An ePO server with the Support Center extension installed executes queries against the SQL database. In certain circumstances, some of these queries aren't closed and remain in a sleeping state. This action in turn holds a connection open, which can cause tempdb to grow excessively.

The queries in question are as follows:

SELECT COUNT(1) FROM EPORegisteredApacheServers AS erac INNER JOIN EPOServerInfo AS esi ON erac.ComputerName = esi.ComputerName WHERE erac.Enabled=1 AND erac.LastUpdate > DATEADD (MINUTE, -5, GETUTCDATE())
And
Select AutoID, ProxyID, Address from [EPORepositoryProxyExclusionList] where ProxyID='1'

New instances of these queries are executed on a scheduled basis, so you might see multiple instances of these sleeping queries.