Here is the notification from our Seattle datacenter staff. Connectivity interruption is expected.
On March 20th between 4:00pm and 9:00pm, there will be emergency maintenance on an electrical panel in one of our Seattle datacenters. During the maintenance, there will be a brief outage of up to 30 minutes as the main power leg is replaced. Due to the load on the UPS,all equipment being fed from the panels will need to be shutdown during this maintenance. Your equipment is not fed via this panel, so your equipment will not need to be shutdown however, the equipment that provides your network connectivity is. So while your equipment will not be powered down you will lose connectivity during the maintenance window.