Rice Lake 920i Installation Manual V3.07 - Manual (Page 13)

Installation 7
2.0 Installation
This section describes procedures for connecting load
cell, digital I/O, and serial communications cables to
t h e
9 2 0 i i n d i c a t o r. A s s e m b l y d r a w i n g s a n d
replacement parts lists for the universal model are
included for the service technician. See Section 10.12
on page 117 for dimension drawings of the all models.
• Use a wrist strap to ground yourself and
protect components from electros tatic
discharge (ESD) when working inside the
indicator enclosure.
• This unit uses double pole/neutral fusing
which could create an electric shock hazard.
P r o c e d u r e s r e q u i r i n g w o r k i n s i d e t h e
indicator must be performed by qualified
service personnel only.
• The supply cord serves as the power
disconnect for the
920i . The power outlet
supplying the indicator must be installed near
the unit and be easily accessible.
2.1 Unpacking and Assembly
Immediately after unpacking, visually inspect the 920i
t o e n s u r e a l l c o m p o n e n t s a r e i n c l u d e d a n d
undamaged. The shipping carton should contain the
indicator, this manual, and a parts kit. If any parts
were damag ed in sh ipm en t, notify Rice Lake
Weighing Systems and the shipper immediately.
See Section 2.10 on page 14 for parts kit contents.
2.2 Enclosure Disassembly
The indicator enclosure must be opened to install
option cards and to connect cables for installed option
cards.
The 920i has no on/off switch. Before
opening the unit, ensure the power cord is
disconnected from the power outlet.
Ensure power to the indicator is disconnected, then
place the indicator face-down on an antistatic work
mat. Remove the screws that hold the backplate to the
enclosure body, then lift the backplate away from the
enclosure and set it aside.
2.3 Cable Connections
The universal model of the 920i provides six cord
grips for cabling into the indicator: one for the power
cord, five to accommodate cabling for option cards.
Install plugs in all unused cord grips to prevent
moisture from entering the enclosure.
2.3.1 Cable Grounding
Except for the power cord, all cables routed through
the cord grips should be grounded against the
indicator enclosure. Do the following to ground
shielded cables:
• Use the lockwashers, clamps, and kep nuts
provided in the parts kit to install grounding
clamps on the enclosure studs adjacent to cord
grips. Install grounding clamps only for cord
grips that will be used; do not tighten nuts.
• Route cables through cord grips and
grounding clamps to determine cable lengths
required to reach cable connectors. Mark
cables to remove insulation and shield as
described below:
• For cables with foil shielding, strip insulation
and foil from the cable half an inch (15 mm)
past the grounding clamp (see Figure 2-1).
Fold the foil shield back on the cable where
the cable passes through the clamp. Ensure
silver (conductive) side of foil is turned
outward for contact with the grounding
clamp.
• For cables with braided shielding, strip cable
insulation and braided shield from a point just
past the grounding clamp. Strip another half
inch (15 mm) of insulation only to expose the
braid where the cable passes through the
clamp (see Figure 2-1).
Figure 2-1. Grounding Clamp Attachment for
Foil-Shielded and Braided Cabling
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 enclosure,
under grounding clamp