Can’t be 15A, can it?
Most likely. It’s possible that it was for something separately metered, like a water heater or something small. It’s rated for single phase.
The 15 amps refers to the testing procedure and has nothing to do with the operating rating of the meter.
As far as the can, it’s tough to say without looking inside at the lugs, service conductors and maybe a label. Hopefully someone familiar with that design has an idea of what that can is rated to handle.
Could it be for a yard light
This may be of some help;
Found on this Website,
ELECTRIC METERS - as Indicators of Service Ampacity
The meter itself is also a consideration when determining the service ampacity of an electrical system.
Most modern meters for single family homes have the designation “CL200” somewhere on their face, which indicates they are rated for up to a 200 Amp service.
The CL200 rating may not limit these to 200 amps. Cramer reports finding larger services with CL200 meter bases.
Inspectors will also occasionally find a “CL10” meter which is a transformer-rated meter for large houses with larger electrical systems or two separate main panels.
Some older meters have other designations such as “15 Amps” on their face. This was their test rating. These meters are only usable on systems up to 100 Amps.
Some older meters were also designated as “30 Amps” on their face and these are compatible with 200 Amp services. For example, one may occasionally find an older house with an upgraded 200 Amp service that still has an old 15 Amp meter plugged into a new meter base. This meter is not really compatible with the system and should be replaced. Since the responsibility for the meter varies throughout the country, inspectors should contact the local electric utility for their policies and procedures concerning meters.
Thanks! You da man Marcel!