Intelligent Technologies QCPort System Install Manual
November 2005
MN05001002E
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www.eatonelectrical.com
Page
24
Example 3 Middle Connected Power Supply
2. Sum up the currents per section
Section 1 (QCPort Interconnect) = 0.2 + 0.3 + 0.1 = 0.6 A (OK)
Section 2 (Backplane) = 1.0 + 2.0 = 3.0 A (OK)
Find the voltages for each device using the equation for Long Run.
SUM {[(L
n
x (0.105)) + (N
t
x (0.005))] x I
n
} <= 4.65V
Device 1
[(
9
x (0.105)) +
(3
x (0.005))] x
0.2
=
0.19V
Device 2
[(
6
x (0.105))+
(2
x (0.005))] x
0.3
=
0.19V
Device 3
[(
3
x (0.105)) +
(1
x (0.005))] x
0.1
=
0.03V
Device 4
[(
0
x (0.105)) +
(1
x (0.005))] x
1.0
=
0.00V
Device 5
[(
0
x (0.105)) +
(2
x (0.005))] x
2.0
=
0.02V
Add each Devices voltage together to find the total voltage per section.
Section 1 – 0.19+0.19+0.03 =
0.41V
(OK)
Section 2 – 0.00+0.02 =
0.02V
(OK)
Results
Since the total voltage does not exceed 4.65V in either section, the system will operate
properly.
T
D3
.1A
PS
D4
1 A
D2
.3 A
D5
2 A
3 foot
3 foot
3 foot
0 foot
T
D1
.2 A
0 foot
Section 1
Section 2
3 foot
