User Manual

WIRING INSTRUCTIONS
The MXU wiring instructions assume the utility meter with an encoder register has been installed and the
proper wire has been run to the MXU installation location. Three-conductor, 22 gauge, solid conductor
cable is recommended. (For meter installation, refer to the installation information included in Invensys
meter shipping cartons.)
1. Using the SR II security socket with ratchet wrench or nut driver, open the MXU enclosure by
removing SR II type security screw. Bottom part of enclosure will contain the MXU battery and top
part the electronics and connection wires. Connect the three wires from the encoder register to the
matching color wires on the MXU. If not already done, strip approximately 2" off outer jacket of the
encoder wire cable. The wire colors for each unit should be green, red, and black. Insert two matching
color wire ends – red to red, green to green, and black to black into a UY-2 gel-cap with the color
button of gel-cap facing away. (This provides a better view of wire positions inside the clear plastic
gel-cap enabling the installer to see the wires are completely and properly inserted.) Using gel-cap
pliers, squeeze the gel-cap. This will splice the two wires and release the waterproof gel to seal the
connection. The splice can be checked by pulling gently on the gel-cap while holding the wires to be
sure they are tight and secure. Repeat for the remaining two wire connections. If any of the wire
connections are not being used they should be capped at the end with a gel-cap. This is to prevent
water intrusion via wicking through the exposed wire ends.
2. Connect the battery to the MXU electronics. Using the gel-cap connecting technique described above,
connect the red and white stripe wire from the battery to the red and white stripe wire from the MXU
electronics. Repeat the procedure for the black and white stripe wire from the battery to the black and
white stripe wire from the MXU. Caution: DO NOT cross connect the black and white and the red and
white wires of the MXU and battery pack as this may cause damage to the MXU electronics.
3. (Optional) TouchRead ® Connection – The MXU includes a built-in TouchRead splitter connection to
allow the encoder register to be interrogated by both the MXU and a remote TouchRead System
sensor.
Wall Mount TouchPad – Using two-conductor or three-conductor wire cable and gel-caps, connect
wires to each of the green and white stripe wires from the MXU. Note: If three-conductor wire cable is
used, the third wire is not utilized for the TouchRead Connection. At the TouchPad connection,
connect the same two wires to the terminal screws on the back of the TouchPad. Caution: Be sure
there is no bare wire-to-wire contact. (The TouchRead connection is non-polarity sensitive and will
work as long as the same color wires are used at both ends of the connection. If three-conductor wire
is used, be sure the third “dead” wire is not mistakenly connected at either end.)
Pit-set Mount Sensor – The TouchRead pit-set sensor includes a factory-sealed three-conductor wire
cable. Proper wire connections are therefore important. To activate the pit-set TouchRead sensor,
use only the red and black wires from the sensor. Approximately 2" of the cable’s outer jacket must
be stripped from its end to access these wires. Then, using gel-caps, connect the black wire from the
sensor to one of the green and white stripe wires from the MXU. Next, connect the red wire from the
sensor to the other green and white stripe wire from the MXU.
4. Verify MXU operation prior to final assembly - To verify MXU reading, use a NexusData Handheld
Terminal (HHT) to interrogate the register and compare to the register odometer reading, register ID
number, and MXU ID number. To verify TouchRead reading, use a TouchRead visual reader to
display register odometer reading(s) and register ID number(s). If MXU does not function, check all
wire connections, redo the connections or change battery pack. (For complete TouchRead installation
and troubleshooting, see Invensys installation bulletins: TR-728, TR-997, and TR-998.)
5. After wiring connections are completed and MXU operation is verified, align guides of top and bottom
parts of MXU and close, bringing the connection wires out the front side, using the wire pass-thru
guides located on either side of the security screw. Secure the top and bottom parts of the MXU using
the security screw. Caution: DO NOT over-tighten security screw.