How To Properly Ground System

[Bob___]

I am considering setting up a system around the MPP Solar unit. How do you ground the system to protect against ground faults or accidental stray charge on an appliance chassis?
Electrical code says that Neutral (White Wire) and Earth ground (Green Wire )can only be bonded at the main breaker panel. How is the earth ground connection made when the transfer switch switches over to battery or Solar from utility?

 

[offgriddle]

Yes, combine earth ground and neutral at the main panel. Seperate earth ground and neutral at subpanels so if neutral should become disconnected, any devices will not seek a return path via ground, thus, energizing grounded cabinet's, housing's, conduits, chassis's etc and posing a shock hazard. You might want to consider a transfer switch kit ie: https://www.homedepot.com/p/Relianc...p-Manual-Transfer-Switch-Kit-310CRK/205793178

 

[Mac6792]

Yes, combine earth ground and neutral at the main panel. Seperate earth ground and neutral at subpanels so if neutral should become disconnected, any devices will not seek a return path via ground, thus, energizing grounded cabinet's, housing's, conduits, chassis's etc and posing a shock hazard. You might want to consider a transfer switch kit ie: https://www.homedepot.com/p/Relianc...p-Manual-Transfer-Switch-Kit-310CRK/205793178

My plan is to not be feeding my main panel at all, but I will be connected to AC for charging and low voltage cutover to ac power. I most likely will have a sub panel off the inverter for my loads. I'm still struggling to understand exactly how this should be grounded. I'd love to see a diagram.

 

[erik.calco]

My plan is to not be feeding my main panel at all, but I will be connected to AC for charging and low voltage cutover to ac power. I most likely will have a sub panel off the inverter for my loads. I'm still struggling to understand exactly how this should be grounded. I'd love to see a diagram.

Your earth ground would still be fed into the inverter in that topology. But I could find very little in the MPP Solar manuals on what happens inside the inverter. I read a manual of another inverter that talked extensibly about the ground and neutral, but I couldn't understand it. They talked about configuring based on your country, but didn't give examples for USA.

For our home circuits, one way or another they should be connected to earth ground, whether directly via the main panel or via the ground bar in the transfer switch, which will also get the earth ground as its AC input. A continuity test can verity.

I skipped over anything that said "how to ground in an RV" since I don't have an RV.

 

[Steve_S]

Maybe a bit of clarification is required here as it's a commo issue. AC & DC have different rules and differing terms which do not help the average person.
AC: Black & Red lines are HOT. White is Neutral (not ground). Exposed Copper / Green Wire is ground.
DC: Black is Negative. Red or other colour is Positive. There is no "ground" as such on the power side. DC Gear get's grounded in a fixed / shore based installation and that means grounding the Hardware. IN a vehicle the chassis is typically used as negative / ground but more often for safety reasons now Negative is run as an extra wire in vehicle circuits. Getting even more complex with electrified vehicles due to the computers.

AC must be grounded following Electrical Codes relative to your jurisdiction (the rules do vary a bit, make no assumptions). Grounding Plates, Rods are commonly used for such, in some cases it is allowed to use metal water pipes coming into a home (due to extensive use of PEX and others, most are eliminating this option). Main electrical panel is grounded and all plugs, switches, sub-panels etc are all bonded together with the bare copper / green wire and share the one common ground circuit for the structure. Think of it like a Daisy Chain, all linked together. Some codes allow for multiple grounding points (rods, plates etc) while others do not, your codes are your guide. (note, if you want insurance coverage, follow codes and get inspected as required)

Solar Panels (frames & rails) need to be grounded separately as their grounding is to protect from lightning etc. This is a separate grounding aside from the actual "electrical system" as such. There are likely various code requirements relative to your region, so again verify what these are and follow codes. It's not just for insurance purposes, these codes are designed to keep person & property safe and sound.

