You are correct in your thinking. RVSS (Reduced Voltage Solid State Starters) do not have a NEMA size rating in the same way that full voltage starters do.Here's why: NEMA Sizes are Based on Contactor Size & Horsepower

NEMA sizes for full voltage starters (NEMA Size 0, 1, 2, etc.) are primarily based on the physical size of the contactor and its horsepower rating at a specific voltage. These are standardized values.

RVSS Focus on Current Control

RVSS units control the voltage (and therefore current) applied to the motor during startup. Their design is based on the current requirements and features like voltage ramping, current limiting, and other algorithms. Horsepower rating is still a consideration, but the current control capability is the defining factor.

Vendor-Specific Designs

RVSS design and components, such as thyristors (SCRs) and control circuitry, differ significantly between manufacturers. Each vendor has their own model numbers and specifications optimized for different applications and motor sizes.

Ampere Rating is Key

The most important specification for an RVSS is its continuous current rating (Amperes). You need to select a starter that can handle the full load amps (FLA) of the motor.

No Direct NEMA Equivalence

There isn't a direct translation between a NEMA size and an RVSS model. You can't say a "NEMA Size 2 is equivalent to an RVSS Model XYZ."

In summary

Don't expect a NEMA size rating on an RVSS starter submittal. Focus on the RVSS's continuous current rating (Amps) and ensure it meets or exceeds the motor's FLA. Verify that the RVSS meets the application requirements: voltage, horsepower, starting torque requirements, duty cycle, and any specific control features needed. Review the vendor's specific RVSS model specifications and ensure they are appropriate for the motor and application.

Therefore, your assessment is correct. The vendor is likely specifying the RVSS based on their specific model and its current rating, not a NEMA size.

When reviewing the submittal, make sure the following are clearly specified: Vendor and Model Number Continuous Current Rating (Amps) Voltage Rating Horsepower Rating (though less important than Amps) Fault Current Withstand Rating (SCCR) - Very important for safety and coordination. Control Voltage Enclosure Type* Any special features or options (e.g., bypass contactor, communication protocols, overload protection)Good luck! Flag for review