lp-672 Rev. 000 Rel. 002 Date 10.3.18
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Figure 20 - This chart represents the internal recirculation pump performance curve taking into account valves and heat exchanger pressure losses.
F. Circulator Sizing
Figure 21 - This chart represents heat exchanger pressure drop through the heat exchanger and internal valves.
NOTE:
When using external recirculation mode with the built-in pump, observe the following maximum recirculation pipe lengths including
fittings:
•
½” Copper Pipe- 200 ft (60 m) of equivalent pipe length
•
¾” Copper Pipe- 500 ft (167 m) of equivalent pipe length.
Lengths in excess of these limits will require an external recirculation pump. See pressure drop curve to size pump accordingly.
Use Function 16:so in the Installer Menu to widen the Delta-T to avoid short cycling if recirculation line is not insulated.
