Connecting The Communication Cables - Navien NPE-180A Installation Manual

4.1.1 Piping Sizes and Considerations
When plumbing a cascading system, consider the following pipe
diameters and flow rates. Note that flow rates above 6.6 ft/s may
cause pipe erosion. These specifications may vary depending on
installation conditions.
ΔT=54ºF
Qty
Flow rate (GPM)
1 7.19
2 14.38
3 21.57
4 28.77
5 35.96
6 43.15
7 50.34
8 57.5
9 64.72
10 71.92
11 79.11
12 86.30
13 93.49
14 100.68
15 107.87
16 115.07
17 122.26
18 129.45
19 136.64
20 143.83
21 151.02
22 158.21
23 165.41
24 172.60
25 179.79
26 186.98
27 194.17
28 201.36
29 208.56
30 215.75
The table above is based on model NPE-240A.
Note
Water Pipe
Velocity (ft/s) Diameter (mm/in)
4.78 20A 3/4"
5.61 25A
5.54 30A 11/4"
5.21 40A 11/2"
6.53 40A 11/2"
4.49 50A
5.24 50A
6.00 50A
4.39 65A 2 1/2"
4.75 65A 2 1/2"
5.34 65A 2 1/2"
5.84 65A 2 1/2"
6.33 65A 2 1/2"
6.79 65A 2 1/2"
5.11 80A
5.44 80A
5.81 80A
6.14 80A
6.46 80A
6.83 80A
4.06 100A
4.25 100A
4.45 100A
4.65 100A
4.85 100A
5.05 100A
5.24 100A
5.44 100A
5.61 100A
5.81 100A

4.2 Connecting the Communication Cables

Up to 16 water heaters can be connected with Navien Ready-Link
communication cables. Select one of the water heaters in the
cascading system as the master water heater, and then connect the
other water heaters to it as slaves. Before making any connections,
ensure that the power is turned off to all water heaters.
Connect the Ready-Link cables to the J6 ports on the right side of
the front panel:
1"
2"
2"
2"
4.2.1 Configuring the Communication Settings
After connecting the Ready-Link communication cables, restore
3"
power to the water heater and turn on all water heaters using the
Power button.
3"
To configure the communication settings:
3"
3" 1. On the master water heater, press and hold the Diagnostic
and Up(+) buttons for more than 5 seconds. "MA.00" will
3"
appear on the display to confirm that this water heater is set as
the master.
3"
4"
4"
4"
4"
4"
4"
4"
4"
4"
4"
Installing a Cascading System 37