OK, here's the deal with module bonding: No it would not be acceptable to use star washers as module bonding, NEC articles 110.3 and 690.4 both require equipment to be tested and listed for the application.
To that end, the WEEB clip itself has use limitations which should be adhered to:
The first listing the WEEB clips received was from ETL, or Intertek labs, testing was done to U.L. 467 for bonding, which is still a questionable decision because 467 does not provide any weather element to the testing. According to Intertek Engineering department the only modules that were tested under this application were Sharp modules, the racking that was tested only included Unirac, Direct Solar, and Pro Solar systems, so you can use the WEEBS to bond Sharp modules to any of those three mounting systems under the ETL listing.
The second "listing" they received was also via Intertek labs, Enphase had the clips tested to U.L. 1703 to allow the D/C GEC to provide equipment grounding for the rack, via the micro inverter.Contrary to popular belief the #8 D/C GEC still needs to be run to each inverter and the clip bonds the rack..
The last listing they received is not actulally a "listing", it is a U. L. "component recognition mark", what that means is that some modules were tested using the WEEBS, this component recognition mark only allows the WEEBS to be used on modules that were tested and listed by U.L.(and no other lab), and, it needs to be in the module manufacturer's installtion instructions to allow the WEEBS for module bonding (because U.L. vetts those instructions as well, so if it is in there U.L. tested them with the clips.)
Lastly, you could not use any clips for bonding any modules if there is going to be a need to use the module as an access panel to service micro inverters or j boxes because NEC section 690.48 "continuity of equipment grounding systems" requires jumpers to be installed on these modules.
So the bottom line is, all module bonding, including the use of the WEEB,S must be in accordance with the module manufacturer's installation instructions, and the listing/s indicated, and you can not use any bonding clips (including WEEBS) on a module that needs to be removed to access a j box or inverter.
Todd, the anodized surface of aluminum has a very high resistance. That is why it must be pierced by some device or removed to make a good electrical contact with the grounding device. Emmett, it depends on how you define "would it work." It would not be NEC compliant and it would not last. It would probably have a low resistance when first installed and provide a good ground, but remember that these need to last for 30+ years. That star washer might make a great ground for a couple of months but then corrosion of the washer and the surfaces on either side would add resistance until it was no longer providing a good ground. Then a few years down the line when there is a ground fault in the array and no ground connection someone goes out there and touches the module and is hurt or killed. Proper grounding will prevent this. Stick with listed grounding devices that will make long lasting ground connections and provide safety for the life of the PV system.
I measured the resistance of an clear anodized mounting rail and there was no resistance to speak on, So I don't know where you are getting your information from but from my personal testing of the equipment I have in place it isn't an issue.
I wouldn't have any objections to using stainless steel internal+external lock washers to provide a ground connection between the equipment. The only reason for a grounding the metal frame is for potential lightning strikes, when you compare a webb clip to a star washer, the star washer clearly has the better teeth and greater contact area for surface penetration.
Ensuring the reliability of solar panel installations is paramount for their long-term performance. While traditional star-washers have been commonly utilized for electrical bonding and grounding, their inherent risks can compromise the integrity of the system over time.
One significant concern is water leakage, which arises when conventional washers degrade, failing to maintain a secure seal around the mounting brackets. This vulnerability exposes the panels to water ingress, posing a threat to the wiring and circuitry within.
Moreover, the use of traditional star-washers can contribute to structural issues. As these components corrode, they jeopardize the stability of the panel frame, potentially leading to instability and vibrations during windy conditions. Such vibrations exert undue stress on the frame, increasing the likelihood of cracks and structural damage.
Additionally, the efficiency of solar panels may be adversely affected by faulty star-washers. Corrosion-induced loosening can result in panel movement, thereby disrupting the optimal orientation for sunlight capture. This deviation reduces the amount of sunlight reaching the cells, consequently diminishing overall energy output.
To mitigate these risks, the adoption of SURE-BOND Environmentally Sealed Star-Washers is recommended. Specifically engineered for solar panel applications, these washers ensure a robust and watertight seal around the mounting brackets, safeguarding against water intrusion and structural compromise. By choosing SURE-BOND, installers can minimize the need for frequent washer inspections and replacements, enhancing the reliability and longevity of the solar array.
