Is a bank of cables, with a dust layer evenly distributed on both side
s of the cables, more or less dangerous than a bank of cables with the
same amount of dust all on one side? This question is answered by exp
licitly calculating the critical conditions for spontaneous ignition f
or each case. In the usual situation, with low dust conductivity, the
asymmetric situation is more stable. When the conductivity of the ''du
st'' becomes comparable to that of the cable, the stability is reverse
d.