3
General Information:
USDT 2004, program mode “0”, is suitable for Closed and Open Loop systems.
Closed Loop Solar Heating Systems are the preferred option for extremely cold
areas and areas with questionable water quality. The following arrangement
shows an application example in a closed loop system.
1. Collector
7. Check Valve
13. Pressure Gauge
2. Collector Sensor
8. Hose Bibs for Filling and Flushing
14. Collector Supply
3. Manual Air Valve
9. Expansion Tank
15. Heat Exchange Coil
4. Hot Water to Taps
10. Air Purge and Air Vent
16. Solar Hot Water Tank
5. Tempering Valve
11. Circulating Pump with flanges or couplings
17. Immersion Heater
6. Collector Return
12. Pressure Relief Valve
18. USDT 2001 Controller
Operation:
USDT 2004 Controller (18)
will switch on the pump (11) when the temperature
at the collector sensor (
T
1
) T
C
is higher than the return temperature (
T
2
) T
R
by at
least the pre-selected amount ?T. The
pump
circulates a heat transfer fluid
around the loop.
Heat
from the collector is transferred to the storage tank through
the heat exchange coil. With the pump running, if DELTA T is less than preset
value, the pump will switch off. When a preset collector temperature is reached at
T
MAX
, the controller switches off the pump. The
check valve
(non-return valve)
prevents heat from the tank rising towards the collector, should the tank be
warmer (e.g. at night). Please refer to the operation section of manual.
