Hamworthy PUREWELL VariHeat he, Инструкция по установке, пусконаладке и обслуживанию

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HAMWORTHY HEATING LTD
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PUREWELL VariHeat he 500001155/F
8.5.7 Special Boiler Functions
8.5.7.1 Anti-cycling
This function is used to limit the switching ON of the boiler in the case of poor heating system design or during
instances of low demand. The anti-cycling function can block a heat demand for a specific time by setting the rele-
vant parameter and is enabled as soon as the block is instigated due to excessive flow temperature. When en-
abled, any further demands for heat will be blocked and displayed on the screen.
When the heat demand is blocked due to excessive flow temperature and as a result, the flow temperature drops
too quickly during the anti-cycle time, the block can be released before the pre-set time if the return temperature
has dropped by at least the offset based on the return temperature at the start of the block.
8.5.7.2 Control of flow temperature gradient.
The flow temperature gradient is activated by the following heat demand:
•
BMS based on temperature
•
Remote On/Off
After switching ON the boiler, if the flow temperature rises too fast (gradient of the flow temperature too high), the
control will set the fan speed to the minimum firing rate. Normally the PI - control should cope with this problem,
but this function will prevent overshoot of the flow temperature when almost no power is required. The maximum
gradient allowable will vary with the actual water temperature reading such that a lower maximum is allowed as
the flow temperature set point is approached - see figure 8.5.7.2 .
Below the Hysteresis line, the fan speed control is based on the PI– regulation. Above the Hysteresis line, the fan
speed is set to its minimum.
The gradient function is determined by points A & B, by setting the relevant parameters.
Figure 8.5.4 - CH heat curve
Figure 8.5.7.2 - Control of flow temperature gradient