START | Starts pump at |
ALARM | Enables/Disables protection functions |
BTU | Energy calculation and setting |
S ensor Designation – USDT 2004 accepts two different sensor types or a reference value . User can program a constant reference temperature instead of a sensor output. The
white wire, should be used in a conditioned environment and will not be permanently damaged up to 360 oF.
Selection:
S1 Sensor 1 (collector outlet) selection
S2 Sensor 2 (collector inlet) selection
S3 Sensor 3 (tank) selection
Designation:
PT PT 1000 sensor (1000 O at 0 oC, not available in US market)
KTY Thermistor sensor (2000 O at 25 o C)
250250 oF reference temperature
- 4 - 4 oF reference temperature
Sensor wires can receive electromagnetic pulses, which can result in a wrong temperature reading. The USDT 2004 reads sensor values every 50 ms. It can bundle several readings and process their average.
AV 1 Sensor 1 average
AV 2 Sensor 2 average
AV 3 Sensor 3 average
The numbers of samples can be programmed from 4 to 20. The impedance characteristics of sensors temperature dependencies are represented in the following table:
T | 0 | 10 | 20 | 25 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100°C |
R(KTY) | 1630 | 1772 | 1922 | 2000 | 2080 | 2245 | 2417 | 2597 | 2785 | 2980 | 3182 | 3392 Ω |
Frost and overheating protections - Pump operation can be manipulated by the user in both collector stagnation and frost conditions. The
SGUARD, domain.
Overheating protection – The Circulation pump may not be powerful enough to circulate the heat transfer fluid in the solar loop with air pockets. User can program the pump to stop at a desired maximum collector temperature, shown by ? symbol, to protect the pump. The USDT 2004 will take over the normal operation after the temperature decreases to an acceptable working temperature, shown as =. This feature is disabled at 299 oF set point.
Frost Protection – Frost protection in the
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