LG Electronics 120S Power consumption block diagram of PLC systems, Power Input Supply, Part

Chapter 9 Installation and Wiring

4) Power consumption block diagram of PLC systems

Main Unit

	I5V		5VDC line
power					Input
supply
						special
part		CPU part	output part	input part
			(transistor)			module

AC power	Output Current.	Input Current
Supply
	(IOUT)×Vdrop	(IIN)×Vdrop
	I24V

Output part

(Transistor)

Output Current.

(IOUT)×Vdrop

Expansion module

Input part

Input Current

(IIN)×Vdrop

		Output		Input
	24VDC line	Current		Current
		(IOUT)	Load	(IOUT)
External
24VDC
power
Supply

Output		Input
Current		Current
(IOUT)		(IOUT)
	Load

5)Power consumption of each part

(1)Power consumption of a power supply part

Approximately 65% of the power supply module current is converted into power 35% of that 65% dissipated as heat, i.e., 3.5/6.5 of the output power is actually used.

• Wpw = 3.5 / 6.5 {(I5V x 5) + (I24V x 24)} (W)

where, l5v: 5VDC circuit current consumption of each part

l24v: 24VDC circuit average current consumption of output part (with points simultaneously switched ON). Not for 24VDC power supplied from external or power supply part that has no 24VDC output.

(2) Total 5VDC power consumption

The total power consumption of all modules is the power of the 5VDC output circuit of the power supply part.

•W5V = I5V × 5 (W)

(3)Average DC24V power consumption (with points simultaneously switched ON)

The total power consumption of all modules is the average power of the DC24V output circuit of the power supply part.

•W24V = I24V × 24 (W)

(4)Average power consumption by voltage drop of output part (with points simultaneously switched ON)

•Wout = Iout × Vdrop × output points × the rate of points switched on simultaneously (W)

Iout : output current (actual operating current) (A)

Vdrop : voltage dropped across each output load (V)

(5)Average power consumption of input parts (with points simultaneously ON)

•Win = lin ×E × input points × the rate of points switched on simultaneously (W) Iin : input current (effective value for AC) (A)

E : input voltage (actual operating voltage) (V)

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