Atag i15R, Техническое руководство

Страница: 31 / 64

Gradient speed CH
The gradient allows the boiler to increase the CH water temperature with a pre-set (parameter 2.0.6) number of degrees per
minute. The number of degrees can be set between 1 and 15 per minute (factory set to 5 (NG) or 0 (LPG)).
The Gradient control is a calculated increase of the T-Set value. When the flow temperature is 5 degrees higher than the T-set
temperature, the boiler will switch off. So, if you set the max flow temperature to 80 the boiler will switch off at 85.
Scenario:
Boiler set with parameter (2.0.6) with a gradient speed CH of 5 = 5°C per minute increase. CH T-max 80°C
If the boiler starts with 35°C flow temperature the boiler will calculate a T-set temperature using the gradient line. This will
look to raise the flow temperature to 40°C after 1 minute and look to raise it a further 5°C the minute after, as an on ongoing
gradient line, which is recalculated as the boiler is working. If the boiler goes past this gradient line T-set temperature by more
than 5°C the boiler will switch off. The boiler 5 minute anti-cycle feature will operate. When the boiler comes back on again it
will start the process off again with the new flow temperature.
A boiler / system that cannot get rid of this heat effectively will see a rapid increase in the flow temperature (more than the 5°C
per minute it has been set up to do). The flow temperature will quickly go over the calculated T-set temperature (gradient) by
the 5°C and would switch off.
The following gradient speed settings are recommended for each type of heating system:
1 – 2 underfloor heating
4 – 5 Radiator convectors
7 – 8 Indirect heated air heater
Setting the gradient parameter to 2.0.6 = 0
If you set this to 0, you switch off the gradient control and the T-set is the temperature set with the CH button (normally 80°C).
In this case there is no limit to the number of degrees temperature increase per minute and the boiler will try to reach its set
point as quickly as possible.
So, the boiler will go to full load and try to reach the set water temperature set under the CH button.
There is no restriction to the number of degrees temperature increase per minute (The brake is off). The boiler will then
modulate, because the delta T is reached. The boiler will try and maintain the delta T across the heat exchanger around 20°C.
Select manual mode activation to enable manual testing of the pump, fan, diverter valve or external pump.
2.6. General Name Description Unit Range Default
2.0.6 T-Gradient Gradient Function °C/min 0 - 15
5 (NG)
0 (LPG)
31