Connecting The Communication Cables; Configuring The Communication Settings - Navien NCB-150E Installation & Operation 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 Water
Qty Flow rate Velocity
(GPM) (ft/s)
1 7.19 4.78
2
14.38 5.61
3 21.57
5.54
28.77
4 5.21
35.96
5 6.53
6 43.15 4.49
7 50.34 5.24
8 57.5 6.00
9 64.72 4.39
10 71.92 4.75
11 79.11 5.34
12 86.30 5.84
13 93.49 6.33
14 100.68 6.79
15 107.87 5.11
16 115.07 5.44
17 122.26 5.81
18 129.45 6.14
19 136.64 6.46
20
143.83 6.83
21
151.02 4.06
22
158.21 4.25
23
165.41 4.45
24
172.60 4.65
25
179.79 4.85
26
186.98 5.05
27
194.17 5.24
28 201.36
5.44
29 208.56
5.61
30 215.75
5.81
The table above is based on model NCB-240E.
Note
Pipe Diameter (mm/in)
20A /
3
in.
4
25A
1 in.
30A /
11
in.
4
/
11
40A in.
2
/
11
40A in.
2
2 in.
50A
2 in.
50A
2 in.
50A
2 /
65A 1 in.
2
2 /
1
65A in.
2
2 /
1
65A in.
2
2 /
1
65A in.
2
2 /
1
65A in.
2
2 /
1
65A in.
2
3 in.
80A
3 in.
80A
3 in.
80A
3 in.
80A
3 in.
80A
3 in.
80A
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.
100A 4 in.

4.2 Connecting the Communication Cables

You can connect one NCB-E boiler with up to 15 Navien water
heaters, using the Ready-Link communication cables. Select the
NCB-E series combination boiler in the cascading system as the
master unit, and then connect the water heaters to it as slaves.
Before making any connections, ensure that the power is turned
off to all the units.
Connect the Ready-Link cables to the J6 port of the master unit
and to the J6 port of the slave water heaters (on the right side of
the front panel):
S R O/R
For NR/NP units, connect the Ready-Link cable to the
Note
CN9 port on the main PCB.
4.3 Configuring the Communication
Settings
After connecting the Ready-Link communication cables, restore
power to the combination boiler and turn on all water heaters
using the Power button.
4.3.1 Cascade Protocol Settings
Cascade protocol may be set for 2 different communication speeds
according to the type of water heater units installed in the system.
Refer to "Setting the Cascade Protocol" on page 62 and match
the communication settings accordingly.
Item
Use this setting when all the slave units are NPE water
NPE
heaters.
Use this setting when the slave units consist of NR/NP
NR/NP water heaters, or a combination of NPE and NR/NP
water heaters.
psi
Description
Installing a Cascading System 33