Grounding when building a Custom Rig

[snowcrashed]

I've seen many different types of custom rig containers.  Some very well thought out and constructed with care and others nothing more than a milk crate.  When building a custom rig, how can I ensure that key components are grounded properly?  It is my understand that in a standard computer case the metal screws/risers that connect the motherboard to the case are grounding the motherboard.  How is the motherboard grounded when making a custom case, where lets say the base the motherboard rests on is wood or plastic?

[Jama]

I've seen many different types of custom rig containers.  Some very well thought out and constructed with care and others nothing more than a milk crate.  When building a custom rig, how can I ensure that key components are grounded properly?  It is my understand that in a standard computer case the metal screws/risers that connect the motherboard to the case are grounding the motherboard.  How is the motherboard grounded when making a custom case, where lets say the base the motherboard rests on is wood or plastic?

It is grounded through the 24 pins and 4/8pin power connectors from the power supply.
If you look at the wires you will see several black wires, each is a ground wire.

You should not need any additional grounding.
I have 3 motherboards floating and have no issues.

[cp1]

The screws and risers aren't electrically connected.

[snowcrashed]

I see, I received some bad information then.  I thought that didn't sound right, but then my source seemed to know what they were talking about.

[cp1]

You don't want multiple grounding points anyway, you want one central ground as best as you can.

[Trongersoll]

The screws and risers aren't electrically connected.

Actually, if you look closely at your motherboard you will see where the grounding circuit in the MB does indeed connect to the case risers and screws.

As for the open computers as has been said, they are grounded to PS. Paper is a terrible conductor, as is wood so there is no issue. Plastic on the other hand can be a good source of static electricity.  

[cp1]

The screws and risers aren't electrically connected.

Actually, if you look closely at your motherboard you will see where the grounding circuit in the MB does indeed connect to the case risers and screws.

As for the open computers as has been said, they are grounded to PS. Paper is a terrible conductor, as is wood so there is no issue. Plastic on the other hand can be a good source of static electricity.  

Interesting -- it always looks to me like just an insulated pad, but I may not have looked at other layers closely.

[snowcrashed]

The screws and risers aren't electrically connected.

Actually, if you look closely at your motherboard you will see where the grounding circuit in the MB does indeed connect to the case risers and screws.

As for the open computers as has been said, they are grounded to PS. Paper is a terrible conductor, as is wood so there is no issue. Plastic on the other hand can be a good source of static electricity.  

So if I'm understanding you correctly, The case risers/screws are a part of the grounding but if the motherboard is resting on wood there's no problem since the PSU provides the grounding and wood is a poor conductor.  Is that accurate?

[Trongersoll]

yes, more or less. I'm sure knit pickers could expand the arguement for using a case.

[ISAWHIM]

There are two types of grounds...
- True-Ground (Normal ground, all metal components touching.)
- Isolated-Ground (What is commonly called the "-12v, -5v, -3.3v rails" or "common".)

Not all PSU's are created equal. Some use the "Ground" as the "Common", without isolation. (Ground-loop isolators.)

It does not matter how many "points" you have, as long as you have ONE point that is low-resistance. (Copper wire) Adding more points will help to ensure that you are adequately shielding RF noise, from both emanating and absorbing it. There is no "issue" of "ground-looping", through the high-resistance "STEEL-ALLOY" cases. (Unless you have faulty or ill-speced equipment and wires.) You do guarantee that the potential damage from shock, or accidental "short-circuiting" is limited, with correct grounding. Without it, you just open your system up for potential harm and damage.

Can you live without ground connections... Yes.
Will you damage anything without them... Not just by the absence of them.
What will happen without them... Slightly more "noise" in your AM/FM radio, and your CFL lights may "disrupt" some high-speed data-lines, but those will auto-adjust. Plus static-sounds and pops or "whines/humming" in your sound-card/speakers.

What is proper and safe, is to encase the entire unit with the ground, with multiple connections to that ground.

Ground points on a computer...
- The PSU case/screws
- The tower case/screws
- The mobo risers/screws
- The card mount-plates/screws
- The "common" wires on all DC plugs
- The hard-drive case/screws

Electricity takes the "path of least resistance", thus, most "ground/common" power will ALWAYS flow through the low-resistance copper wire. However, ESD and RF don't care about resistance, and often travel faster across high-resistance surfaces. (Plastic/skin). That is the "purpose" of ground-shielding and ground-isolation. (Ground-isolation is just higher points of added resistance, ti "ensure" that the lower-resistance is traveling where it is more desired. In the event of over-loading, additional GROUND -volts, will be allowed through any isolated connection, which is desired, to reduce damage/fire/heat/wires.)

Low-resistance - High-voltage things...
- Spark-plug wires (98% resistance, glass-insulated.)
- Capacitors (The inner plates separated by insulated material, glass, plastic, air, oil.)
- Van-de-Graaff generators (Rubber/leather is the "source" and the highest resistance.)
- Wimshurst-influence machines (Ebony or plastic or glass is the "source" and highest resistance.)
- Trees, you, diamonds or anything organic with a carbon-base... but not carbon itself, which is low-resistance, with the ONE exception for lattice-diamond-structures. (Carbon fibers even have "apparent" negative resistance.)
http://www.wings.buffalo.edu/academic/department/eng/mae/cmrl/Apparent%20negative%20electrical%20resistance%20in%20carbon%20fiber%20composites.pdf

[systic]

good info

[pekv2]

Also, make sure yourself is grounded some how to the mobo plate when working with the components. What I do, is have a single mobo stand off connected to the mobo plate, that I connect my static bracelet clamp to, prior to working with any hardware components.