The "Bonding Thing" on inverters. Many are built in a manner that they can be used in a fixed installation such as a house or within a vehicle. If it is used in a house, the chassis' / housings of the equipment has to be bonded to ground using a bonding connector usually provided in the "kit". There may be an additional Lug for Earth Ground, depends on manufacturer. If in a vehicle then ground is to the chassis, which could also be negative and could cross so the equipment is separated (bonding wire not connected between the device chassis and power line). Refer to the Inverter Manuals & Docs in regards to this, the methods vary and there is no single simple answer. IF you do setup and things are running, always use an AC Plug Tester like this: https://www.amazon.com/Sperry-Instruments-GFI6302-Receptacle-Professional/dp/B000RUL2UU/ref=sr_1_6?keywords=Outlet+Tester,+Receptacle+Tester+for+GFCI&qid=1573991665&sr=8-6 to ensure your circuits are properly done, IF the bonding is not correct, it will generate a fault like an open circuit. Do that before connecting anything to your AC ! NB: That is a North American Model shown, similar are available for other electrical systems.

GFCI & Arc Fault are 2 different beasts and is understandable that there is some confusion there.

GFCI (Ground Fault Circuit Interrupter) breakers are for wet areas like kitchens and bathrooms. A “ground fault” occurs when the electric current leaves the intended route within the wiring and appliance, and the stray current may be traveling through your body. So GFCI is a shock protection device that trips within a fraction of a second when a fault is detected.

AFCI (Arc Fault Circuit Interrupter) breakers trip when any arcing, commonly called sparking, is detected in the circuit. Because arcing is the primary cause of electrical fires in a home, AFCI is a fire prevention device.

DFCI
A circuit breaker that provides both Ground Fault Circuit Interrupter (GFCI) and Combination Arc Fault Circuit Interrupter (CAFCI) is called a Dual Function Circuit Interrupter DFCI). The 2014 National Electrical Code (NEC) has mandated both AFCI and GFCI protection for many kitchen and laundry circuits, and the DFCI breaker provides both in one breaker. Some states, including Florida, have not adopted the new 2014 NEC yet, and we have only seen one of them so far. But DFCI breakers are on the horizon.

Both CAFCI and GFCI are safety devices. A CAFCI breaker guards against arcing or sparking caused by frayed wires and loose connection, which is a leading cause of house fires. GFCI breakers provide shock protection for the circuit by recognizing if an current has strayed outside its intended path and, if your body is where the current has leaked to, you could be shocked, burned, or even electrocuted. Although most CAFCI breakers provide GFCI-type shock protection, the current level to trip and response time does not meet the standards for a “Class A” GFCI, so they are not rated for GFCI-protection and the DFCI is a big improvement.
[/QUOTE

Hope this information helps.
Always refer to your Local Electrical Code Requirements.
Ensure you follow & comply with any requirements your insurance company may have, so you are covered. One mess up and they can deny claims.
Never be afraid to ask questions and double check what you are doing if you have any doubt whatsoever.

 

[offgriddle]

Bravo!;QUOTE="Steve_S, post: 14170, member: 1720"]
Maybe a bit of clarification is required here as it's a commo issue. AC & DC have different rules and differing terms which do not help the average person.
AC: Black & Red lines are HOT. White is Neutral (not ground). Exposed Copper / Green Wire is ground.
DC: Black is Negative. Red or other colour is Positive. There is no "ground" as such on the power side. DC Gear get's grounded in a fixed / shore based installation and that means grounding the Hardware. IN a vehicle the chassis is typically used as negative / ground but more often for safety reasons now Negative is run as an extra wire in vehicle circuits. Getting even more complex with electrified vehicles due to the computers.

AC must be grounded following Electrical Codes relative to your jurisdiction (the rules do vary a bit, make no assumptions). Grounding Plates, Rods are commonly used for such, in some cases it is allowed to use metal water pipes coming into a home (due to extensive use of PEX and others, most are eliminating this option). Main electrical panel is grounded and all plugs, switches, sub-panels etc are all bonded together with the bare copper / green wire and share the one common ground circuit for the structure. Think of it like a Daisy Chain, all linked together. Some codes allow for multiple grounding points (rods, plates etc) while others do not, your codes are your guide. (note, if you want insurance coverage, follow codes and get inspected as required)

Solar Panels (frames & rails) need to be grounded separately as their grounding is to protect from lightning etc. This is a separate grounding aside from the actual "electrical system" as such. There are likely various code requirements relative to your region, so again verify what these are and follow codes. It's not just for insurance purposes, these codes are designed to keep person & property safe and sound.

