Encoder keeps cranes on track
July 1st 2007 Dinorwig hydroelectric
power station has SICK to
thank for a new
maintenance crane safety
system. To keep the
station's six generators in
reliable working condition,
every three years each
generator must be
dismantled and maintained.
Engineers have installed
a positioning system onto
each crane, with a PLC to
read the positional
information and
communicate with the other
cranes' PLCs via a radio
link. The system chosen for
this task was
SICK/Stegmann's Pomux
KH53 Linear encoder
system, a non-contact
absolute positioning
encoder that enables the
position of the cranes to be
calculated with millimetre
accuracy. The system
comprises two component
parts - the read head and
the measuring elements.
The construction of the
system enables multiple
read heads to be used with
a single run of measuring
elements, therefore it was
only necessary to install
one set of measuring
elements to serve all three
cranes. The positional data
is fed into the PLC in an
analogue format, the SSI
data was converted to a 0-
10V analogue signal using
an IV251 interface module. More articles from SICK (UK) Ltd: | 
