<s>
Diesel	B-Device
rotary	I-Device
uninterruptible	I-Device
power	I-Device
supply	I-Device
devices	O
(	O
DRUPS	B-Device
)	O
combine	O
the	O
functionality	O
of	O
a	O
battery-powered	O
or	O
flywheel-powered	O
UPS	O
and	O
a	O
diesel	O
generator	O
.	O
</s>
<s>
Typically	O
a	O
DRUPS	B-Device
will	O
have	O
enough	O
fuel	O
to	O
power	O
the	O
load	O
for	O
days	O
or	O
even	O
weeks	O
in	O
the	O
event	O
of	O
failure	O
of	O
the	O
mains	O
electricity	O
supply	O
.	O
</s>
<s>
The	O
main	O
advantages	O
of	O
DRUPS	B-Device
equipment	O
compared	O
to	O
battery-powered	O
UPS	O
combined	O
with	O
a	O
diesel-generator	O
are	O
the	O
higher	O
overall	O
system	O
energy	O
efficiency	O
,	O
smaller	O
footprint	O
,	O
use	O
of	O
fewer	O
components	O
,	O
longer	O
technical	O
lifetime	O
(	O
no	O
use	O
of	O
power	O
electronics	O
)	O
and	O
the	O
fact	O
it	O
does	O
not	O
result	O
in	O
chemical	O
waste	O
(	O
no	O
use	O
of	O
batteries	O
)	O
.	O
</s>
<s>
The	O
main	O
disadvantages	O
of	O
DRUPS	B-Device
equipment	O
are	O
a	O
more	O
frequent	O
maintenance	O
regimen	O
due	O
to	O
the	O
number	O
of	O
moving	O
parts	O
.	O
</s>
<s>
DRUPS	B-Device
are	O
also	O
typically	O
installed	O
in	O
external	O
buildings	O
due	O
to	O
noise	O
concerns	O
from	O
the	O
generators	O
.	O
</s>
<s>
A	O
DRUPS	B-Device
can	O
provide	O
a	O
ride-through	O
time	O
of	O
15	O
–	O
40	O
seconds	O
.	O
</s>
