600? I plan to put the
unit I bought up for sale and hope to get $150 (never hooked up, still in
shrinkwrap). However, another possibility comes to mind. The electrical
service panel where I intend to install the new protector actually feeds
another older panel inside the house that runs the older wiring, including
most of the shack. Would it make sense to install the unit at the old panel
instead of selling it? The benefit would be added protecton for ham
equipment, but I see two reasons not to do it. First, this 3-phase protector
would be wired up to only 2 phases at the old panel, and that means it would
not be installed per the instructions, so that warranty of connected
equipment would be voided. Second, my linear and a few smaller ham devices
are fed from a newer circuit from the main panel, bypassing the old panel. I
concluded earlier that this situation will make the protection in the power
strips useless. I also believe it would make a protector located at the old
panel useless. So I am pretty sure I should sell the protector I bought. It
is too late to return it to the vendor.

Thanks in advance for any advice.

73,

Erik K7TV

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

David Gilbert

Re: [OT} Whole House Surge Protection

Delta 3-phase systems are most definitely NOT compatible with Y-connect
3-phase systems, so you are completely correct on that point.

One other point, though. I'm pretty sure that any such surge
protectors are not intended to be used for lightning protection ... just
is case that is one of your motivations for installing one. The fine
print on the whole house system offered by my electric utility
specifically exempts lightning surges from protection.

73,
Dave AB7E

On 1/31/2013 4:42 PM, Erik Basilier wrote:

> I am aware that the surge protected power strips I use are poor protection,
> because the shack uses more than one circuit from the panel, and I also have
> one power strip chained from another. The solution, I understand, is whole
> house surge protection located at the service entrance. I am currently very
> busy building a room addition to the house. This includes electrical
> installation work, and I had the idea of getting whole house surge
> protection installed at the same time.
>
>
>
> Busy as I was, I didn't take enough time to make sure to buy the correct
> unit. My house has a kind of 3-phase system called "Split Phase High Leg
> Delta". This system adds a 3rd phase to the residential wiring that normally
> doesn't have it. The purpose in my case is for a 3-phase air conditioner.
> With this system, the 3rd leg coming into the panel has a higher voltage,
> 208 V, relative to the neutral. Not taking this into account I bought a
> protector Leviton 51120-3 that is designed for regular 3-phase wiring,
> which has only 120 V between each phase and neutral. I believe if I hooked
> it up to all 3 phases coming into the panel, it would fry the protector.
>
>
>
> I have now identified another protector 32412-DS3 from Leviton that I
> believe is right for my application. It costs about $600 vs. only $225 for
> the one I bought. There is another difference. The one I bought includes a
> warranty not only for the device but also for a high dollar amount worth of
> electronics such as ham gear. The unit I should have bought has a warranty
> only for the device itself and not for connected electronics.
>
>
>
> My questions for the group: Do you have whole house surge protection
> installed, especially with a high leg electrical system? If so, what
> particular device did you install? Is there any manufacturer out there that
> offers a protector for high leg installations with a warranty that covers
> connected electronics? Maybe at a price better than $600? I plan to put the
> unit I bought up for sale and hope to get $150 (never hooked up, still in
> shrinkwrap). However, another possibility comes to mind. The electrical
> service panel where I intend to install the new protector actually feeds
> another older panel inside the house that runs the older wiring, including
> most of the shack. Would it make sense to install the unit at the old panel
> instead of selling it? The benefit would be added protecton for ham
> equipment, but I see two reasons not to do it. First, this 3-phase protector
> would be wired up to only 2 phases at the old panel, and that means it would
> not be installed per the instructions, so that warranty of connected
> equipment would be voided. Second, my linear and a few smaller ham devices
> are fed from a newer circuit from the main panel, bypassing the old panel. I
> concluded earlier that this situation will make the protection in the power
> strips useless. I also believe it would make a protector located at the old
> panel useless. So I am pretty sure I should sell the protector I bought. It
> is too late to return it to the vendor.
>
>
>
> Thanks in advance for any advice.
>
>
>
> 73,
>
> Erik K7TV
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

mcduffie

Re: [OT} Whole House Surge Protection

In reply to this post by K7TV

On Thu, 31 Jan 2013 16:42:04 -0700, Erik Basilier wrote:

Erik,

> My questions for the group: Do you have whole house surge protection
> installed, especially with a high leg electrical system?

