Circling around to close the case that the breakers I suggested and have installed are not DC rated breakers - Maybe.
While I don't have extensive knowledge about all things electrical, I can research things (eventually).
The 2 pole breakers I have are the DZ47-63. This is the generic model number that is available from many sources. The product listing for my breakers says they are, "Suitable for isolation in accordance with industry standards: IEC EC 60898-1/GB10963.1."
I looked up
EC 60980-1. I'm having trouble finding the actual document for that standard. The link goes to the -2 standard. However, I did find this Schneider Electric blog entry that compares the -1 standard to another:
https://blog.se.com/energy-regulations/2014/02/06/iec-60898-1-iec-60947-2-tale-two-standards/
The table in that blog explicitly lists the 60980-1 standard as addressing only AC breakers.
There is also a 60980-2 standard (which my breaker does NOT reference) that has this in the summary:
Scope:
Clause 1 of IEC 60898-1:2015 is applicable except as follows:
Addition at the end of the first paragraph:
This standard gives additional requirements for single- and two-pole circuit-breakers which, in addition to the above characteristics, are suitable for operation with direct current, and have a rated DC voltage not exceeding 220 V for single-pole and 440 V for two-pole circuit-breakers, a rated current not exceeding 125 A and a rated DC short-circuit capacity not exceeding 10 000 A.
NOTE This standard applies to circuit-breakers able to make and break both alternating current and direct current.
Delete the last two paragraphs.
This makes it sound like the -1 standard did address both DC and AC circuit breakers. This confuses me.
ZHIMING GROUP is a another manufacturer of the DZ47-63 series. However, they explicitly
label their circuit breaker as DC. They also have a non-DC labeled product that has no mention of a DC rating and specifically references the IEC60898-1 standard. The one I bought does not have that DC designation in the label.
I'm still going with a different breaker, if for no other reason than I don't want to be in a gray area.