Honeywell EN2H-0221GE51 R0808 service manual Prerequisite, Heat generator solid-fuel cycle disable

SDC / DHC Hydraulic Components

Solid-fuel boiler If the temperature in the solid fuel boiler rises above the set maximum temperature maximum temperature limit, the solid-fuel loading pump is forced

limit to switch on. The excess heat is then dissipated into the preselected circuits (see "Buffer Tank" menu). This forced dissipation will be cancelled and the temperature differential control enabled when the solid-fuel boiler temperature undershoots the maximum limit by more than 10 K.

Solid-fuel boiler buffer tank switch-on differential (switching differential ON)

Solid-fuel boiler buffer tank switch-off differential (switching differential OFF)

Heat generator cycle disable

Anti-blocking function

If the temperature in the solid-fuel boiler rises above the current temperature in the buffer tank by at least the set amount, the solid-fuel loading pump is switched on and the buffer tank is loaded.

Prerequisite:

The temperature of the solid-fuel boiler is at least 10 K over the minimum temperature limit.

The min. set value is 3 K above the switch-off differential.

If the differential between the solid-fuel boiler and buffer tank temperatures is less than the set amount, the solid-fuel loading pump is switched off and loading is interrupted. The max. set value is constantly 3 K below the selected activation difference in order to prevent rear discharging of the buffer tank.

Heat generator solid-fuel cycle disable

The solid-fuel cycle disable serves to prevent frequent switching between loading through the solid-fuel boiler and loading through a conventional oil/gas heat generator.

After the solid-fuel loading pump has been switched off, the set time must pass before loading of the buffer tank is continued through the conventional heat generator.

This is an automatic function of the controller. If the solar loading pump was switched off longer than 24 hours, it is operated for approx. 20 seconds to prevent blocking via corrosion.

7.3.7Tank loading switch-over

In systems that have both an external hot-water tank and a buffer tank, a diverter valve can be used to switch between loading the hot-water tank and loading the buffer tank from solar power system. This allows economical and effective use of solar power

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