My answer won't help you a bit, because, as you already know, you have
an abnormal installation.

However, I do use whole house and I use more than one. There is one at
the entrance where the buried cable comes out of the ground and enters
the house. There is a second one at the old entrance that is fed
directly by the new underground entrance via long line. Third, there is
another one located at the shack 230 line that I ran from the old
entrance when I first bought the house. All of these units are standard
220-0-220 units, none are poly-phase.

I've been using them for some 40 years. A tidbit of info for you.
General Electric units used to cost $30 each. I was charged over $120
for the last one I bought. When I questioned it, I was told that the
prices shot up when the marketing department got hold of the product.
That was many years ago.

I paid no attention to the warranty. I don't expect them to do a thing
about it if there is any damage. I just bought the best protection I
could afford at the time. I wouldn't pay today's prices you quote.
Insurance is cheaper.

> Would it make sense to install the unit at the old panel
> instead of selling it?

It does to me, but then I am not worried about the wording of the
warranty, and I don't have a poly-phase installation where voltages are
odd.

All of the above is my OPINION, and could be incorrect technically.
YMMV.

Gary
--
http://ag0n.net
3055: http://ag0n.net/irlp/3055
NodeOp Help Page: http://ag0n.net/irlp
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Don Wilhelm-4

Re: [OT} Whole House Surge Protection

In reply to this post by K7TV

I cannot comment on your particular 'high-leg' entry system - mine is
plain vanilla 240 volt single phase with neutral.

I can only speak from my experience. I have an entry panel surge
protection device in my power entrance panel. I also use local surge
protectors (Tripplite) at the ham station, and the computers have UPSs
that offer surge protection. All the hamshack runs off the same AC
receptacle.

We had a close lightning event last summer and there were no incidences
of damage on the AC side, although all the GFCI breakers tripped.

The wired Ethernet devices were not so fortunate, I lost a router, 2 8
port switches, an access point, a NAS storage device, and 4 computers
after that event, that did not mention the Ethernet connected network
printer that lost its Ethernet capability, but still worked with a USB
connection - all apparently due to the surge coming in over the Ethernet
cables. Fortunately, no data was lost, the devices did not work due to
damaged network ports.

So the AC protection did work, but the unprotected Ethernet devices did
not survive.

The 'whole house' protection did work.

73,
Don W3FPR

On 1/31/2013 6:42 PM, Erik Basilier wrote:

Jim Brown-10

Re: [OT} Whole House Surge Protection

On 1/31/2013 4:26 PM, Don Wilhelm wrote:

> We had a close lightning event last summer and there were no
> incidences of damage on the AC side, although all the GFCI breakers
> tripped.
>
> The wired Ethernet devices were not so fortunate, I lost a router, 2 8
> port switches, an access point, a NAS storage device, and 4 computers
> after that event, that did not mention the Ethernet connected network
> printer that lost its Ethernet capability, but still worked with a USB
> connection - all apparently due to the surge coming in over the
> Ethernet cables. Fortunately, no data was lost, the devices did not
> work due to damaged network ports.
>
> So the AC protection did work, but the unprotected Ethernet devices
> did not survive.

The so-called surge protectors on your computers is what CAUSED your
Ethernet devices to fry. Shunt mode (MOV) protectors on branch circuits
are a REALLY bad idea.

MOVs at the service entrance are a very GOOD thing -- IF the house is
properly grounded.

The "high leg delta" is simply three Delta-connected transfomers on the
pole, one of which is center-tapped. There's 240V between legs, and if
you have 3-phase service from high-leg Delta, you get all three phases.
Customers who buy single-phase service (99.9% of homes) get both sides
of the center-tapped transformer and the neutral.

The (really) bad part of this is that ALL 3-phase systems have lots of
harmonic current, AND the single-phase get a super heavy dose of that
harmonic current on their neutral, which is the only path to ground for
it. THAT'S where "ground buzz" comes from.

