71
Installing a Cascade System
8.2 Connecting the Communication Cables
Up to 32 boilers can be connected with Navien Ready-Link
communication cables. Select one of the boilers in the cascade
system as the main boiler, and then connect the other boilers to
it as sub boilers. Before making any connections, ensure that the
power is turned off to all boilers.
Connect the Ready-Link cables to the CNK1 terminal strip on the
PCB:
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8.2.1 Configuring the Communication Settings
After connecting the Ready-Link communication cables, restore
power to the boiler and turn on all boilers using the Power button.
To configure the communication settings, refer to “11.6.4
Configuring a Cascade System” on page 103.
8.1.1 Piping Sizes and Considerations
When configuring a cascade system, consider the following pipe
diameters and flow rates. Note that flow rates above 4 ft/s may
cause pipe erosion or velocity noise. These specifications may vary
depending on installation conditions.
NFB-301C
Qty
Flow Rate (GPM)
@ 20 °F ΔT
Recommended
Boiler Pipe Sizes (2-4 ft/s)
2
58
2-1⁄2"
3
87
3”
4
116
4”
5
145
4”
6
174
5”
7
203
5”
8
232
5”
9
261
5”
10
290
6”
11
319
6”
12
348
6”
13
377
6”
14
406
6”
15
435
7”
16
464
7”
NFB-399C
Qty
Flow Rate (GPM)
@ 20 °F ΔT
Recommended
Boiler Pipe Sizes (2-4 ft/s)
2
76
3”
3
114
3-1⁄2”
4
152
4”
5
190
5”
6
228
5”
7
266
5”
8
304
6”
9
342
6”
10
380
6”
11
418
7”
12
456
7”
13
494
7”
14
532
8”
15
570
8”
16
608
8”
Summary of Contents for NHB Series
Page 120: ...120 Appendixes 12 6 Component Assembly Diagrams and Part Lists 12 6 1 Case Assembly NFB 301C...
Page 122: ...122 Appendixes 12 6 2 Case Assembly NFB 399C...
Page 124: ...124 Appendixes 12 6 3 Heat Exchanger and Waterway Assembly NFB 301C...
Page 126: ...126 Appendixes 12 6 4 Heat Exchanger and Waterway Assembly NFB 399C...
Page 128: ...128 Appendixes 12 6 5 Combustion Parts Assembly NFB 301C...
Page 131: ...131 Appendixes 12 6 6 Combustion Parts Assembly NFB 399C...
Page 134: ...Memo...
