Product Overview

System 450™ Series Modular Controls Product Bulletin 13
System 450 Differential Control
Figure 15 shows a System 450 solar water heating
application that uses the Differential Control feature to
enable a solar panel circulating pump whenever the
temperature at the solar panel exceeds the
temperature in the solar water storage tank by a
differential of 10 F° (5.6 C°).
The space heating circulating pump is enabled
whenever the solar water storage tank temperature
reaches 75°F (23.9°C) at Sn2 and the controlled space
is calling for heat at Sn3.
Figure 15: System 450 Solar Water Heating Application Using Differential Control
FIG:sys450_solar_heat_app_example
L1
L2
Sn-1
Sn-2
Sn-3
Active/Passive Sensor Jumpers
(All jumpers set in passive position.)
Sn3 - Controlled Space
Temperature Sensor
Sn2 - Storage Tank
Temperature Sensor
Sn1 - Solar Panel
Temperature Sensor
Solar Panel
Circulating Pump
Space Heating
Circulating Pump