MAX Power COMPACT - Manual (Page 15)

English Manual: Compact Retract 12/24V, Version 2 14/04/2005
4.5 BATTERY REQUIREMENTS
+ -
12 V
800 CCA
50 Ah
+ -
12 V
800 CCA
50 Ah
+
-
12 V
800 CCA
50 Ah
+
-
12 V
800 CCA
50 Ah
Power
Fuse
Manual
Battery
Isolator
Electric
Battery
Isolator
POSITIVE:
To Relay
Positive Bar
NEGATIVE:
To A1 Terminal
on Motor Terminal
Busbar
When choosing the type of batteries needed for your thruster’s battery bank, keep in mind that
it is the CCA (Cold Cranking Amps) capacity that is the most important and not the Ah (Amp-
hour) capacity. This is because thrusters draw high currents, but only for very short periods of
time (maximum 3 min.)
Max Power would recommend using Exide, Maxxima 900 type batteries, which have an 800CCA
and 50Ah capacity.
If the dedicated batteries are charged by the alternator, the reference of the charge must be
taken after the diode-splitting block (if in doubt, consult a marine electrician).
If the batteries or cables are inferior to those recommended, the Compact Retract will not reach
its potential thrust. The greater the batteries and cables size, the better the thrust.
Thruster performances are quoted with a minimum 22 volts at the motor terminal busbar for a
24 volts model or 11 for 12 volts models (thruster running, boat in water).
4.6 POWER CABLE SECTIONS ( BATTERIES TO RELAY )
According to the ISO 10133 standards: “The length and cross sectional area of conductors in
each circuit shall be such that the calculated voltage drop shall not exceed 10% of the nominal
battery voltage at any appliance if the circuit is switched on at full load”.
The cable lengths as given in the table below are the total length of the positive cable measured
from battery bank to thruster relay, then the cable from thruster relay to terminal D1 or D2 on
thrusters motor terminal busbar plus the negative return cable from terminal A1 on terminal
busbar to battery bank. Please refer to the diagram “ Compact Retract, 12/24: Power Cable
Connections ” in the back of this manual.
Compact Retract, 12V Compact Retract, 24V Cable Lengths
From battery to thruster (+) &
back (-)
mm² AWG mm² AWG
5 m (2 x 2.5m) 70 mm² 2/0 50 mm² 1
10 m (2 x 5.0m) 95 mm² 3/0 70 mm² 2/0
15 m (2 x 7.5m) 120 mm² 4/0 95 mm² 3/0
20 m (2 x 10m) 120 mm² 4/0 95 mm² 3/0
When choosing or calculating the cable size needed for your thruster installation, do not forget
to take into account the thermal rating of the conductor insulation which are directly related to
the ampacity (current carrying capacity) of the cable. Always try to use cables with the highest
thermal insulation rating available or at least 85° - 90°C.
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