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MSEV Series and USHX Hardware Installation Manual Rev 1.7
6.
Form a daisy chain with the power lines by connecting the USHX power input cables (18 AWG
red/black wires) that are closest to the transformer on either side (USHX 3 and 4), as shown in
Figure 3-5. Use 16 AWG stranded copper wire for extensions.
The USHX power input wires are non-polar, so the wire ordering and colors are not
significant for the purposes of this step in the procedure. All connectors used between
the USHX, power source, and MSEV series valve should be UL approved. If the USHC
power input wires do not reach the system transformer add 16 AWG extensions to
the cables as needed.
7.
Run the power input wires from USHX 3 to USHX 2 and then from USHX 2 to USHX 1 as shown in
Figure 3-5.
8.
Run the power input wires from USHX 4 to USHX 5 and then from USHX 5 to USHX 6.
9.
The USB-to-RS485 adapter is used for USHX communications. Each USHX wiring harness includes
RS485 data communication wires (2-wire gray cord that contains a red and a black wire and the
green data ground wire).
10.
Create a daisy chain for the RS485 BUS as shown in Figure 3-5. Connect the gray RS485
communication wire of USHX 1 to USHX 2. Use similar communication cables when extensions
are required. Do not connect the data ground wire between USHX 1 and 2. It should remain
unconnected and protected with wire nuts and wrapped with electrical tape.
11.
Similarly connect USHX 2 to USHX3 and then USHX 3 to USHX 4. Repeat this pattern until USHX 6.
12.
For each transformer, only one USHX data ground wire should be connected to the RS485 adapter
signal ground input. As shown above in Figure 3-5, only the data signal ground wire (green wire)
of USHX 3 is connected to the RS485 adapter signal ground input.
13.
RS485 allows up to 32 nodes (or USHXs) to be connected on one channel (or daisy chain). Figure
3-6 below shows an example of three daisy chains of 12 USHXs each.
Figure 3-6 Multiple USHXs-to-RS485 hub/repeater networking
