9 LOADING AND INSTALLATION

MELSEC-Q

(6)Power consumption of the power supply section of the intelligent function module

WS = I5V 5 + I24V 24 + I100V 100 (W)

The total of the power consumption values calculated for each block becomes the power consumption of the overall sequencer system.

W = WPW + W5V + W24V + WOUT + WIN + WS (W)

From this overall power consumption (W), calculate the heating value and a rise in ambient temperature inside the board.

The outline of the calculation formula for a rise in ambient temperature inside the board is shown below.

W

T = UA (°C)

W: Power consumption of overall sequencer system (value obtained above) A : Surface area inside the board

U : When the ambient temperature inside the board is uniformed by a fan......... 6 When air inside the board is not circulated.............................................. 4

POINT

When a rise in ambient temperature inside the board exceeds the specified limit, it is recommended that you install a heat exchanger in the board to lower the ambient temperature inside the board.

If a normal ventilating fan is used, dust will be sucked into the PLC together with the external air, and it may affect the performance of the PLC.

(7)Example of calculation of average power consumption

(a) System configuration

Q61P-A1

Q02HCPU

QX40

QX40

QY10

QJ71LP21-25

Vacant

 

 

 

 

 

 

 

Q35B

(b) 5 VDC current consumption of each module

Q02HCPU

: 0.64 (A)

QX40

: 0.05 (A)

QY10

: 0.43 (A)

QJ71LP21-25

: 0.55 (A)

Q35B

: 0.074 (A)

(c)Power consumption of power supply module

WPW = 3/7(0.64+0.05+0.05+0.43+0.55+0.074)5) = 3.84 (W)

(d)Power consumption of a total of 5 VDC logic section of each module W5V = (0.64+0.05+0.05+0.43+0.55+0.074)5) = 8.97 (W)

(e)A total of 24 VDC average power consumption of the output module W24V = 0 (W)

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