The "Bonding Thing" on inverters. Many are built in a manner that they can be used in a fixed installation such as a house or within a vehicle. If it is used in a house, the chassis' / housings of the equipment has to be bonded to ground using a bonding connector usually provided in the "kit". There may be an additional Lug for Earth Ground, depends on manufacturer. If in a vehicle then ground is to the chassis, which could also be negative and could cross so the equipment is separated (bonding wire not connected between the device chassis and power line). Refer to the Inverter Manuals & Docs in regards to this, the methods vary and there is no single simple answer. IF you do setup and things are running, always use an AC Plug Tester like this: https://www.amazon.com/Sperry-Instruments-GFI6302-Receptacle-Professional/dp/B000RUL2UU/ref=sr_1_6?keywords=Outlet+Tester,+Receptacle+Tester+for+GFCI&qid=1573991665&sr=8-6 to ensure your circuits are properly done, IF the bonding is not correct, it will generate a fault like an open circuit. Do that before connecting anything to your AC ! NB: That is a North American Model shown, similar are available for other electrical systems.

GFCI & Arc Fault are 2 different beasts and is understandable that there is some confusion there.
[/QUOTE]

 

[Steve_S]

EDIT - ADDITION :
I forgot to mention, Lightning Protection ! Something which I have noticed is rarely brought up. In fixed systems on the ground (cabin's, homes etc) lightning protection is important, one surge and all your goodies can go POOF with big clouds of Magic Smoke. Everything is an equal opportunity victim to lighting, so Never Underestimate what it can do to you & your gear.
A good reference article here: https://www.wholesalesolar.com/solar-information/grounding-lightning-protection

 

[erik.calco]

Maybe a bit of clarification is required here as it's a commo issue. AC & DC have different rules and differing terms which do not help the average person.
AC: Black & Red lines are HOT. White is Neutral (not ground). Exposed Copper / Green Wire is ground.
DC: Black is Negative. Red or other colour is Positive. There is no "ground" as such on the power side. DC Gear get's grounded in a fixed / shore based installation and that means grounding the Hardware. IN a vehicle the chassis is typically used as negative / ground but more often for safety reasons now Negative is run as an extra wire in vehicle circuits. Getting even more complex with electrified vehicles due to the computers.

AC must be grounded following Electrical Codes relative to your jurisdiction (the rules do vary a bit, make no assumptions). Grounding Plates, Rods are commonly used for such, in some cases it is allowed to use metal water pipes coming into a home (due to extensive use of PEX and others, most are eliminating this option). Main electrical panel is grounded and all plugs, switches, sub-panels etc are all bonded together with the bare copper / green wire and share the one common ground circuit for the structure. Think of it like a Daisy Chain, all linked together. Some codes allow for multiple grounding points (rods, plates etc) while others do not, your codes are your guide. (note, if you want insurance coverage, follow codes and get inspected as required)

Solar Panels (frames & rails) need to be grounded separately as their grounding is to protect from lightning etc. This is a separate grounding aside from the actual "electrical system" as such. There are likely various code requirements relative to your region, so again verify what these are and follow codes. It's not just for insurance purposes, these codes are designed to keep person & property safe and sound.

The "Bonding Thing" on inverters. Many are built in a manner that they can be used in a fixed installation such as a house or within a vehicle. If it is used in a house, the chassis' / housings of the equipment has to be bonded to ground using a bonding connector usually provided in the "kit". There may be an additional Lug for Earth Ground, depends on manufacturer. If in a vehicle then ground is to the chassis, which could also be negative and could cross so the equipment is separated (bonding wire not connected between the device chassis and power line). Refer to the Inverter Manuals & Docs in regards to this, the methods vary and there is no single simple answer. IF you do setup and things are running, always use an AC Plug Tester like this: https://www.amazon.com/Sperry-Instruments-GFI6302-Receptacle-Professional/dp/B000RUL2UU/ref=sr_1_6?keywords=Outlet+Tester,+Receptacle+Tester+for+GFCI&qid=1573991665&sr=8-6 to ensure your circuits are properly done, IF the bonding is not correct, it will generate a fault like an open circuit. Do that before connecting anything to your AC ! NB: That is a North American Model shown, similar are available for other electrical systems.

GFCI & Arc Fault are 2 different beasts and is understandable that there is some confusion there.

That is an excellent summary that belongs in the FAQ as a reference, for sure.

I suspect the OP, one of a large pool of Bobs, may never read this, unfortunately.

