shouldnot be usedin dry production areas, where smallwiretraysare a better
solution, to allowdry cleaning.
15.4.5 Cables and flexibleinstrument air tubes
Cables and flexible instrument air tubes shouldhavea smooth outerpoly(vinyl-
chloride) (PVC) or polypropylenesheath,as applicable, suchthat theyare easy
to clean where not protectedby cableladders,wiretraysor conduit. Whentwo
singlecablesor tubes are routedtogether in paralleltheyshouldnot be tied to
eachother in orderto prevent the build-upof soil and to easecleaning.
15.4.6 Connectionsto cabinets and fieldboxes
To enable manualcleaningand visual inspectionof enclosuresurface areas on
whichsoil can accumulate, it is necessary to keeptheseareasas smoothas
Fig. 15.3 Cablesbesideeachotheron a stainlesssteelcableladder.Notethe closed
supportsand cleanableconduits.Problem:the horizontalpartsand omegarail of the cable
ladder!
Improvingthe hygienicdesignof electricalequipment 247