This is an interesting situation. Let's break down the possibilities and address your questions.

Possible Reasons for the Rivets



NFPA 70 (NEC) 230.71 Compliance (Six Disconnect Rule)

This is the most likely culprit, especially given the original configuration with only six breakers and no upstream main disconnect. Section 230.71 of the National Electrical Code (NEC) generally limits the number of service disconnecting means to six. Since this panel was the service disconnect, the rivets may have been intentionally installed to ensure compliance with the six disconnect rule, given the potential for the panel to accommodate many more breakers.

Buswork Capacity Concerns (Less Likely)

While it's possible, it's less likely Eaton installed the rivets due to buswork capacity concerns. Panelboards are typically designed with busbars capable of handling the advertised amperage. Unless there's significant evidence of overloading or overheating, this reason is less probable, especially considering your total load remains far below the 800A rating. Additionally, they would likely have other solutions to limit the current if this were the case.

Original Installer Modification

It's plausible the original installer, understanding the six disconnect rule and the potential for more breakers, added the rivets themselves to ensure code compliance and prevent future issues with inspectors. They might have chosen this method as a field solution rather than replacing the entire panelboard.

Factory Default

It's possible that Eaton added these rivets from the factory and offered a way to remove them after an official inspection. Eaton's documentation would need to be checked for this.

Analysis and Recommendations


Documentation Review

Thoroughly review the Eaton PRL 4 panelboard documentation, including the instruction manual, UL listing information, and any available engineering data sheets. Look for any mention of restricted breaker positions, the six disconnect rule, or field modifications. Contact Eaton directly with the serial number and pictures to get their official stance on the rivets and whether removing them would void the UL listing.2.

Consult with Eaton's Engineering Department

This is the most crucial step. Contact Eaton's technical support or engineering department. Provide them with the panelboard model number, serial number, and the pictures. Explain the situation and ask them specifically about the rivets, their intended purpose, and the potential impact on the UL listing if they are removed. Get their official, documented response in writing.3.

Inspect the Buswork Thoroughly

Carefully inspect the buswork behind the breaker locations. Look for any signs of overheating, damage, or unusual connections. Ensure that the busbars are adequately sized for the panel's 800A rating and the proposed load.4.

Consider a Separate Panel

Given that you are adding a service disconnect upstream, you could replace this existing panel to expand your services for the addition. This would be the safest way to ensure no UL listing issues.5.

Inform Your Inspector

Discuss the situation with your local electrical inspector before removing any rivets. Get their opinion on whether removing the rivets would violate any code requirements or compromise the panelboard's safety.

Compromising the UL Listing?Yes, removing the rivets could compromise the UL listing, especially if Eaton did not intend for them to be removed. Here's why: UL Listing Scope

The UL listing applies to the panelboard as it was originally manufactured and tested. Any modifications to the panelboard, including removing rivets, could potentially invalidate the listing, unless Eaton explicitly states otherwise.

Impact on Safety

The rivets may be part of the panelboard's design to ensure proper breaker spacing, prevent overloading, or maintain adequate insulation. Removing them could potentially compromise the panelboard's safety and increase the risk of electrical hazards.

Important Considerations



Safety First

Always prioritize safety when working with electrical equipment.

Code Compliance

Ensure that any modifications to the electrical system comply with all applicable codes and regulations.*

Documentation is Key: Keep detailed records of all work performed, including documentation from Eaton and approvals from the electrical inspector.In summary, start with thorough documentation review and contact Eaton directly for their official stance on the rivets. Consult with your local electrical inspector before making any modifications. Removing the rivets without proper authorization could compromise the UL listing and potentially create safety hazards. Flag for review