However, it sounded like he was just asking how the ground wire on the AC output would be grounded when it is isolated from the grid in terms of electrical generation source (PV/battery) using the MPP Solar. This is in part a physics question, because of the assumption that the ground has to follow live, which it does not. In the instructions for the install of the UL certified HD Reliance transfer switch I plan to use, you never disconnect the individual house circuit ground wires from the main panel's grounding bar. You are only re-routing the live that goes through the breaker. There is an additional ground however. And, when you wire the gen into the transfer panel, there is a ground for that. You will also run the ground from the main panel into the inverter when you connect the AC input. So the inverter really gets two connections to the main panel's earth ground (in your home.)

Where it becomes a black box for us, and the MPP Solar manual is no help, is what is happening inside the inverter. The manual for the inverter you recommended that one day went into a lot of detail. You helped to put some color on it. But, I have to admit, I cannot claim to understand what is happening inside these inverters.

The Samlex EVO manual, on the other hand, had a lot to say about it. But, it seemed to dance around the issue of code, which is the norm in these manuals that mention it. I find that very annoying because I know that in my locality, NEC 2011+ is the only thing that matters. Unlike building codes, where it defers to state and has exceptions, my locality has no exceptions. So, they could, at least, reference a particularly year in NEC and that would cover the majority of use cases for most USA buyers, and definitely for me. So, if they simply said "in the USA, in NEC 2013, you'll want to leave the default option," or you'll want to change it to blah, that would be all I needed. Instead, they leave it to me to figure out which of two inverter options I need to select.

Of course, inverters have to convert DC and AC, and, like you said, DC typically grounds to the chassis. So much of the jibberish was around grounding to the chassis, and whether or not ground and neutral should be shorted (AC), IIRC. I don't remember them coming out and saying it was a DC and AC combination issue. So, it sounded like there was an elephant in the room, but I wasn't 100% sure what that elephant's name was. That is why you feel more confused after reading it than you were before.

 

[Steve_S]

The Samlex EVO manual, on the other hand, had a lot to say about it. But, it seemed to dance around the issue of code, which is the norm in these manuals that mention it.

In regards to Samlex which likely applies to 90% of the more "serious" products out there, so document to the best of their abilities. Unfortunately, Electrical Codes & Requirements vary a lot between nations and systems. I the instance of Samlex, they are often used in marine or remote type conditions (that was their original target market space) so they lean that way in their documentation (which is extensive & plentiful). The Reality is that no single company can "Generically Document" compliance requirements because they would spend big money and publish doc's for different nations / continents. Some folks have a hard time understanding that NA is 240VAC Split Phase @ 60hz, while in Europe it can be 230VAC single Phase @ 50hz. and all sorts of variations are out there.... Hint: My green wire inside the inverter IS connected, no fault, no errors, solid grounding to 6", 20' deep Well Casing (not allowed in many regions btw, including my own technically). Panels are grounded to a Grounding Plate buried 3' deep. Lightning Protection is also installed (most important as I am on a Granite Ridge, 1200 feet above the valley connections).

 

[offgriddle]

This is a good explainer. Find a comfy chair in a quiet spot, put your feet up and focus upon and think about what you are reading. You may have a small dish of mixed nuts and perhaps a highly caffeinated bevvy whilst you ponder the below article. https://www.bluesea.com/support/articles/AC_Circuits/87/Differences_in_USA_and_European_AC_Panels

 

[erik.calco]

This is a good explainer. Find a comfy chair in a quiet spot, put your feet up and focus upon and think about what you are reading. You may have a small dish of mixed nuts and perhaps a highly caffeinated bevvy whilst you ponder the below article. https://www.bluesea.com/support/articles/AC_Circuits/87/Differences_in_USA_and_European_AC_Panels

LOL I don't want to know what EU is doing. I have to deal with them dominating US equities markets every day. Hot cocoa and chocolate chip cookies do not come to mind when I think about EU regulations.

I just want ONE SENTENCE in an inverter manual that has two options to choose which option to choose for NEC compliance in a home instead of pages dancing around it. That's it!

Let's be honest. This isn't about it being difficult for a Canadian company to know which option most NEC compliant American's will want. It's about plausible deniability... or, the letter of the law being more important than real practical safety.

