2

2.6.2

Working principle of the appliance

gis

 

Fluid temperature

The heat exchanger of the solar heating system may be filled with glycol. If the temperature of the heating fluid is too high, a signal is sent to the controller of the solar collector and the pump of the solar collector is switched off. This signal is passed to the controller by temperature sensor S1.

At present, no heating fluids other than glycol are supported. The heating fluid type is set (12.9.2 "Setting the heating fluid type in the solar heating system") during installation.

Temperature protection for solar heating system

Protection

Description

 

 

Maximum temperature S1, if solar

The pump of the solar heating system

heating system is filled with

switches off when the temperature of the

glycol:

heating fluid at S1 exceeds the maximum

- S1 > 130°C

value. The solar heating system enters

 

error mode. The error is also visible on the

 

display of the SGE appliance

2.7Safety of the solar heating system

2.7.1Expansion vessel

The solar heating system must be equipped with an expansion vessel (16). An expansion vessel serves to limit pressure variations in the system. The expansion vessel in the solar heating system can withstand a maximum pressure of 6 bar. The supply pressure to the expansion vessel depends on the static head of the system.

Besides the expansion vessel, the system is protected from overpressure by an expansion valve (2.7.2 "Expansion valve").

2.7.2Expansion valve

The solar heating system is equipped with an expansion valve (23). The expansion valve monitors the pressure in the solar heating system. If the pressure is excessive (> 6 bar), then the valve will open. The hot water can now flow out of the installation. The valve remains open until the unsafe situation has passed, i.e. until the pressure has fallen back below 6 bar.

Note

Because the installation is always under pressure and is not automatically filled, the system will again need to be replenished (5 "Filling").

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Instruction manual SGE

Page 18
Image 18
A.O. Smith SGE service manual Fluid temperature, Safety of the solar heating system Expansion vessel, Expansion valve