38
Unit 12
Unit
2
Unit
3
Unit 10
Unit 11
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 Uni
t
Pump Control Wires
(for pumps > 85 W, use an external relay)
Set “Yes” for the question “Start pump rotation?” in system settings. (See SCU-301-12M 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 fixtures.
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.
*
Size the pump to provide at least 2 GPM @ 10 feet of head + piping losses through the system.
Check
the
maintenance
monitors
on
the
unit
to
make
sure
the
pump
is
providing
adequate
flow
.
•
Make
sure
that
the
flow
rate
is
not
greater
than
4
ft./sec.
(3/4”: 5 GPM, 1 1/4”: 13 GPM)
If
the
flow
is
too
low
, the
recirculation
loop
temperature
will
not
be
warm
enough,
if
the
flow
is
too
high, the lifetime of the unit will be reduced.
*
If
there
are
multiple
circulation
loops,
try
to
make
the
flow
rate
.75-1.25
GPM
in
each
loop.
*
Use copper or stainless water piping for the entire system.
(Recirculation system)
