fieldbox shouldhavea minimum indexof protection of IP, 55 allowingdust to
be removedfromthe enclosure'sexterior by watercleaning.
Specialattentionshould be givento the construction of doorsof fieldboxes.
In general, thereshouldbe a waterseal (PVCstrip)betweenthe doorand the
fieldbox.The capillaryactionshould be reducedby providing a foldedlip along
the top insideedgeof the door. For metalenclosures,the doorshouldbe
provided with a stud-welded earth terminal. Internal to the body of the
enclosure, fourstud-welded gearplatefixingsand a furtherstudweldfor the
earthterminalshouldbe provided. In orderto prevent condensate dripping from
the box into the product, fieldboxesshould not be placed in or abovethe contact
area.Furthermore, fieldboxes should be located suchthateasyaccess for
maintenance and cleaning is practicable.
Boxesmountedon the wallor on a frameshould be:
∑ sealedto the wallor framewitha foodstandardsilicon sealantso that soil
trapsare not createdat the rear of the fieldbox,or
Fig. 15.4 Stainlesssteelcabinetplaced100 mm fromthe floor.Improvingthe hygienicdesignof electricalequipment 249