Comments
The surface of Anodized aluminium doesn't have much resistance, so a star washer would offer the same effect.
However, the 10K dollar question is will it pass a detailed inspection?
Best to ask L&I this one.
OK, here's the deal with module bonding: No it would not be acceptable to use star washers as module bonding, NEC articles 110.3 and 690.4 both require equipment to be tested and listed for the application.
To that end, the WEEB clip itself has use limitations which should be adhered to:
The first listing the WEEB clips received was from ETL, or Intertek labs, testing was done to U.L. 467 for bonding, which is still a questionable decision because 467 does not provide any weather element to the testing. According to Intertek Engineering department the only modules that were tested under this application were Sharp modules, the racking that was tested only included Unirac, Direct Solar, and Pro Solar systems, so you can use the WEEBS to bond Sharp modules to any of those three mounting systems under the ETL listing.
The second "listing" they received was also via Intertek labs, Enphase had the clips tested to U.L. 1703 to allow the D/C GEC to provide equipment grounding for the rack, via the micro inverter.Contrary to popular belief the #8 D/C GEC still needs to be run to each inverter and the clip bonds the rack..
The last listing they received is not actulally a "listing", it is a U. L. "component recognition mark", what that means is that some modules were tested using the WEEBS, this component recognition mark only allows the WEEBS to be used on modules that were tested and listed by U.L.(and no other lab), and, it needs to be in the module manufacturer's installtion instructions to allow the WEEBS for module bonding (because U.L. vetts those instructions as well, so if it is in there U.L. tested them with the clips.)
Lastly, you could not use any clips for bonding any modules if there is going to be a need to use the module as an access panel to service micro inverters or j boxes because NEC section 690.48 "continuity of equipment grounding systems" requires jumpers to be installed on these modules.
So the bottom line is, all module bonding, including the use of the WEEB,S must be in accordance with the module manufacturer's installation instructions, and the listing/s indicated, and you can not use any bonding clips (including WEEBS) on a module that needs to be removed to access a j box or inverter.
Just my two cents.
Emmett, it depends on how you define "would it work." It would not be NEC compliant and it would not last. It would probably have a low resistance when first installed and provide a good ground, but remember that these need to last for 30+ years. That star washer might make a great ground for a couple of months but then corrosion of the washer and the surfaces on either side would add resistance until it was no longer providing a good ground. Then a few years down the line when there is a ground fault in the array and no ground connection someone goes out there and touches the module and is hurt or killed. Proper grounding will prevent this.
Stick with listed grounding devices that will make long lasting ground connections and provide safety for the life of the PV system.
I measured the resistance of an clear anodized mounting rail and there was no resistance to speak on, So I don't know where you are getting your information from but from my personal testing of the equipment I have in place it isn't an issue.
I wouldn't have any objections to using stainless steel internal+external lock washers to provide a ground connection between the equipment. The only reason for a grounding the metal frame is for potential lightning strikes, when you compare a webb clip to a star washer, the star washer clearly has the better teeth and greater contact area for surface penetration.
Ensuring the reliability of solar panel installations is paramount for their long-term performance. While traditional star-washers have been commonly utilized for electrical bonding and grounding, their inherent risks can compromise the integrity of the system over time.
One significant concern is water leakage, which arises when conventional washers degrade, failing to maintain a secure seal around the mounting brackets. This vulnerability exposes the panels to water ingress, posing a threat to the wiring and circuitry within.
Moreover, the use of traditional star-washers can contribute to structural issues. As these components corrode, they jeopardize the stability of the panel frame, potentially leading to instability and vibrations during windy conditions. Such vibrations exert undue stress on the frame, increasing the likelihood of cracks and structural damage.
Additionally, the efficiency of solar panels may be adversely affected by faulty star-washers. Corrosion-induced loosening can result in panel movement, thereby disrupting the optimal orientation for sunlight capture. This deviation reduces the amount of sunlight reaching the cells, consequently diminishing overall energy output.
To mitigate these risks, the adoption of SURE-BOND Environmentally Sealed Star-Washers is recommended. Specifically engineered for solar panel applications, these washers ensure a robust and watertight seal around the mounting brackets, safeguarding against water intrusion and structural compromise. By choosing SURE-BOND, installers can minimize the need for frequent washer inspections and replacements, enhancing the reliability and longevity of the solar array.