 

[offgriddle]

I like your spirit, the more groups that mob up in to be enslaved by a pyramid scheme, the less sovereign individuality, choices and individual freedom and free agency there is. Creating a common core clueless proletariat to control, exploit & enslave by using the mass programming power of a government mono culture, "public", school monopoly, (such as what has happened to the heavily in debt and clueless about it, mass citizenry of the USSA over the past fifty years), is the preferred method of control over the majority by a lowest common denominator minority. ~ So what do people do who desire to not be assimilated by the collective? They grow their own, from generating electricial power, to food, to taking back the leading role in parenting and educating their own children. Bury the ruling politburo in their own huge governMental red tape and do not expect the public school monopoly raised mob to be able to make impartial decisions regarding free agency, instead, be the example of free agency for them and be patient. Communism is a non sustainable socioeconomic model and will eventually bankrupt itself in the USSA just like it did in the USSR and like it will do in the falsely named slave state of the "People's Republic" of China. ☮

 

[erik.calco]

I like your spirit, the more groups that mob up in to be enslaved by a pyramid scheme, the less sovereign individuality, choices and individual freedom and free agency there is. Creating a common core clueless proletariat to control, exploit & enslave by using the mass programming power of a government mono culture, "public", school monopoly, (such as what has happened to the heavily in debt and clueless about it, mass citizenry of the USSA over the past fifty years), is the preferred method of control over the majority by a lowest common denominator minority. ~ So what do people do who desire to not be assimilated by the collective? They grow their own, from generating electricial power, to food, to taking back the leading role in parenting and educating their own children. Bury the ruling politburo in their own huge governMental red tape and do not expect the public school monopoly raised mob to be able to make impartial decisions regarding free agency, instead, be the example of free agency for them and be patient. Communism is a non sustainable socioeconomic model and will eventually bankrupt itself in the USSA just like it did in the USSR and like it will do in the falsely named slave state of the "People's Republic" of China. ☮

A little off topic lol. But, yeah, that's the gist of it at the root.

The question is can DIY'er rise above the red tape and talk openly and objectively about safety in a public forum in simple terms without fear of reprisal?

 

[Steve_S]

@erik.calco what Canadian Company ? Samlex - Taiwan if your were thinking it was Canadian.

PS: Politics, Religion, Race and similar things are TOXIC in Forums and can quicky undermine & destroy a community such as this. This is an INTERNATIONAL forum, with people from all over the globe, with broad & wide experiences and from all walks of life. I believe, that many here are happy to be here because it is from such toxicity for the most part (sure we can outline how the media fumbled and fell from grace ;-) but with care.

Consider the following Short Read, still very much applies. IMO every politico, regardless of gender, race, creed or anything else should read & pass exams to see if they can grasp & understand.

37 Conversation Rules for Gentlemen from 1875

37 Conversation Rules for Gentlemen from 1875

Take heed of these 38 vintage conversation rules from 1875, and you'll get through every conversation with grace and poise.

www.artofmanliness.com

 

[Mac6792]

Steve_s. Fantastic overview! You're getting to root of my question. I will ground the panels To a combiner box with spd grounded to a ground rod. That should cover that. The mpp will be connected on the AC side (input) which will carry the house ground. My knowledge gap is the AC out from the mpp The AC out will be wired to separate isolated outlets that I will plug loads into. How should I ground those? In other words where is the ground coming from in the mpp inverter for ac out?

 

[erik.calco]

@erik.calco what Canadian Company ? Samlex - Taiwan if your were thinking it was Canadian.

Good point... I did assume Canadian. But, www.samlex.com appears to be EU. Can't find a reference to an international HQ, though. So, who knows.

Are you seriously taking offense at my frustration with inverter manuals? Honestly, I have a lot of respect for you because:
- You are experienced
- You are passionate
- You recommended a good inverter. I have not questioned the quality of Samlex, and you only claimed they were a quality inverter.
- You contribute, including helping us understand the complex world of electrical code.

I will continue to be frustrated with inverter manuals until I'm not. I am an insanely honest person, and I'm very honest when I say I am so tired of hearing "check your local codes". We are DIY's, not electricians. Those codes were not written for us.

On top of that, I've found them to be scams. The NFPA will let you graciously read the code on their site using a really crappy interface. But, it costs $65 to get the PDF. WTF?!? (I remember that as being closer to $145 last year... dunno why).

No one should have to pay $65-145 to get a PDF of code that their law requires them to comply with.