A "whole house" surge protector has two BIG MOVs, one connected from the
two sides of the 120-0-120 to neutral, which is bonded to ground in the
entrance panel. For a 3-phase system, you simply need a protector with
one more MOV.

BTW -- the system I've described is called "high leg Delta" (also "wild
leg" or "red leg") because the terminal of the 3-phase system opposite
the transformer is 277V to neutral.

There's a discussion of all of this in the Power and Grounding tutorial
on my website. http://audiosystemsgroup.com/publish.htm Although it's
written for audio and video professionals, everything in it applies
equally to installations of all sorts, including radio.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Richard Fjeld

Re: [OT} Whole House Surge Protection

In reply to this post by Don Wilhelm-4

We used to discuss this topic at work. Someone brought out the fact that a power strip or some other device with a surge protector built in should cover everything on that particular leg. It's a parallel circuit. (I'm not defending this).

Also, it was brought out that MOV surge protectors are for a very short duration spike, of which lightning is not. Many have a fuse in series with the MOV for that reason. While this may come across as negative, surge protectors have their place.

Back, circa late 70's- 80's, a momentary open on the power caused a high voltage spike on the AC. It took out hundreds, or more, TV's and Ham Radio electronics in that neighborhood. I built a box with an AC relay that locks up through it's own contacts. I have two outlet boxes attached to it. I have a momentary button to bring the relay up, and one to release it. If a 'hit' should occur on the power the relay will release and open the AC circuit to my equipment. Should the AC restore with high voltage, my equipment plugged into it will not be connected. I have a UPS to feed my K3 power supply so I can shut the K3 down normally.

Rich, n0ce

----- Original Message -----
From: Don Wilhelm
To: Erik Basilier
Cc: [hidden email]
Sent: Thursday, January 31, 2013 6:26 PM
Subject: Re: [Elecraft] [OT} Whole House Surge Protection

I cannot comment on your particular 'high-leg' entry system - mine is
plain vanilla 240 volt single phase with neutral.

I can only speak from my experience. I have an entry panel surge
protection device in my power entrance panel. I also use local surge
protectors (Tripplite) at the ham station, and the computers have UPSs
that offer surge protection. All the hamshack runs off the same AC
receptacle.

We had a close lightning event last summer and there were no incidences
of damage on the AC side, although all the GFCI breakers tripped.

The wired Ethernet devices were not so fortunate, I lost a router, 2 8
port switches, an access point, a NAS storage device, and 4 computers
after that event, that did not mention the Ethernet connected network
printer that lost its Ethernet capability, but still worked with a USB
connection - all apparently due to the surge coming in over the Ethernet
cables. Fortunately, no data was lost, the devices did not work due to
damaged network ports.

So the AC protection did work, but the unprotected Ethernet devices did
not survive.

The 'whole house' protection did work.

73,
Don W3FPR

On 1/31/2013 6:42 PM, Erik Basilier wrote:
> I am aware that the surge protected power strips I use are poor protection,
> because the shack uses more than one circuit from the panel, and I also have
> one power strip chained from another. The solution, I understand, is whole
> house surge protection located at the service entrance. I am currently very
> busy building a room addition to the house. This includes electrical
> installation work, and I had the idea of getting whole house surge
> protection installed at the same time.
>
>
>
> Busy as I was, I didn't take enough time to make sure to buy the correct
> unit. My house has a kind of 3-phase system called "Split Phase High Leg
> Delta". This system adds a 3rd phase to the residential wiring that normally
> doesn't have it. The purpose in my case is for a 3-phase air conditioner.
> With this system, the 3rd leg coming into the panel has a higher voltage,
> 208 V, relative to the neutral. Not taking this into account I bought a
> protector Leviton 51120-3 that is designed for regular 3-phase wiring,
> which has only 120 V between each phase and neutral. I believe if I hooked
> it up to all 3 phases coming into the panel, it would fry the protector.
>
>
>
> I have now identified another protector 32412-DS3 from Leviton that I
> believe is right for my application. It costs about $600 vs. only $225 for
> the one I bought. There is another difference. The one I bought includes a
> warranty not only for the device but also for a high dollar amount worth of
> electronics such as ham gear. The unit I should have bought has a warranty
> only for the device itself and not for connected electronics.
>
>
>
> My questions for the group: Do you have whole house surge protection
> installed, especially with a high leg electrical system? If so, what
> particular device did you install? Is there any manufacturer out there that
> offers a protector for high leg installations with a warranty that covers
> connected electronics? Maybe at a price better than $600? I plan to put the
> unit I bought up for sale and hope to get $150 (never hooked up, still in
> shrinkwrap). However, another possibility comes to mind. The electrical
> service panel where I intend to install the new protector actually feeds
> another older panel inside the house that runs the older wiring, including
> most of the shack. Would it make sense to install the unit at the old panel
> instead of selling it? The benefit would be added protecton for ham
> equipment, but I see two reasons not to do it. First, this 3-phase protector
> would be wired up to only 2 phases at the old panel, and that means it would
> not be installed per the instructions, so that warranty of connected
> equipment would be voided. Second, my linear and a few smaller ham devices
> are fed from a newer circuit from the main panel, bypassing the old panel. I
> concluded earlier that this situation will make the protection in the power
> strips useless. I also believe it would make a protector located at the old
> panel useless. So I am pretty sure I should sell the protector I bought. It
> is too late to return it to the vendor.
>
>
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Mark Bayern

