Grounding.

[Wabbit]

So this happened. A lightning strike somewhere close sent a surge over a new Sony 75" TV through the network LAN or AC cable (with no ground) and through the HDMI cable where it killed the single HDMI port on a Denon X3600H. The TV wasn't on a surge protector but the receiver was on a Furman 215A surge/conditioner that had tripped an over voltage light. The TV had to be unplugged for a minute but had no issues. The HDMI board was replaced on the AVR.

So Denon says to check the grounding of the device connected to the AVR. How? The factory plug of the TV has no ground pin. They then say power surge protectors do not help. Really? I pressed them to clarify and only said...

I can use the signal ground on the back of the AVR to go to a the center lug of a grounded AC outlet.

Anyone using the signal ground screw on your AVRs? I did learn that a lightning strike can literally effect an entire block. My neighbors lost more then I did. Has me considering a "whole house" surge protector, but I don't know how Denon would comment on that.

 

[TLS Guy]

So this happened. A lightning strike somewhere close sent a surge over a new Sony 75" TV through the network LAN or AC cable (with no ground) and through the HDMI cable where it killed the single HDMI port on a Denon X3600H. The TV wasn't on a surge protector but the receiver was on a Furman 215A surge/conditioner that had tripped an over voltage light. The TV had to be unplugged for a minute but had no issues. The HDMI board was replaced on the AVR.

So Denon says to check the grounding of the device connected to the AVR. How? The factory plug of the TV has no ground pin. They then say power surge protectors do not help. Really? I pressed them to clarify and only said...

I can use the signal ground on the back of the AVR to go to a the center lug of a grounded AC outlet.

Anyone using the signal ground screw on your AVRs? I did learn that a lightning strike can literally effect an entire block. My neighbors lost more then I did. Has me considering a "whole house" surge protector, but I don't know how Denon would comment on that.

This is not a simple answer and difficult. Nothing is fool proof. You do need to make cable satellite and ethernet connections are grounded to code. Unfortunately they often are not as the technicians are so often poorly trained Wally Brains.

Now whole house surge protection at the panel should always be in place if you are a home owner. This will not only protect your AV gear but expensive boards in other costly appliances like fridges and furnaces etc.

Next driving your AV equipment and computers from UPS units (uninterruptible power supplies) is a very good idea. This way when the AC gets dodgy in storms your equipment promptly connects to battery and is isolated from the grid.

 

[Wabbit]

The part that tripped me up was the lack of a ground on the TV, and in all honesty the signal ground terminal on the back of the AVR that I never hear anyone talk about. Since, I have placed good surge protectors on every connected device.

 

[Wabbit]

Upon further reading, it seems the signal ground is used for a phono player, and I would think the AVR is properly grounded through it's own 3 prong AC cord. Kinda thinking Denon support is smoking something having wrote this and explaining I only have the TV connected to the AVR. It's an AVR, not a rocket.:

No ground pin on the AC cord but he can ground the AVR-X3600H using the signal ground screw on the rear panel and using a wire go to a "water pipe" type ground or the ground lug or middle plate screw of an AC outlet.

 

[TLS Guy]

The part that tripped me up was the lack of a ground on the TV, and in all honesty the signal ground terminal on the back of the AVR that I never hear anyone talk about. Since, I have placed good surge protectors on every connected device.

Those surge protectors offer minimal protection. They are not in the right place. In addition you really need a device that will give you instant disconnect from the AC supply.

If you have a lot of very expensive equipment like I do, then ultimate protection includes a whole house generator, so the house can be disconnected from the grid in times of violent electrical storms. But as I said there is no absolutely full proof protection. Your risk very much depends on your location. For instance in my last rural location power surges were very common and I employed the generator often in violent summer storms. Now in the Twin Cities metro, that are less common, but still happen and so the generator has been employed. The US mid west is legendary for its violent electrical storms. So location is a big determinant of how much protection is required, and also how much you have to loose.

 

[highfigh]

Lightning is a wild card and when it strikes, all bets are off because the amount of energy is immense. Not only can it cause damage through a direct strike, it can cause damage via induced voltage in power lines, house wiring and the devices themselves, just by striking nearby. The TV has a ground connection to the AVR through the HDMI cable and technically, through the neutral, which is then grounded at the breaker panel if your location is in the US or it has a similar electrical system to what is used here.

 

[Speedskater]

It's common for modern electronic components to NOT have a Safety Ground connection. Either it's of a double insulation construction (square within a square safety symbol) or it has a double insulated external power supply.
Surge protection should take place at the AC service entrance of the building. This also includes telephone, cable/satellite TV and internet systems.

 

[viorelc]

I moved to South Florida 5 years ago, and my first thing was to protect my audio systems (mini studio mixing rack), entertainment audio-video units and computers (including the internal network).
All these are plugged in Furman surge protectors (Mx8 I believe) and all my network devices are my own, rated for surge protection (24kV I think). The place I live in is said to be the Lightning Capital of the US, and without claiming that to be true I can tell that we have a lot of electrical storms, on top of the full storms specific to Florida. Never had a device damaged, but had many times where the devices have been turned off by the surge protector during storms.

That said, I agree that surge protection is complicated, and especially in relation with lightning. What I did with my setup was to help my equipment’s chances during such incidents, and so far I’ve been able to keep them alive. Luck is one part, but preparation helps too, in my opinion.


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[Paul DS]

You really should have all your electronic equipment plugged into a combination UPS/Power Surge protector.

