Setting Proportional Factor - Blue I HydroGuard HG-302 Manual De Uso

8.2

Setting Proportional Factor

Proportional control of chemical dosing requires configuration according to various factors. The primary
factors are the ratio between the pool size and the rate the chemical dosing systems can feed chemicals,
and the delay time between when the chemical level changes and when it is sensed by the controller.
In large pools, changes in chemical levels occur slowly. The dosing systems must feed large amounts of
chemicals for a long period of time in order for a change to be noticed. The chemicals also disperse slowly in
larger pools. Smaller pools, on the other hand, react much more quickly.
The length of time between the change and when the controller identifies the change also affects
proportional control. The controller can only identify water chemical levels after they have been distributed
throughout the pool, and have returned to the pump room for analysis by the automatic controller. This may
be a long time after the chemicals were released into the pool. The controller, therefore, recognises the
chemical levels from dosing settings in the past. The dosing systems continue feeding chemicals during this
delay, causing chemical levels to pass the set point, resulting in fluctuations.
Set Point
Chemical Level
Figure 30: Feedback Delay Causes Chemical Levels to Pass the Set Point
To prevent these fluctuations, the controller must reduce chemical dosing rates as it senses that chemical
levels are approaching the set point, taking the delay into account. The controller should also not
overcompensate for the delay, which would cause chemical levels to not reach the set point at all.
The proportional factor for chlorine and pH proportional control can be set on a scale of zero point one (0.1)
to fifty (50) for total chlorine and zero point one (0.1) to one -hundred (100) for pH. A high proportional factor
means that chemical levels rise and fall unimpeded until they cross the set point, as displayed below.
Figure 31: Proportional Factor = 50
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