SQFlex data booklet

Parallel wiring
When wiring panels in parallel, results are the opposite of
series wiring: amperages add and voltage stays the same.
To wire panels in parallel, connect the positive terminal of
each panel to the positive terminal of the other panels and
negative terminal of each panel to the negative terminal of
the other panels.
1 2
3
4
TM062378
Solar panel wiring in parallel
Pos. Description
1 Panel #1
2 Panel #2
3 Panel #3
4 Panel #4
Panel voltage remains the same, so if the panels in fig.
Solar panel wiring in parallel produce 70 V each, then the
total output is 70 V.
Panel amperage adds in parallel, so if the panels in fig.
Solar panel wiring in parallel are rated at 1.43 A, then the
total current will is the following:
1.43 + 1.43 + 1.43 + 1.43 = 5.72 A
Panel wattage always adds, so if each panel is rated at
100W, the total wattage (Watts = Volts x Amps) output is the
following:
100 + 100 + 100 + 100 = 400 W
Series/parallel circuits
A series/parallel circuit is simply two or more series circuits
that are wired together in parallel.
1
32
65
4
TM062379
Solar panel wiring in series/parallel circuit
Pos. Description
1 Pair #1
2
Panel
#1
3
Panel
#2
4 Pair #2
5
Panel
#3
6
Panel
#4
In fig. above, two separate pairs of panels are wired in
series and each of these series pairs are wired together in
parallel.
To determine the total voltage and amp output of this array,
consider first each pair of panels wired in series. Think of
each pair as a single panel. Each panel has a rating of 70 V,
1.43 A and 100 W. Note that in series, voltage adds, while
amperage remains the same. Pair #1 provides 70 + 70 =
140 V and 1.43 A. Pair #2 provides the same.
Now add the two pairs in parallel. Remember in parallel,
voltage remains the same and amperage adds. Each pair
produces 140 V, so the total voltage is 140 V. Each pair
produces 1.43 A, so the total amperage is the following:
1.43 + 1.43 = 2.86 A. Watts always add, so 100 W x 4 = 400
W.
Cable sizing
Use the following formula:
L=
ΔP x q x V
mp
2
[ft]
Wp x 0.00162
where
L = Length of cable [ft]
ΔP = Power loss [%]
q = Cross section of submersible drop cable [in
2
]
V
mp
= Maximum power voltage [V]
Wp = Watt peak [Wp]
To calculate the exact losses, use the sizing tool at
Grundfos Product Center.
SQFlex
5
25
System sizing