Rice Lake 920i USB Installation Manual V5.05 - Manual (Page 15)

Installation 9
2.0 Installation
This section describes procedures for connecting load
cell, digital I/O, and serial communications cables to
the 920i indicator.
Assembly drawings and replacement
parts lists for the universal model are included for the
service technician. See Section 11.12 on page 127 for
dimension drawings of the all models.
CAUTION
• Use a wrist strap to ground yourself and protect
components from electrostatic discharge (ESD)
when working inside the indicator enclosure.
• This unit uses double pole/neutral fusing which
could create an electric shock hazard. Procedures
requiring work inside the 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
to ensure all components are included and undamaged.
The shipping carton should contain the indicator, this
manual, and a parts kit. If any parts were damaged in
shipment, notify Rice Lake Weighing Systems and the
shipper immediately.
See Section 2.9 on page 18 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.
WARNING
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 Installing Sealed USB Connectors
For washdown environments, optional sealed USB
connectors are available for use with a specialized back
plate. To install the sealed USB connectors,
1. Align the watertight USB connectors with the
notches in the back plate. For optimal cable
routing, it recommended for the Type-A
connector to be on the left side and the Type-B
connector to be on the right side, as shown in
Figure 2-1.
Note
The hole in the back plate is keyed. Ensure the
key on the watertight USB connector is
inserted in the notch in the back plate as
shown below.
Figure 2-1. Sealed USB connectors on back plate
2. Fasten the watertight connectors so they are
flush with the back plate.
3. Connect the interface cables to the headers on
the USB card.
4. Install the backplate (see Section 2.6).
2.3.2 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 2-2). 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.