Page 5
Uni Instructions
Wire size.
Use heavy duty wire for the battery, and make them
as short as possible. This also applies to the battery
linking wire on 24v systems. 4mm
2
2
wire is generally
adequate.
Use of wire that is too long (and/or too thin) will
cause loss of power and may also cause the
decoupling capacitor (see ‘features’ diagram above)
to heat up. Under extreme conditions the capacitor
can disintegrate. Heat will also shorten the operating
life of this capacitor. Once the capacitor fails the
current output will fall dramatically.
Motor wiring
This is not so critical as battery wiring: too long
and/or too thin wire will cause a loss of maximum
current, will get hot and will waste battery power but
will not damage the controller. However, wire which
is too thick will do no harm either so we recommend
the same wire for the motor as for the battery.
Battery wiring
Battery connections to the controller are shown in the
diagram, left. Use only good quality battery
connectors: a controller with regenerative braking
feeds current back into the battery during braking and
if a battery connector falls off when braking this
regenerated current can pump up the voltage on the
dud battery connection.
Power Connections
Controls
The only external control the UNI needs is a speed
pot, shown in the diagram, below left. There are other
controls that you may add if you wish.
The Uni turns itself off automatically when you turn
the speed to zero, so you can fit an on/off switch in
series with the red wire as shown in the diagram
below, right. Opening this will remove the voltage
from the pot, so the controller will run down to zero
sped and switch off.
With the pot at zero, the controller draws only a very
small current: (24v version, about 1.8 mA and the
12v version about 5,6mA)
The two diagrams below also show the wiring to the
connector (which is internal to the controller) so if
you have the cased version - ignore the connector.
If you aren’t using the yellow wire, make sure it is
arranged so that it cannot touch anything: it carries
the full battery voltage. It is also possible to use these
four wires to connect a battery condition meter.
That’s really all you need to know to get the Uni
working!
Pot fault detection
This feature is not normally engaged: for it to operate
you must fit a resistor as shown in the third diagram.
Use 3K3 with a 10K pot and re-adjust the gain
control. Typically it is enabled to prevent the
controller going to full speed in the event of a broken
wire to the pot.
1
1
Max
Min
1
Max
Min
Max
Min
A
A
B
B
C
C
D
D
Green - min
Green - min
Red - max
Red - max
Blue - wiper
Blue - wiper
Green - min
Red - max
Blue - wiper