Re: [OT} Whole House Surge Protection

> We used to discuss this topic at work. Someone brought out the fact that a power strip or some other device with a surge protector built in should cover everything on that particular leg. It's a parallel circuit. (I'm not defending this).

You're right in not defending that stance. It might cover everything
on that leg if_and_only_if the leg in question was an ideal conductor
and was immune to EM fields. Real life wiring just doesn't work that
way.

Mark AD5SS

On Fri, Feb 1, 2013 at 11:59 AM, Richard Fjeld <[hidden email]> wrote:
> We used to discuss this topic at work. Someone brought out the fact that a power strip or some other device with a surge protector built in should cover everything on that particular leg. It's a parallel circuit. (I'm not defending this).
>
> Also, it was brought out that MOV surge protectors are for a very short duration spike, of which lightning is not. Many have a fuse in series with the MOV for that reason. While this may come across as negative, surge protectors have their place.
>
> Back, circa late 70's- 80's, a momentary open on the power caused a high voltage spike on the AC. It took out hundreds, or more, TV's and Ham Radio electronics in that neighborhood. I built a box with an AC relay that locks up through it's own contacts. I have two outlet boxes attached to it. I have a momentary button to bring the relay up, and one to release it. If a 'hit' should occur on the power the relay will release and open the AC circuit to my equipment. Should the AC restore with high voltage, my equipment plugged into it will not be connected. I have a UPS to feed my K3 power supply so I can shut the K3 down normally.
>
> Rich, n0ce
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Jim Brown-10

Re: [OT} Whole House Surge Protection

On 2/1/2013 10:21 AM, Mark Bayern wrote:
> Someone brought out the fact that a power strip or some other device with a surge protector built in should cover everything on that particular leg. It's a parallel circuit.

Nope. ANY shunt mode device (MOV) operates by conducting the spike to
the green wire or the neutral. The resulting current raises the voltage
on the green wire (which is connected to the chassis of the equipment
plugged into the "protected" outlet) to some very high value, depending
on the spike that sets it off. In the case of lightning, this can be a lot.

Now, consider equipment connected to two different power strips, with or
without an MOV, or to different locations, or to another ground. ALL of
those other points will be at a different potential as a result of
seeing the same spike, and again, in the case of lightning, that can be
a VERY large difference. it is the DIFFERENCE in potential from one
piece of gear to the other that fries those Ethernet ports, and it would
also fry signal interconnect circuitry for audio and video.

