I just got ahold of an Antminer L3+ and wondering about something in my hashrate.

The hashrate for my machine is 500MH/s and according to antpool it's about that...but I keep getting weird dips and even complete drops of hash rate in both my hourly and minutely charts:

Hourly Chart: https://i.gyazo.com/9a78cb6fe29fa3dffeaace9ca1889f51.png
Minutely: https://i.gyazo.com/7f6e9bd7ba92fa53b8003cee5f9c8642.png

Is this drop off something I can track down? Is it normal?