  We investigate to which extent a many-body Bloch-Redfield master equation
description of quantum transport is consistent with the exact generalized
equilibrium conditions known as exchange fluctuation theorems. Thereby we
identify a class of master equations for which this is the case. Beyond this
class, we find deviations which exhibit characteristic scaling laws as
functions of the dot-lead tunneling, the inter-dot tunneling, and the
temperature. These deviations are accompanied by an increase of lead energy
fluctuations inherent in the Bloch-Redfield equation beyond rotating-wave
approximation. We illustrate our results with numerical data for a double
quantum dot attached to four leads.