THIS is why MOVs are a really bad idea on branch circuits. Those of us
working in pro audio have LOTS of interconnected equipment, often at
widely separated points, so we learned all of this the hard way nearly
20 years ago. Our solution has been to use SERIES-MODE Surge Protectors,
and that has been quite effective. SurgeX and Brick Wall are the only
two companies I know of that have licensed the series mode patent. Their
products are not cheap, but they work. I have SurgeX protectors on all
of my ham gear, computers, and audio/video gear.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Alan Bloom

Re: [OT} Whole House Surge Protection

The problem is it is getting hard to find decent-quality outlet strips
that DON'T have surge protection built in. I am currently building up a
second studio for KBBF-FM, a community bi-lingual station here in Santa
Rosa. I wanted an outlet strip with some sockets spaced far enough
apart to accommodate several wall transformers. I found the perfect
device at Home Depot, but it has surge protection built in.

Should I crack it open and remove the MOVs?

Alan N1AL

On 2/1/2013 12:02 PM, Jim Brown wrote:

> On 2/1/2013 10:21 AM, Mark Bayern wrote:
>> Someone brought out the fact that a power strip or some other device
>> with a surge protector built in should cover everything on that
>> particular leg. It's a parallel circuit.
>
> Nope. ANY shunt mode device (MOV) operates by conducting the spike to
> the green wire or the neutral. The resulting current raises the voltage
> on the green wire (which is connected to the chassis of the equipment
> plugged into the "protected" outlet) to some very high value, depending
> on the spike that sets it off. In the case of lightning, this can be a lot.
>
> Now, consider equipment connected to two different power strips, with or
> without an MOV, or to different locations, or to another ground. ALL of
> those other points will be at a different potential as a result of
> seeing the same spike, and again, in the case of lightning, that can be
> a VERY large difference. it is the DIFFERENCE in potential from one
> piece of gear to the other that fries those Ethernet ports, and it would
> also fry signal interconnect circuitry for audio and video.
>
> THIS is why MOVs are a really bad idea on branch circuits. Those of us
> working in pro audio have LOTS of interconnected equipment, often at
> widely separated points, so we learned all of this the hard way nearly
> 20 years ago. Our solution has been to use SERIES-MODE Surge Protectors,
> and that has been quite effective. SurgeX and Brick Wall are the only
> two companies I know of that have licensed the series mode patent. Their
> products are not cheap, but they work. I have SurgeX protectors on all
> of my ham gear, computers, and audio/video gear.
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>

mcduffie

Re: [OT} Whole House Surge Protection

In reply to this post by Richard Fjeld

On Fri, 1 Feb 2013 11:59:00 -0600, Richard Fjeld wrote:

> I built a box with an AC relay that locks up through it's own contacts.

Did the same thing, except that the path also goes through a timer relay
that doesn't energize the AC path relay until power has been on for at
least 30 seconds without interruption.

Gary
--
http://ag0n.net
3055: http://ag0n.net/irlp/3055
NodeOp Help Page: http://ag0n.net/irlp
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Don Wilhelm-4

Re: [OT} Whole House Surge Protection

In reply to this post by Alan Bloom

Alan,

It should be a simple matter to open the strip and clip out the MOVs
(unless the construction is glued plastic).

73,
Don W3FPR

On 2/1/2013 4:43 PM, Alan Bloom wrote:

> The problem is it is getting hard to find decent-quality outlet strips
> that DON'T have surge protection built in. I am currently building up
> a second studio for KBBF-FM, a community bi-lingual station here in
> Santa Rosa. I wanted an outlet strip with some sockets spaced far
> enough apart to accommodate several wall transformers. I found the
> perfect device at Home Depot, but it has surge protection built in.
>
> Should I crack it open and remove the MOVs?
>
> Alan N1AL
>
>
> On 2/1/2013 12:02 PM, Jim Brown wrote:
>> On 2/1/2013 10:21 AM, Mark Bayern wrote:
>>> Someone brought out the fact that a power strip or some other device
>>> with a surge protector built in should cover everything on that
>>> particular leg. It's a parallel circuit.
>>
>> Nope. ANY shunt mode device (MOV) operates by conducting the spike to
>> the green wire or the neutral. The resulting current raises the voltage
>> on the green wire (which is connected to the chassis of the equipment
>> plugged into the "protected" outlet) to some very high value, depending
>> on the spike that sets it off. In the case of lightning, this can be
>> a lot.
>>
>> Now, consider equipment connected to two different power strips, with or
>> without an MOV, or to different locations, or to another ground. ALL of
>> those other points will be at a different potential as a result of
>> seeing the same spike, and again, in the case of lightning, that can be
>> a VERY large difference. it is the DIFFERENCE in potential from one
>> piece of gear to the other that fries those Ethernet ports, and it would
>> also fry signal interconnect circuitry for audio and video.
>>
>> THIS is why MOVs are a really bad idea on branch circuits. Those of us
>> working in pro audio have LOTS of interconnected equipment, often at
>> widely separated points, so we learned all of this the hard way nearly
>> 20 years ago. Our solution has been to use SERIES-MODE Surge Protectors,
>> and that has been quite effective. SurgeX and Brick Wall are the only
>> two companies I know of that have licensed the series mode patent. Their
>> products are not cheap, but they work. I have SurgeX protectors on all
>> of my ham gear, computers, and audio/video gear.
>>
>> 73, Jim K9YC
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Alan Bloom

