32
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 Unit
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 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.
*
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
fl o
w.
•
Make sure that the
fl
ow rate is not greater than 4 ft./sec.
(3/4”: 5 GPM, 1 1/4”: 13 GPM)
If the
fl
ow is too low
, the recirculation loop temperature will not be warm enough, if the
fl
ow is too
high, the lifetime of the unit will be reduced.
*
If there are multiple circulation loops, try to make the
fl
ow rate .75-1.25 GPM in each loop.
*
Use copper or stainless water piping for the entire system.
(Recirculation system)