 

[highfigh]

Surge protection should take place at the AC service entrance of the building. This also includes telephone, cable/satellite TV and internet systems.

Protection from external surges yes, but devices inside of buildings can cause surges, too- these are minimized or stopped by protectors local to the devices that need it (rack, AV cabinet, TV, computers, etc).

 

[ellisr63]

I have 2 UPSs, a Furman power unit, and a APC power center, in addition to a whole house surge protector, and a whole house power regulator.

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[highfigh]

I moved to South Florida 5 years ago, and my first thing was to protect my audio systems (mini studio mixing rack), entertainment audio-video units and computers (including the internal network).
All these are plugged in Furman surge protectors (Mx8 I believe) and all my network devices are my own, rated for surge protection (24kV I think). The place I live in is said to be the Lightning Capital of the US, and without claiming that to be true I can tell that we have a lot of electrical storms, on top of the full storms specific to Florida. Never had a device damaged, but had many times where the devices have been turned off by the surge protector during storms.

That said, I agree that surge protection is complicated, and especially in relation with lightning. What I did with my setup was to help my equipment’s chances during such incidents, and so far I’ve been able to keep them alive. Luck is one part, but preparation helps too, in my opinion.


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You are in the lightning capital- I have spoken with tech support from Denon/Marantz and Yamaha- both have stated that they see more damaged equipment from Florida than any other place. Electronic Express, who is one of the service centers authorized by most brands of equipment told me the same.

Best practice- stop it at the service entrance if it can come from outside and use local protection to stop surges from things in the building, like motors & switches.

 

[Speedskater]

Protection from external surges yes, but devices inside of buildings can cause surges, too- these are minimized or stopped by protectors local to the devices that need it (rack, AV cabinet, TV, computers, etc).

Some experts make a strong case that just the opposite is true.

 

[Mark E. Long]

I use two monster power surge protectors in my system they have saved equipment from close by strikes . But a couple years ago a direct hit took one of them out and caused massive damage to my Yamaha AVR burnt out all the hdmi’s and took out the main processing board after looking at new units I decided to fix it mainly becouse I would not really gain much in the way of improvement except for Atmos I already run 11.2 so Iam good with that . The power centers did save my carver amps and my Art Eq’s but it did wipe out the Comcast dvr box which was junk anyhow lol . Yamaha’s conclusion was the hit came in threw the cable box wiping the avr out nothing was powered on at the time except the monster cable protection. I use the through function on the aver for tv sound with no system power . Finale cost new power center and a rebuild of the Yamaha . But Iam looking to put two dedicated circuits in just for the gear so it might be better protected . If the whole system would have been in use I shudder to think the damage that would have been done .

 

[TLS Guy]

Some experts make a strong case that just the opposite is true.

The only device likely to cause a surge inside most homes is the AC air compressor motor, and then only if it has failing starting and or running caps. These should be professionally checked every year before the start of each cooling season. Failing to check these caps causes more failure of electronic equipment than generally realized. If you note any change in your lighting as the AC starts, get these caps checked right away.

 

[TLS Guy]

I use two monster power surge protectors in my system they have saved equipment from close by strikes . But a couple years ago a direct hit took one of them out and caused massive damage to my Yamaha AVR burnt out all the hdmi’s and took out the main processing board after looking at new units I decided to fix it mainly becouse I would not really gain much in the way of improvement except for Atmos I already run 11.2 so Iam good with that . The power centers did save my carver amps and my Art Eq’s but it did wipe out the Comcast dvr box which was junk anyhow lol . Yamaha’s conclusion was the hit came in threw the cable box wiping the avr out nothing was powered on at the time except the monster cable protection. I use the through function on the aver for tv sound with no system power . Finale cost new power center and a rebuild of the Yamaha . But Iam looking to put two dedicated circuits in just for the gear so it might be better protected . If the whole system would have been in use I shudder to think the damage that would have been done .

Cable systems can be a big source of problems. One reason is the incompetence of cable and satellite company installers. I always beef up the grounding at entry.

The cable system is bonded to the studio rack system at entry to the studio. The racks are all firmly bonded together, and the racks bonded back to the panel with a huge copper grounding cable.

Even so, nothing is fool proof. However my experience is that most installations leave gates and doors wide open for lightening to steel your systems. I believe that most damage people experience could have been prevented. In this arena do not leave it to the average, builders, journey men and installers. Take charge yourself. Buying a bunch or surge protectors at Target or Home Depot does not cut it.

 

[Mark E. Long]

I agree after this I put in my own ground stake outside and ran separate ground wires to anything that would except it here in my area eastern Ohio for some reason we get a lot of fluctuations in our power everybody has had problems with it . I’ll take no chances again was an expensive repair job that time .

 

[Wabbit]

So my takeaway.... cover your a$$ at every possible point. More stuff to buy. Glad my internet is fiber.

 

[lovinthehd]

So my takeaway.... cover your a$$ at every possible point. More stuff to buy. Glad my internet is fiber.

Wow, you have an actual fiber that comes into your house? While we have fiber into town, the connections to the house are standard coax copper type and still require grounding....

 

[Wabbit]

Yep, actual fiber. It's a thin little cable too that they bury in your lawn leading to the house. Plus, I'm already being irradiated by 5G.

The actual repair technician of my AVR said he has everything on one extension cord that he unplugs when a storm comes. Oh' the thoughts that ran through me head. The actual power company said they can test if there is an adequate grounding rod for a fee. Google that stuff and there's a few endless rabbit holes about using dedicated rods.