September 2002
67970
IQ plus
®
355 Digital Weight Indicator
EMI Suppression Ferrite Installation
To reduce susceptibility to radiated EMI (electromagnetic interference) install a ferrite inside the indicator
enclosure for both load cell and serial cables.
Use the following procedure to install the ferrite (PN 66730) which is included in the IQ plus 355 parts kit.
1. Ensure power to the indicator is disconnected, then place the indicator face-down on an antistatic work
mat.
2. Remove the screws that hold the backplate to the enclosure body, then lift the backplate away from the
enclosure.
3. Strip cable insulation and shielding per cable grounding instructions, Section 2.3.1, PN 66503, I
Q plus
355 Installation
Manual
(and shown in Figure 1). Ensure there is sufficient cable lengths to loop once
around the ferrite, before reaching the cable connectors inside of the indicator (shown in Figure 2).There
should be 14" (36cm) for the load cell cable and 21" (54cm) for the serial communications cable. Tighten
grounding clamp nuts.
Figure 1. Grounding Clamp Attachments
Figure 2. Loop Diagram of Ferrite
Cord grip
Insulated cable
Foil
(silver side out)
Grounding clamp
Shield wire
(cut)
Length of foil before folding
back on cable insulation
Cut insulation here
for foil-shielded cables
Braid
Cut insulation here
for braided cables
NOTE: Install lockwashers
first, against backplate,
under grounding clamp
Ferrite
E n c l o s u r e
backplate
G r o u n d i n g
clamps
Kep nuts
