Cooper Instruments XAA 911 Installation Manual

XAA 911 FOUR-CHANNEL SIGNAL TRIM SUMMING BOX

1.0 INTRODUCTION

The XAA 911 is an excitation or signal trim junction box that can accommodate two, three or four cells and are
used primarily in floor and hopper scales. Each model also has the capability to extend to more than four load
cells using an expansion connector. All models have a new Prevent® breather vent which inhibits the buildup of
pressure caused by sudden temperature or environmental changes. When correctly installed, all models can
withstand 900 PSI water pressure.

All terminals will function properly without modification. However, load cell output can be individually trimmed
with potentiometers, which is further explained in Section 4.0.

1.1 Model Designations

The XAA 911 junction box comes in several different models including stainless steel for the small junction box
and a FRP enclosure for the mid-range junction box. Applications vary from use in floor scales to hoppers so
selection can vary from a light capacity junction box to a mid-range capacity junction box. XAA 911 models
include:

• 4-Channel Excitation Junction Box w/ Expansion in SST Enclosure

• 4-Channel Signal Trim Junction Box w/ Expansion in SST Enclosure

• 4-Channel Excitation Junction Box w/ Expansion in a FRP Enclosure

• 4-Channel Signal Trim Junction Box w/ Expansion in a FRP Enclosure

2.0 XAA 911 JUNCTION BOX MOUNTING PROCEDURE

The XAA 911 junction boxes include tow different sizes:

• 4-Channel small enclosure

• 4-Channel mid-range FRP enclosure

The following sections describe the correct mounting procedure used for each.

2.1 Mounting the Small Junction Box

The junction box should be mounted in a location
that is convenient for servicing and away from
standing water. Try to mount the enclosure in a
location so that the load cell cables need not be
cut nor length added. Load cell output is
temperature compensated for the supplied cable
length. Altering that length can change the cell’s
signal output.

Depending on the mounting surface, the
enclosure is attached using four pan-head
screws, bolts, or other suitable fasteners. Figure
1 (right) shows dimensions for mounting the
enclosure.

Figure 1. Enclosure Dimensions

CF 60 1 91909 ©2006

2.2 Mounting the Mid-Range Junction Box

The junction box should be mounted in a location that is
convenient for servicing and away from standing water. Try
to mount the j-box in a location so that the load cell cables
need not be cut, nor length added. Load cell output is
temperature compensated for the supplied cable length.
Altering the length can change the cell’s signal output.

Depending on the mounting surface, the enclosure can be
attached using four pan-head screws, bolts or other
suitable masonry fasteners. Figure 2 (right) shows the
dimensions for mounting the enclosure.

Figure 2. Enclosure Dimensions

3.0 WIRING THE JUNCTION BOX

The XAA 911 has been designed to connect and trim up to
four load cells per board. However, it is possible to use this
box with other combinations. Use the expansion port on the
main board (shown below) to connect multiple junction
boxed in series to accommodate application that have
more that four load cells.

After determining the wiring pattern, route the load cell
cables through the nylon cord grip assemblies and leave
the grips loose until final closure. Before connecting load
cell wires to the terminals, strip the wire insulation back ¼”
to expose the wire. The spring-loaded terminals will
accommodate 12 to 28 gauge wire. To connect the load
cell and indicator wires to the appropriate connectors, push
in the quick-connect lever with a small screwdriver. While
holding in the lever, insert the appropriate wire into the
exposed wire opening. Release the screwdriver to allow
the spring-loaded gate to close and lock the wire in place.

The indicator terminal strip is used to connect the main cable to the indicator. Determine the indicator’s load cell
input connections from the operating manual. Run a cable from your indicator terminal into the junction box through
the larger cord grip and make the connections on the indicator terminal using the same procedure a s inserting load
cell cables to the appropriate connectors.

Figure 3. Expansion Port Wiring Location

4.0 TRIMMING PROCEDURE

Trimming is a process of equalizing the output from multiple individual load cells. If needed, load cell output can
be individually trimmed with potentiometers.

CF60 2 91909 ©2006