Steve, you are a really cool person. Don't throw out the incredible high level of respect I have for you defending the indefensible.

It looks like "digital access" may not even include the PDF, thus the $65 price...


If I select 2011, I get this option:


There is a distinction. But I can't figure out how to buy the PDF anymore. Looks like they buried it because they don't want the PDF circulating:



Can you understand why many of us cringe when someone says "check your local codes"? It's not because we don't want to be safe.

 

[Steve_S]

@erik I'm not taking anything in anyways.... no offense at all, I got very frustrated reading too much techno blabble too ! I do not have a magic decoder ring, although wish I did and could sell it, would be the richest person ever,

@Mac6792
I do not know your product so a "generic" answer.

The Inverter has AC Ground connected to it via it's AC Line ground wire connection to your panel, assuming the AC panel is properly grounded.
AC coming in from Grid is already grounded if it is coming from an installed panel but the ground wire has t be connected from that line to the inverter.
AC coming from a Generator is a bit weird. This get's many ! Some Gennies can be physically grounded (chassis) externally, some require it. Other's can operate safely without a chassis ground... A 'fairly typical' setup is to use an L5:30 plug (120v/30a max) to power the charger side of inverter combo. The better way to make that connection, is to hardware from inverter/charger to a small AC mini-panel which has a breaker to handle incoming max. like a single pole 40A AC breaker This little box is also connected & ground bonded to your AC side through the inverter and the L5 line from that box carries through to the generator. There could be an Auto-Start switch in between there as well, similar grounding via the wiring.

If you peak at my signature, there is a link to my setup which has pics & diagrams of how I am setup, that may help a bit. EDIT: Note that I cleared my land (was never farmed or touched), & built my home, out buildings and setup myself from the ground up. No contractors but for the concrete pour and the final finishing which allowed me to plan into the construction my needs and particular desires. There is some advantages to that. One important point in 'general' on Inverters/chargers... some (not all) have internal breakers ( push button or slide), they are very basic, work but I personally learned to never rely on them to function properly. Therefore I use an external breaker for AC-IN from Genny and another external breaker between my Inverter & primary panel which is capable of handling the surge rating of my inverter. These do have to match max input for the AC IN and the max output of teh AC OUT from the inverter to load side.

Hope it helps.

 

[erik.calco]

I do not have a magic decoder ring, although wish I did and could sell it, would be the richest person ever,
@Mac6792

You could create this... a site that let's you input what you are building and parameters, and pulls from a database all you need to know. For example,

I want to build a Pavilion. It will take me days to pull together all the relevant codes and turn them into a BOM. Why can't I just select Pavilion, put in 3 dimensions for size, and location, and get all the codes that will apply, or perhaps as a few more questions like "is it 10+ feet from the property line" and "please select type of roof". I know that only state matters for building codes because I already checked my local.

Sites like this are beginning to appear. But, that's what DIY'ers need.

 

[Steve_S]

You could create this... a site that let's you input what you are building and parameters, and pulls from a database all you need to know. For example,

I want to build a Pavilion. It will take me days to pull together all the relevant codes and turn them into a BOM. Why can't I just select Pavilion, put in 3 dimensions for size, and location, and get all the codes that will apply, or perhaps as a few more questions like "is it 10+ feet from the property line" and "please select type of roof".

Sites like this are beginning to appear. But, that's what DIY'ers need.

Well, you can also think that doc's and such are so sad in many cases is to more or less to push folks to use installers / electricians etc... Electrical Authorities prefer it that way too and some insurance companies insist on it, regardless if on / off grid. The pro's handle the Brain Pain and Tylenol infusion with Caffeine while Joe & Jane Customer foot the bill and not have the pain of the rest. IMO the Bill is pain too but some do not see not that way.

 

[erik.calco]

Well, you can also think that doc's and such are so sad in many cases is to more or less to push folks to use installers / electricians etc... Electrical Authorities prefer it that way too and some insurance companies insist on it, regardless if on / off grid. The pro's handle the Brain Pain and Tylenol infusion with Caffeine while Joe & Jane Customer foot the bill and not have the pain of the rest. IMO the Bill is pain too but some do not see not that way.

We all know and understand the status quo. DIY'ers are those who don't accept the status quo. We are willing to purchase materials and built it ourselves. We would love to discuss how to do it safely. The primary need for Tylenol is keeping the status quo from punishing us for it.