Rev 6.3.0 12.09.16
PL Reference Manual
24
SET/MODE/BSET Selection Summary:
Selection
Function
0
B- input used for battery
negative voltage sensing
1
2nd battery voltage sensing
2
external input VEXT, used by
event controller
7
Diversion Control
The PL supports either series control, diversion
control, or both at the same time. In a hybrid
system, the main solar component is controlled
by the SOL- input and the other charge
component (wind, hydro, etc) is managed by
diversion control via the LOAD- or ‘G’ terminal
switching in a ‘dump load’, either directly or with
a relay. These functions are configured in the
LSET and GSET screens. (see section 7.5.
1
and
7.5.2)
Regulating Wind / Hydro:
Diversion control is appropriate for wind
generators or microhydro systems, which
require a constant load on the charging source
so the generator doesn’t overspeed and damage
itself. In this case the charging source must
remain connected to the battery at all times.
Diversion control refers to the technique of
controlling the battery voltage by drawing energy
from the system with a ‘dump load’, rather
than disconnecting the charge source as “series
control” does on the solar input.
To regulate a wind or microhydro installation
with diversion control, a dedicated dump load
must be available for the PL to switch across the
battery. The dump load must be larger (at the
range of expected regulation voltages) than the
maximum charge current available from your
generator. The voltage to use for calculating the
dump load value is the FLOAT voltage.
Example:
and conservative power requirements for the
dump load are:
Note:
Remember that the Dump Load value will
need to be recalculated if you change either the
FLOAT voltage or the EMAX Equalise voltage.
The function of the dump load is to ‘soak up’
energy coming in which the battery cannot store
in order to maintain the desired battery voltage.
The input labelled B- (part of the green terminal
block under the cover) is intended as a sense
input for the battery negative voltage. This can
be connected directly to the battery negative
terminal and will read the true battery negative
voltage. This is important if there is significant
voltage drop along the wiring (including the
fuse) between the BAT- terminal on the PL and
the real battery negative. (If there is significant
voltage drop on the positive side, then take
the BAT+ terminal on the PL20/40 directly to
the battery positive via a fuse. The fuse need
only be rated for the PL current, say 200mA.
Take the charge current from the array to the
battery separately via it’s own fuse. The idea is
that the array current is not passing through the
same wire as the PL positive supply current).
Alternatively on the PL60/80, connect the
sense terminal (part of the green
terminal block under the cover) directly to the
battery positive terminal.
If the B- input is not being used for this, then it
can be used for sensing the voltage on a second
battery being charged or for providing a voltage
input for the event controller (Push button or
VEXT).
‘Push Button’ Switch Input
If you wish to use the B- (sense) input as a switch
event input, you must wire a switch or other
trigger between the B- (sense) terminal (green
terminal block) and the Bat- terminal and set
BSET = 2.
7.5.3 BSET: Configuring B- Sense Input
=
Dump
Load
(ohms)
Nominal Voltage (V)
Max generator current (A)
=
x
2
Dump
Load
Power
max (w)
Dump
Load
(ohms)
EMAX Equalisation
Voltage (V)
Dump Load (ohms)
)
(
X
Margin
e.g. Margin=1.2 for 20%
e.g. Nominal=12V,24V,48V
