ESD Boot straps

[Pullnwire]

I have been doing alot of work in an electronics manufacturing facility latelely, and recently I was asked to wear ESD straps on my boots. I dont go near any of their equipment or their product but they insistr that I wear these straps. the fit on the heel of my boots, and veclro over the top with a long fabric strap that needs to get tucked into my sock. I think this will void the EH rating of my boots. The flooring in the facility is all ESD carpet that has a copper connection to building steel, thus groundig me wherever I go. Should I protest this request?

 

[kspifldorf]

I have a real problem with them, It just goes against everything I feel to be be safe. I know I'll probably get hammered on this but, troubleshooting live equiptment while having a ground rod " in your back pocket " is truly a delima.

 

[steved]

It's been a while since I worked in the electronics business and I may not remember this all correctly, but I believe ESD grounding devices such as wrist straps or heel straps usually have a large-value resistor in series to limit the current that can flow through them to a safe level. It's usually required that the individual wearing one of these devices test it every time it's worn. The tester should indicate if the resistance is either too low for safety or too high for ESD protection. Of course, the current that can flow depends on the voltage, and the manufacturers of the grounding devices recommend not using them if the wearer could be exposed to more than 250 Volts.

 

[ramsy]

Of course, the current that can flow depends on the voltage, and the manufacturers of the grounding devices recommend not using them if the wearer could be exposed to more than 250 Volts.

Carry one of these Mfg. recommendations and a Megger tester, and say you can't be grounded while testing.

 

[LarryFine]

It's been a while since I worked in the electronics business and I may not remember this all correctly, but I believe ESD grounding devices such as wrist straps or heel straps usually have a large-value resistor in series to limit the current that can flow through them to a safe level.

That is correct, and typically in the megohm range. One megohm would limit the current to 1 ma at 1 KV, so the danger is not great.

To static electricity, in the 10's of KV's, that high impedance is relatively low, and effectively drains the voltage to a low level.

Remember our discussions about EGC's being basically useless at typical secondary voltages, but rather effective to drain lightning?

 

[ramsy]

One megohm would limit the current to 1 ma at 1 KV, so the danger is not great.

Larry, unless you've proved this I don't believe DC devices are intended to stop alternating current. Imagine a DC circuit board bypassed to AC line voltage. Now imagine your brain on AC line voltage. Would you test this static device between an AC transformer and ground?

 

[76nemo]

Pullinwire,

I work in the industry and our company NEVER requires our contractors to wear lab coats or straps. The straps have a 1 megohm resistor in series.

You walk off the job if they persist. You are NOT in touch with their equipment. If they have onsite engineers, politely ask them to enter the debate. Don't bow down to what they ask for. I have worked a bench time off and on for many years. They have NO right to require this. You and your boss stand your ground and demand the companies engineers take part in this decision.

Why do you wear gloves and boots pullin'????? The dipsquirts in the front office don't have a clue. YOU STAND YOUR GROUND NOW!!!!!!!!!!

 

[electricalperson]

we work at lockeed martin and they make us wear those ESD jackets. i always tell them we cant wear them since they are conductive yet they dont care...

 

[76nemo]

we work at lockeed martin and they make us wear those ESD jackets. i always tell them we cant wear them since they are conductive yet they dont care...

They don't care????? Most of these engineers are DC app geeks. You BEST speak your piece. You aren't in touch with their equipment. Years ago, static protection was an important issue. MOS devices are not nearly as sensitive as they used to be. Your presense is of no concern. You are there working on their electrical system, not products. Most products in this age rarely suffer latent damage. Ask for the onsite engineers on this debate.

 

[electricalperson]

They don't care????? Most of these engineers are DC app geeks. You BEST speak your piece. You aren't in touch with their equipment. Years ago, static protection was an important issue. MOS devices are not nearly as sensitive as they used to be. Your presense is of no concern. You are there working on their electrical system, not products. Most products in this age rarely suffer latent damage. Ask for the onsite engineers on this debate.

in certain areas its required that everyone including the janitor, the plumber and whatever to wear those jackets. i never eve ncome close to the equipment so i dont think its needed. ever since lockheed martin bought them out the safety officers went crazy. we cant even do anything anymore. example: i like to use a blow torch to repair UF yet we cant even use a torch because we need to fill out hot work forms and have a firewatch stand over us making sure we dont light the dirt on fire.. it doesnt matter that much i dont mind doing what they say just sometimes its a pain

 

[76nemo]

Bottom line Chris, ISO, to my knowledge has no say to what outside contractors can perform. ISO only applies to what is performed in the facility itself day in and day out and THEIR employees. An outside contractor doesn't in anyway have to conform to the companies procedures that they hold alone. Although Lockhead may state this, as an outside contractor, you are free to go about what you need to do INSIDE the realm of THEIR safety regulations. I can't see wearing dissapative clothing as an electrical contractor as a safety stipulation.

