Etatron eSelect-CD1, Инструкция по эксплуатации и техническому обслуживанию

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16 ENGLISH
DELAY
• Delay time blocks relay outputs (max 999 sec. programmable) to ensure that the outputs are active only when the sensors
measurements are stable thus allowing the best results in terms of chemical balance.
TIMED PULSES MODE (PWM) PULSES WITH MODULATION TIME/PAUSE
•
Timed Pulses also known as PWM “pulses with modulation” time/pause allows proportional mode on each ON-OFF set-point activating
corresponding pulses with Start/Stop time cycle variation according to measured value in respect to set-point.
Window Width (example range 2000 μS): pulses are timed ON and OFF according to the distance from selected set-point,
programmable, example: if selected set point is 700 μS EC and measured value is 600 μS, PWM mode will start after reaching 650 μS
with Time/Pause pulses and decreasing the active time while reaching set point value.
Cycle Time: PWM mode cycle 60 seconds (programmable): example set point 700 μS = active time 60 sec - pause time = 0 sec.; 675
ppm active time= 30 sec / pause time 30 sec.....and decreasing active time accordingly while reaching set point value. Cycle time
depends on many variables such as: distance from injection point to treating system, how fast or slow set point must react, chemical
concentration, etc....
Active Time MIN programmable: it sets the minimum time in which PWM is active; it overrules selected settings. Times Pulses function is
adjusted via 3 functions following the formula:
Active Time according to selected formula = (measured value – set point) / window width * cycle time If the result of the formula is < the
selected Active Time Min, the latter with overrule the first, example range 2000 μS: measured 600 μS -set point 700 μS / Window Width
0.50 *Cycle time 60 sec=active time 4 sec.
In case user has selected Active time min 5 sec., this will be minimum time of PWM and not 4 sec.
BENEFITS: a simile-proportional function more accurate then ON-OFF mode using simple equipment such as Constant dosing pumps and
peristaltic dispensers.
DISAVANTAGES: not as accurate as mA mode, user needs an accurate selection of dosing unit flow rate.
PROPORTIONAL ANALOG CURRENT OUTPUT 4÷20 mA
•
4÷20mA1 and mA2 programmable proportional mode: at 4 mA corresponds selected set-point, at 20 mA corresponds the max
measured distance from selected set point. The active time on the mA outputs is calculated according to the following relation: 0 sec:4
mA / 1 sec:20mA. Analog mA outputs connections are galvanic separated. Controller allows choosing between AUX (driving data logger
or data recorder or other equipment) and Dosing set point (driving dosing pumps) or all equipment suitable to work with mA signal).
BENEFITS: best results because pulses are extremely accurate in relation to measured levels.
DISAVANTAGES: user needs a specific dosing pump for such operational mode.
OVERDOSING TIME
•
Over dosing time-out alarm allows to select a period of time in which set point must be reached. If during this time set point is not
reached, controller will block outputs operations including mA outputs (dosing pump), Alarm is ON shown on display and will activate a
signalling device connected to alarm relay.
BENEFITS: to prevent excess of chemical addition.
START-UP DELAY
•
Start-up Delay time “freezes” the relay outputs when switching ON the unit thus allowing sensors to polarize ensuring correct
measurements (programmable).
FLOW SENSOR “PROXIMITY SWITCH” FUNCTION
• Flow Sensor: in case, no water is running through the sensor cell holder (and eventually into the systems), flow sensor (proximity switch)
will deactivate all outputs ensuring that no extra chemical is added.
TEMPERATURE
• Manual temperature compensation. 0÷100°C. Selecting TEMP.PROBE (latter temperature sensor) compensates temperature/electrode
measurements, always giving the exact value against the current temperature.