36
Unit 6
Unit 2
Unit 3
Unit 4
Unit 5
Unit 1
Cold water supply pipe
(1 1/4” - 5”)
Hot Water Return Line (3/4” - 1 1/4”)
Hot Water Supply Pipe (1 1/4” - 5”)
(Size for max. flow)
Expansion
Tank
Hot water supply points
When installing 2 pumps in parallel
Circulation pump 1
Circulation pump 2
Remote Controller
System Controller Unit
Pump Control Wires
(use external relays)
Set “Yes” for the question
“Start pump rotation?” in system settings.
(See SCU-401-12M Installation Manual)
*
Size the cold water supply piping to
allow for maximum flow rates
of the units.
B-1. Example of Recirculation with a Multi-System (Using external system controller)
This system will make hot water more quickly available to remote fi xtures.
The pump will circulate water through the loop until the entire loop is warm, and then the system
controller will turn off the pump until the loop cools down.
*
Siz
e the pump to pro
vide at least 8 L/min @ 3 m of head + piping losses through the system.
Chec
k the maintenance monitors on the unit to mak
e sure the pump is pro
viding adequate fl
o
w
.
•
Mak
e sure that the fl
o
w
r
ate is not g
reater than 1.2 m/sec.
(3/4”:
20 L/min, 1 1/4”:
50 L/min)
If the fl
o
w
is too lo
w
, the recirculation loop temper
ature will not be w
a
rm
enough, if the fl
o
w
is too
high, the lif
etime of the unit will be reduced.
*
If there are m
ultiple circulation loops
, tr
y to mak
e the fl
o
w
r
ate .3-5 L/min in each loop
.
*
Use copper or stainless w
ater piping f
or the entire system.
(Recirculation system)