 

[electricalperson]

Bottom line Chris, ISO, to my knowledge has no say to what outside contractors can perform. ISO only applies to what is performed in the facility itself day in and day out and THEIR employees. An outside contractor doesn't in anyway have to conform to the companies procedures that they hold alone. Although Lockhead may state this, as an outside contractor, you are free to go about what you need to do INSIDE the realm of THEIR safety regulations. I can't see wearing dissapative clothing as an electrical contractor as a safety stipulation.

i believe us following the safety rules is part of our contract and if we dont follow they will find another electrician. we have to follow them because we do TONS of work at that place. somebody is there just about every day.

 

[76nemo]

i believe us following the safety rules is part of our contract and if we dont follow they will find another electrician. we have to follow them because we do TONS of work at that place. somebody is there just about every day.

Chris, there isn't any "safety" rules behind the electronics industry standards of wearing dissipative clothing for electrical contractors.


Think about it. Why does the electronics industry ask that their employees wear dissipative clothing? They ask that of their employees to protect their products from static damage. You, or anyone else asked to come in and work on their electrical system should not be required to wear such gear. Why do we wear PPE Chris? As electrical workers, we have to isolate ourselves from ground, thee exact opposite as the employees working in the electronic fields worrying about static damage.

 

[ramsy]

Employees exposed to electrical hazards must never wear conductive shoes.

Special Purpose Shoes
Electrically conductive shoes provide protection against the buildup of static electricity. Employees working in explosive and hazardous locations such as explosives manufacturing facilities or grain elevators must wear conductive shoes to reduce the risk of static electricity buildup on the body that could produce a spark and cause an explosion or fire. Foot powder should not be used in conjunction with protective conductive footwear because it provides insulation, reducing the conductive ability of the shoes. Silk, wool and nylon socks can produce static electricity and should not be worn with conductive footwear. Conductive shoes must be removed when the task requiring their use is completed. Note: Employees exposed to electrical hazards must never wear conductive shoes.

Electrical hazard, safety-toe shoes are nonconductive and will prevent the wearers' feet from completing an electrical circuit to the ground. These shoes can protect against open circuits of up to 600 volts in dry conditions and should be used in conjunction with other insulating equipment ... Note: Nonconductive footwear must not be used in explosive or hazardous locations.

http://www.osha.gov/Publications/osha3151.html

 

[Fulthrotl]

Carry one of these Mfg. recommendations and a Megger tester, and say you can't be grounded while testing.

or even better yet, megger the person insisting you wear these to
demonstrate to their satisfaction why it's a bad idea.... start with
250 volts, to be kind....

randy

 

[iwire]

I would probably comply with the customers request.

I don't know about you guys but I know when I am exposed to electrical hazards. If we are following all the OSHA rules there are very few times we are exposed to electrical hazards anymore than a carpenter, roofer or assembly line worker.

When the time came that I was doing some work that would expose me to electrical hazards I could remove the strap from my foot as I was putting on my other required PPE.

Maybe its just me but regardless of my shoes rating I assume my shoes / sweat / dirt on my feet are conductive at all times.

 

[LarryFine]

Larry, unless you've proved this I don't believe DC devices are intended to stop alternating current. Imagine a DC circuit board bypassed to AC line voltage. Now imagine your brain on AC line voltage. Would you test this static device between an AC transformer and ground?

I don't understand your question, but resistors are not AC or DC devices, and they don't "stop" current, they limit it.

Direct grounding would discharge static, too; the resistor is inserted solely for the purpose of current limiting for safety.

Added: If you're asking if I would trust a 1meg resistor to limit shock, the answer is yes. I have an ESD wriststrap.

 

[zog]

Maybe its just me but regardless of my shoes rating I assume my shoes / sweat / dirt on my feet are conductive at all times.

And that is the way to think about it, wearing EH rated boots dosent change anything about the rules you follow or safety requirements that apply. All it takes is some other part of your body touching anything grounded and the boots ratings are meaningless.

 

[zog]

or even better yet, megger the person insisting you wear these to
demonstrate to their satisfaction why it's a bad idea.... start with
250 volts, to be kind....

randy

Actually getting meggered on 250V hurts more than 1000V (Limited source, less voltage=more current) we used to "experiment" with this theory on the submarine.

 

[George Stolz]

Maybe its just me but regardless of my shoes rating I assume my shoes / sweat / dirt on my feet are conductive at all times.

I agree, I feel the same way.