Re: [OT} Whole House Surge Protection

Thanks Don. It's a metal case held together with screws, so there
should be no trouble opening it up to clip out the MOVs. The question
is whether I should do that. You pay extra for them, after all. :=)

Alan N1AL

On 2/1/2013 2:44 PM, Don Wilhelm wrote:

> Alan,
>
> It should be a simple matter to open the strip and clip out the MOVs
> (unless the construction is glued plastic).
>
> 73,
> Don W3FPR
>
> On 2/1/2013 4:43 PM, Alan Bloom wrote:
>> The problem is it is getting hard to find decent-quality outlet strips
>> that DON'T have surge protection built in. I am currently building up
>> a second studio for KBBF-FM, a community bi-lingual station here in
>> Santa Rosa. I wanted an outlet strip with some sockets spaced far
>> enough apart to accommodate several wall transformers. I found the
>> perfect device at Home Depot, but it has surge protection built in.
>>
>> Should I crack it open and remove the MOVs?
>>
>> Alan N1AL
>>
>>
>> On 2/1/2013 12:02 PM, Jim Brown wrote:
>>> On 2/1/2013 10:21 AM, Mark Bayern wrote:
>>>> Someone brought out the fact that a power strip or some other device
>>>> with a surge protector built in should cover everything on that
>>>> particular leg. It's a parallel circuit.
>>>
>>> Nope. ANY shunt mode device (MOV) operates by conducting the spike to
>>> the green wire or the neutral. The resulting current raises the voltage
>>> on the green wire (which is connected to the chassis of the equipment
>>> plugged into the "protected" outlet) to some very high value, depending
>>> on the spike that sets it off. In the case of lightning, this can be
>>> a lot.
>>>
>>> Now, consider equipment connected to two different power strips, with or
>>> without an MOV, or to different locations, or to another ground. ALL of
>>> those other points will be at a different potential as a result of
>>> seeing the same spike, and again, in the case of lightning, that can be
>>> a VERY large difference. it is the DIFFERENCE in potential from one
>>> piece of gear to the other that fries those Ethernet ports, and it would
>>> also fry signal interconnect circuitry for audio and video.
>>>
>>> THIS is why MOVs are a really bad idea on branch circuits. Those of us
>>> working in pro audio have LOTS of interconnected equipment, often at
>>> widely separated points, so we learned all of this the hard way nearly
>>> 20 years ago. Our solution has been to use SERIES-MODE Surge Protectors,
>>> and that has been quite effective. SurgeX and Brick Wall are the only
>>> two companies I know of that have licensed the series mode patent. Their
>>> products are not cheap, but they work. I have SurgeX protectors on all
>>> of my ham gear, computers, and audio/video gear.
>>>
>>> 73, Jim K9YC
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>

Alan Bloom

Re: [OT} Whole House Surge Protection

In reply to this post by Alan Bloom

Jim,

If I re-wire the outlet strip, would it make sense to leave an MOV
connected from hot to neutral as long as there are none connecting to
ground?

There could still be a high voltage spike on the ground due to the
impedance of the common path of ground and neutral between the breaker
box and earth, but it should be a lot less than all the wiring leading
up to the breaker box.

