Snapping spkes

After a fabulous 250 miles on my tandem TerraTrike I encountered a major problem and need advice on how to proceed. I was a block away from my house and heard a strange noise and upon checking it out I noticed a broken spoke on my e hub. I limped home at 2 mph and by the time I reached home a total of 10 spokes were broken. I got a new set of spokes and was told to monitor the spokes better. My bike shop fixed the spokes and with in 30 days they blew out again. I ride every day. I purchased the heavy duty wheel package which is rated at 600 lbs (?). We are well below that and I am wondering if there maybe another solution such as a mag wheel or welding steel bars on the wheel. Any solutions would be greatly appreciated. Since my last wheel purchase a few years back, I have been rated 100% by the VA and the exercise has been a great help with my everyday life.
Thanks in advance,
Geege Ferretjans

Recommend brass spoke washers at the "shoulder" of the spokes where they emerge from the spoke holes in the hub washers. That is usually where they break, in my experience. And buy good double butted spokes like Sapim, or even rebuild with 12 gauge spokes.