You've hit on a key point of confusion and brought up some excellent questions regarding multi-position meter sockets. Let's break down the information and address your concerns.

Understanding Meter Socket Ratings and the Missing Main Bus Rating



Individual Socket Rating vs. Main Bus Rating

You're absolutely correct. The 100/150/200A rating in the Eaton catalog (and similar ratings in other manufacturers' catalogs) typically refers to the

individual socket's continuous current carrying capacity. This is the maximum current that can safely flow through each meter socket position. Why No Explicit Main Bus Rating (Sometimes)

The Eaton catalog's lack of an explicit "main bus rating" is somewhat common in older style horizontal ganged meter socket offerings. There are several reasons for this:

Design Assumptions

These older style designs often implicitly assume a certain level of diversity (load not occurring at same time) across the individual meters. The main bus is sized based on statistical load profiles rather than the sum of all individual socket ratings.

Engineering Judgment Required

Manufacturers expect the installer/engineer to perform load calculations and use engineering judgment to determine if the implicit main bus capacity is adequate. They are providing the individual socket ratings as a starting point.

"Overkill" Concerns

In many residential applications, the diversity of load is such that sizing the main bus to handle the full sum of individual socket ratings would be excessively expensive and physically large.

Catalog Variations

As you correctly pointed out the Square D catalog does provide main bus ratings. This can vary by manufacturer and product line.

Important Implication

The absence of a clearly stated main bus rating means it is

crucially important to perform a thorough load calculation for the entire building, considering diversity factors, and then contact the manufacturer's technical support or an experienced electrical engineer to confirm the adequacy of the meter socket's main bus for your specific application.

Determining Main Bus Capacity for Your Application


Accurate Load Calculation

You've already done this with your 450A calculated electrical service.2.

Diversity Factor Consideration

In a 5-unit multifamily dwelling, you can apply a diversity factor, but be very conservative, and base it on documented guidelines from sources like the National Electrical Code (NEC) or local utility requirements. Be sure to not use any diversity that can be proven to not be there(Such as the case of Electric vehicle charging).3.

Contact Eaton's Technical Support (CRITICAL)

Provide Eaton's technical support the exact part number of the meter socket you are considering and your detailed load calculation (450A total, including all individual loads). Ask them specifically: "What is the documented, continuous current carrying capacity of the main bus in this meter socket under my specific loading conditions? Is it adequate for my 450A calculated load?" Keep a written record of their response for your project documentation.4.

Consider an Independent Review

If you have any doubts about the manufacturer's response or your load calculations, consult with a qualified professional electrical engineer for an independent assessment.

Regarding Discontinuation and Modern Alternatives



Not Completely Discontinued, but Less Common

You are right; horizontal ganged meter sockets are less commonly seen in new construction. Modern trends favor more compact and integrated solutions.

Reasons for the Shift



Space Efficiency

Meter packs and meter banks are generally more space-efficient.

Integrated Features

Modern meter packs often include features like integrated service disconnects, surge protection, and communication capabilities.

Code Compliance

Achieving compliance with NEC 2020 requirements (230.62 & 230.71) is often simpler and more cost-effective with meter packs or meter banks that have built-in service disconnects.

Your NEC Concerns

You are correct in identifying the NEC 2020 requirements. Separating the service disconnects into each unit is a must.

Recommendations



Meter Packs/Meter Banks Are Generally Preferred

For new construction, a 6-position meter pack (with a standalone main service disconnect if needed for the utility requirements) or a 1MM series meter bank with a main service breaker section is almost always the superior choice.

Advantages of Meter Packs/Meter Banks

Easier NEC 2020 compliance (integrated service disconnects). Clearer main bus ratings and readily available documentation. Space savings. Potentially lower overall cost (considering labor and materials). Improved aesthetics.

When Horizontal Ganged Sockets Might Be Used

These may still be viable for: Retrofit situations where existing conduit and service entrance locations constrain the installation. Specific utility requirements that mandate a particular socket configuration. Situations where you need to maintain a very specific visual aesthetic for historical reasons.

Additional Notes Never assume that the service overcurrent protection for a meter socket can protect downstream. Always check with the local utility and AHJ (Authority Having Jurisdiction) to confirm equipment and installation requirements. When sizing equipment, always check the nameplate to be sure the product meets the requirements of your specific application.

In Conclusion:

While you could* potentially use the older-style horizontal ganged meter sockets, the risks of inadequate main bus capacity, combined with the complexities of NEC 2020 compliance, strongly suggest that you seriously consider a modern meter pack or meter bank solution. Doing so will likely save you time, money, and potential headaches in the long run. Always prioritize safety and code compliance! Flag for review