Burkert 8681 - Design Aid

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120VAC - Design
Feedback signal output: S4 out is directly connected to S4in
Input / proximity switches (external initiator: S4 in):
  Powersupply:      voltagepresentatcontrolheadUNominal=120VAC,50/60Hz
Design: DC 2 and 3-wire,
Normally open contact, L-switching
Inputcurrent1-signal:     ISensor<2mA
Inputs valve actuation (Y1 - Y3):
Signal level - active: U > 60 V AC
  Signallevel-inactive:     U<20VAC
Impedance: > 40 kOhm
11.3 Design aid
Power consumption of the electronics:
P
El
=1.2VA or I
El
=10mA at 120 V AC
Power consumption of a valve during activation (200 ms):
P
Valve-ON
=1.7VA or I
Valve-ON
=14mA at 120 V AC
Power consumption of a valve after reduction:
P
Valve
=1.4VA or I
Valve
=12mA at 120 V AC
Power consumption of an optical position report:
P
LED
=1.6VA or I
LED
=13mA at 120 V AC
Also, if several control head valves were to be opened simultaneously, the switch signal will be sent
staggered to the valves. Only one valve 1.7 VA will ever be recorded.
Calculation examples:
Example 1:
3valvesareactivatedsimultaneously,onepositionisreported(statusfor200ms):
P
Total
= P
El
+ 1 x P
Valve-ON
+ 2 x P
Valve
+ 1 x P
LED
7.3VA= 1.2 VA + 1 x 1.7 VA + 2 x 1.4 VA + 1 x 1.6 VA
or
I
Total
= I
El
+ 1 x I
Valve-ON
+ 2 x I
Valve
+ 1 x I
LED
61 mA = 10 mA + 1 x 14 mA + 2 x 12 mA + 1 x 13 mA
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Control Head Type 8681