We currently have a 100 amp main breaker box and need to add an outside disconnect to meet code requirements. We would like to use. 150 amp single pole disconnect since we plan to upgrade to 150 at a later date. Service company said existing line comings into house is only good for 100-110 amps, so need to know if there are any issues with using the 150 amp disconnect with the lower rated panel until we get the service line and main panel upgraded.
Futile, since everything will need to be upgraded to go 150A. Including service entrance wires in and out of the meter and to the old main.
I agree, I've never heard of a 150A single-pole disconnect. Note that the cheap Alibaba crud found on eBay and Amazon Marketplace are unsafe and illegal, and will result in inspection failure and the power company refusing to energize it.
I would actually "lean in" to the bigger amps thing and instead of a disconnect, use a 200A panel with some breaker spaces at the meter. Make one of them a 100A breaker feeding the old panel. Now you don't need to replace the old panel. That's $2000 you never need to spend :) And when you upgrade service later, big stuff can go in the 200A panel.