16
MSEV Series and USHX Hardware Installation Manual Rev 1.7
14.
At the end of each daisy chain, install a 120 Ω termination resistor, as shown in Figure 3-6.
15.
Procure an isolated RS485 hub/repeater. If an isolated hub/repeater cannot be found, then it is
necessary to install an isolator for each channel.
The communication cable must be kept away from high-strength electric and
magnetic fields such as those emitted from USHX and MSEV series valve power wires,
110/220 VAC wires, fan motors, relay coils, etc.
The exposed metal on the ground wires of the remaining controllers should be
covered with electrical tape.
16.
Connect the isolated RS hub/repeater to the isolated RS485 adapter box. Connect the box to the
computer via a USB port.
17.
Connect the two PWM output wires (two 18 AWG white wires) of each USHX to the electrical
connections of corresponding MSEV series valve. These wires are non-polar.
18.
Additional general purpose wires (20 AWG brown/purple wires), if they exist on the harness, must
remain unconnected, be terminated using wire nuts, and wrapped with electrical tape so that
they do not form short circuits with each other or any other wires or metal surfaces.
19.
Tape any dangling wires to existing structures such as copper and water lines with at least 4-5
sections of electrical tape each. Use zip ties on top of the electrical tape in a neat and organized
manner to further secure the wires.
Ensure that all cables are distanced from fans, high voltage wires (120-208 VAC), and
potential areas of water. Ensure that any bare cable leads are covered with electrical
tape and do not touch other wire leads or any metal structures.
20.
The electrical wiring for Multiple USHCs and MSEV series valves or Multiple USHSs is now
complete.
21.
Refer back to
Section 2.2 (Installing the USHX), Step 17
and complete the remaining steps to
finalize the hardware installation process.