Alan

On 2/1/2013 1:43 PM, Alan Bloom wrote:

> The problem is it is getting hard to find decent-quality outlet strips
> that DON'T have surge protection built in. I am currently building up a
> second studio for KBBF-FM, a community bi-lingual station here in Santa
> Rosa. I wanted an outlet strip with some sockets spaced far enough
> apart to accommodate several wall transformers. I found the perfect
> device at Home Depot, but it has surge protection built in.
>
> Should I crack it open and remove the MOVs?
>
> Alan N1AL
>
>
> On 2/1/2013 12:02 PM, Jim Brown wrote:
>> On 2/1/2013 10:21 AM, Mark Bayern wrote:
>>> Someone brought out the fact that a power strip or some other device
>>> with a surge protector built in should cover everything on that
>>> particular leg. It's a parallel circuit.
>>
>> Nope. ANY shunt mode device (MOV) operates by conducting the spike to
>> the green wire or the neutral. The resulting current raises the voltage
>> on the green wire (which is connected to the chassis of the equipment
>> plugged into the "protected" outlet) to some very high value, depending
>> on the spike that sets it off. In the case of lightning, this can be a
>> lot.
>>
>> Now, consider equipment connected to two different power strips, with or
>> without an MOV, or to different locations, or to another ground. ALL of
>> those other points will be at a different potential as a result of
>> seeing the same spike, and again, in the case of lightning, that can be
>> a VERY large difference. it is the DIFFERENCE in potential from one
>> piece of gear to the other that fries those Ethernet ports, and it would
>> also fry signal interconnect circuitry for audio and video.
>>
>> THIS is why MOVs are a really bad idea on branch circuits. Those of us
>> working in pro audio have LOTS of interconnected equipment, often at
>> widely separated points, so we learned all of this the hard way nearly
>> 20 years ago. Our solution has been to use SERIES-MODE Surge Protectors,
>> and that has been quite effective. SurgeX and Brick Wall are the only
>> two companies I know of that have licensed the series mode patent. Their
>> products are not cheap, but they work. I have SurgeX protectors on all
>> of my ham gear, computers, and audio/video gear.
>>
>> 73, Jim K9YC
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>

Jim Brown-10

Re: [OT} Whole House Surge Protection

In reply to this post by Alan Bloom

On 2/1/2013 1:43 PM, Alan Bloom wrote:
> Should I crack it open and remove the MOVs?

If you put a SurgeX or Brick Wall box between them and the breaker
panel, they'll never see a surge, so no problem. Otherwise you should
remove the MOVs.

BTW -- many computers, computer accessories, copy machines, etc. come
loaded with MOVs too, and they can cause the same problem.

73, Jim K9YC

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Jim Brown-10

Re: [OT} Whole House Surge Protection

In reply to this post by Alan Bloom

On 2/1/2013 4:30 PM, Alan Bloom wrote:
> If I re-wire the outlet strip, would it make sense to leave an MOV
> connected from hot to neutral as long as there are none connecting to
> ground?

No, that can also do some mischief, although less.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

David Cutter

Re: [OT} Whole House Surge Protection

In reply to this post by mcduffie

These were very popular in Kenya where black-outs, drop-outs, brown-outs,
high surges
and spikes were common:
http://www.sollatek.com/product-list/voltshield/
http://www.sollatek.com/product-list/voltsafe/

Many fridges, freezers and all household equipment is saved using the
plug-in units. It was typical for the mains to read 400V (240V nom) when
the power returned after a drop out and the little units would just hold off
the load till those passed and a timer dropped back on.

David
G3UNA

----- Original Message -----
From: "AG0N-3055" <[hidden email]>
To: "elecraft" <[hidden email]>
Sent: Friday, February 01, 2013 10:29 PM
Subject: Re: [Elecraft] [OT} Whole House Surge Protection

> On Fri, 1 Feb 2013 11:59:00 -0600, Richard Fjeld wrote:
>
>> I built a box with an AC relay that locks up through it's own contacts.
>
> Did the same thing, except that the path also goes through a timer relay
> that doesn't energize the AC path relay until power has been on for at
> least 30 seconds without interruption.
>
> Gary
> --
> http://ag0n.net
> 3055: http://ag0n.net/irlp/3055