Connecting The Communication Cables - Navien NFB-175H Installation Manual

8.1.1 Piping Sizes and Considerations
When plumbing 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-175H
Flow Rate (GPM)
Qty
@ 20°F ΔT
2 32.2
3 48.3
4 64.4
5 80.5
6 96.6
7 112.7
8 128.8
9 144.9
10 161
11 177.1
12 193.2
13 209.3
14 225.4
15 241.5
16 257.6
NFB-200H
Flow Rate (GPM)
Qty
@ 20°F ΔT
2 36.6
3 54.9
4 73.2
5 91.5
6 109.8
7 128.1
8 146.4
9 164.7
10 183
11 201.3
12 219.6
13 237.9
14 256.2
15 274.5
16 292.8
76 Installing a Cascade System
Recommended
Boiler Pipe Sizes
(2-4 ft/s)
2"
2-1/2"
3"
3"
3-1/2"
3-1/2"
4"
4"
4"
5"
5"
5"
5"
5"
6"
Recommended
Boiler Pipe Sizes
(2-4 ft/s)
2"
2-1/2"
3"
3-1/2"
3-1/2"
4"
4"
5"
5"
5"
5"
5"
6"
6"
6"
8.2 Connecting the
Communication Cables
Up to 16 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:
SUPPLY RETURN OUTDOOR DHW TANK
When installing the cascade system,
Note
refer to "8.1 Connecting Water Supplies".
Also, connect zone pumps to the zone
controller. Do not connect zone pumps
to the main or sub units.
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 (
Refer to "11.6.4 Configuring a Cascade System" to
configure the communication settings.
NC
NC
NC
COM
NC
NC
COM
NC
NC
COM
NC
NC
COM
NC
NC
COM
NC
LWCO
COM
AC24VL
LWCO
AC24VN
AC24VL
AC24VN
C
W
R
C
W
R
C
W
R
C
W
R
).