60C/70C Circuit Breaker Marking?

[xguard]

I don't recall seeing a circuit breaker before with a 60C/70C rating before. This circuit breaker is on a generator. I've seen them marked with the ambient temperature rating for the circuit breaker trip curve but this looks like it's referring to the lug temperature rating. I'd assume I'm limited to the 60C ampacity column. Thoughts? Any information would be appreciated, thanks.

 

[infinity]

The NEC would be either 60° C or 75° C so it's either mislabeled or it was designed for use not under the NEC. Those numbers would be the temperature rating of the terminals. The 40°C would be the ambient.

 

[augie47]

Here is a more clear picture. The 40° appears to relate to the UL Interrupting rating.
The terminations are 60/75

 

[xguard]

The NEC would be either 60° C or 75° C so it's either mislabeled or it was designed for use not under the NEC. Those numbers would be the temperature rating of the terminals. The 40°C would be the ambient.

Interesting. I found others marked 70C of this type. They're UL Listed. I do see that the UK has some 70C rated cables.

GENERAC GBU402-400A 400A 480V 2P 6K USED | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">This Generac GBU402-400A circuit breaker is a reliable and durable choice for any industrial or commercial electrical setup. With a maximum amperage of 400A and voltage rating of 480V, it is designed to provide superior protection against short...

www.ebay.com

Table 4D1A - Single-core 70°C Thermoplastic Insulated Cables, Non-Armoured, with or without Sheath

Table 4D1A - Single-core 70°C Thermoplastic Insulated Cables, Non-Armoured, with or without Sheath

www.cse-distributors.co.uk

 

[don_resqcapt19]

The pictures with the 70C marking say that are UL listed but do not say that they are listed to a product standard that applies in the US.
The label on the breaker itself says the breaker is listed for compliance with US and Canadian product standards.

 

[xguard]

The pictures with the 70C marking say that are UL listed but do not say that they are listed to a product standard that applies in the US.
The label on the breaker itself says the breaker is listed for compliance with US and Canadian product standards.

Thanks I didn't catch that. Does that mean it shouldn't be used in the US?

 

[don_resqcapt19]

Thanks I didn't catch that. Does that mean it shouldn't be used in the US?

It does mean that. Where a product is required to be listed by the NEC, it must be listed to a product standard that applies in the US.
However the 2023 code is the first edition of the NEC that actually requires breakers to be listed.

240.7 Listing Requirements.
The following shall be listed:
(1) Branch-circuit overcurrent protective device
(2) Relays and circuit breakers providing ground-fault protection of equipment
(3) Ground-fault circuit interrupter devices

Note that "branch-circuit overcurrent protective device" is a defined term that includes all of the breakers that we use.

Overcurrent Protective Device, Branch-Circuit. (Branch-Circuit Overcurrent Protective Device)
A device capable of providing protection for service, feeder, and branch circuits and equipment over the full range of overcurrents between its rated current and its interrupting rating. (CMP-10)

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