[snowcrashed]

Also, make sure yourself is grounded some how to the mobo plate when working with the components. What I do, is have a single mobo stand off connected to the mobo plate, that I connect my static bracelet clamp to, prior to working with any hardware components.

Could you elaborate?  I don't quite understand what you're saying :x

[pekv2]

Also, make sure yourself is grounded some how to the mobo plate when working with the components. What I do, is have a single mobo stand off connected to the mobo plate, that I connect my static bracelet clamp to, prior to working with any hardware components.

Could you elaborate?  I don't quite understand what you're saying :x

http://en.wikipedia.org/wiki/Antistatic_wrist_strap

It's a method of protection, from accidentally transferring static electricity from your body to hardware components and from frying them.

Also, a motherboard plate/tray.
https://encrypted.google.com/search?q=motherboard+plate&hl=en&gbv=1&source=lnms&tbm=isch&sa=X&ei=pZOnUaqrLYbKObS7gfgC&ved=0CAcQ_AUoAQ

Motherboard stand offs.
https://encrypted.google.com/search?q=motherboard+stand+offs&btnG=Search&hl=en&gbv=1&tbm=isch

[pekv2]

A better explanation.

https://dl.dropboxusercontent.com/s/257ugqxb0yn9xc1/2013-05-30_13-07-18_547.jpg

[razorfishsl]

Why would you want too?
The main reason for grounding is electrical safety, I.E to provide an integrated environment, where electrical goods can operate within a safety cage.

Then the US goes and does something stupid like have 2 pin plugs!!!! (which are reversible....)... hay let's not even put the Live feed through a fuse safely..... (if the fuse is on the neutral line and it blows... then the equipment is STILL tied LIVE!!!)

First, decide WHY you want to do it... then get back to us.

[snootch]

Why would you want too?
The main reason for grounding is electrical safety, I.E to provide an integrated environment, where electrical goods can operate within a safety cage.

Then the US goes and does something stupid like have 2 pin plugs!!!! (which are reversible....)... hay let's not even put the Live feed through a fuse safely..... (if the fuse is on the neutral line and it blows... then the equipment is STILL tied LIVE!!!)

First, decide WHY you want to do it... then get back to us.

Huh? US uses the 5-15 (3 pin with ground) socket mostly... The 1-15 (two pin) are only used for double-insulated small appliances, and the socket hasn't been approved for new construction since 1965. Reversible does not make a damn bit of difference, it is AC power, and the breaker is on the live side. The 5-15 is no different than the BS 1363 (British plug) except the 5-15 doesn't have that stupid fuse in it that's a pain in the ass to replace. The reason the fuses are in the BS plugs is because British standards allow large circuits (up to 36A) and the fuse will blow if the equipment shorts. In the US, they use smaller circuits tied to breakers (1 circuit per room or area) where if a device shorts the circuit, the breaker trips. IMHO the US system is better... two weeks ago, I had a power strip go bad, and had to walk all over the house switching off/on outlets and resetting the breaker to troubleshoot where the short was occuring since almost ALL the outlets in the flat are on the same circuit.

[snowcrashed]

Also, make sure yourself is grounded some how to the mobo plate when working with the components. What I do, is have a single mobo stand off connected to the mobo plate, that I connect my static bracelet clamp to, prior to working with any hardware components.

Could you elaborate?  I don't quite understand what you're saying :x

http://en.wikipedia.org/wiki/Antistatic_wrist_strap

It's a method of protection, from accidentally transferring static electricity from your body to hardware components and from frying them.

Also, a motherboard plate/tray.
https://encrypted.google.com/search?q=motherboard+plate&hl=en&gbv=1&source=lnms&tbm=isch&sa=X&ei=pZOnUaqrLYbKObS7gfgC&ved=0CAcQ_AUoAQ

Motherboard stand offs.
https://encrypted.google.com/search?q=motherboard+stand+offs&btnG=Search&hl=en&gbv=1&tbm=isch

Ah that's what I thought you were getting at, I just didn't quite understand the wording.  Thanks for the suggestion.

[ssateneth]

For what it's worth, I've gotten up from my chair numerous times and went to physically touch my running mining equipment. I've shocked it maybe 3 or 4 times now with static electricity, and it just continued to run like a boss. Didn't restart, freeze, crash, shut down, anything. The charge from my finger likely jumped to a ground and it dissipated through that. This is why it's important that your electrical socket is grounded

[Trongersoll]

For what it's worth, I've gotten up from my chair numerous times and went to physically touch my running mining equipment. I've shocked it maybe 3 or 4 times now with static electricity, and it just continued to run like a boss. Didn't restart, freeze, crash, shut down, anything. The charge from my finger likely jumped to a ground and it dissipated through that. This is why it's important that your electrical socket is grounded

ElectroStatic Discharge (ESD) is more of an issue when the equipment is off and you are working on it. I've seen microscopic pictures of ESD damaged Integrated Circuits. It is a real problem and not visible to the human eye. wear your static strap while working on your equipment. be grounded. keep plastic and nylon away.