Ring connector max amps?

Question

I bought some ring connectors (crimp) for a fairly high-current application. The connectors don't say anything about current rating, though. (They're Gardner Bender 15-096, btw.) I haven't found any mention of ring connector current rating in general, on the internet, either. Is it just assumed that they can carry however much current their matching gauge of wire can carry?

Answer 1

A search on UL's Product iQ database for 'gardner bender ring terminal' led to a file for ECM Industries, LLC (owner of the Gardner-Bender brand) and does mention the 15-096 part number (source). It seems those are tested to UL's product code ZMVV "Wire Connectors and Soldering Lugs."

UL's "White Book" describes the standard. I happened upon the 2013 edition in which the ZMVV section includes the following.

Ampacity level rating:

A. Equipment use — Equipment wiring requirements may restrict the sizing, ampacity and temperature ratings of connected conductors. Equipment requirements may limit 90°C or higher-rated conductors to 60 or 75°C ampacity in accordance with Electrical Equipment for Use in Ordinary Locations (AALZ).

B. General use — Connectors rated 75°C are intended for use at ampacities not greater than those for 75°C-rated conductors, and connectors rated 90°C are for use at ampacities not greater than those for 90°C-rated conductors. Connectors may be marked with ‘‘75C’’ or ‘‘90C’’ to represent these levels. Alternatively, these rating levels may be repre sented by a 7 or 9 associated with the marking ‘‘CU,’’ ‘‘AL’’ or ‘‘AL-CU,’’ e.g., ‘‘AL9,’’ ‘‘AL9CU,’’ ‘‘AL7CU,’’ ‘‘CU7,’’ ‘‘CU9.’’ Connectors not marked with an ampacity number 7 or 9 have an assumed level per the following table. Use of higher-temperature-rated conductors is not prohibited, provided the ampacity levels continue to be based on the 75 or 90°C ratings.

Connectors are rated and marked as follows:

| Type of Connector      | Rated For | Wire Range | Temp Marking | Rating|
|:-----------------------|----------:|-----------:|-------------:|------:|
|Terminal (CU body)      |CU only    |All         | Not marked   | 90    |
|Terminal (AL body)      |CU only    |All         | 75 or 90     |As marked@|
|Terminal                |AL or AL-CU|All         | 75 or 90     |As marked@|
|Splicing wire           |CU only    |30-6        | Not marked   | 90    |
|Splicing wire (CU body) |CU only    |4 and larger| Not marked   | 90    |
|Splicing wire (AL body) |CU only    |4 and larger| 75 or 90     |As marked|
|Splicing wire           |AL or AL-CU|30-6        | Not marked   | 75    |
|Splicing wire           |AL or AL-CU|4 and larger| 75 or 90     |As marked|

@ Terminal connectors rated for 6 AWG or smaller conductors may have the markings on the connector, the unit container, or on an information sheet packed in the unit container.

The terminals in question are rated for 75°C but it's not clear whose ampacity chart we should consult. If we go by the 2020 NEC Table 310.16 and use the 75°C column, then 6 AWG copper and these ring terminals have ampacity of 65 amps.