Installation Manual

Chapter 8 N40475
Page 40
Power connections
1. Marine junction box.
2. Battery reverse isolator.
3. Batteries
4. Minus battery bus bar.
Cable
length*
4 Stations 8 Stations
12 volt 24 volt 12 volt 24 volt
5ft.(1.52m) 10 AWG 12AWG 6AWG 10 AWG
10ft
(3.05m)
10 AWG 12 AWG 6 AWG 10 AWG
15ft
(4.57m)
8 AWG 10 AWG 4 AWG 8 AWG
25ft
(7.62m)
6 AWG 8 AWG 2 AWG 6 AWG
30ft
(9.14m)
4 AWG 8 AWG 1 AWG 4 AWG
*Refer to ABYC rules E-11 for AC & DC electrical systems
on boats for more details.
Note: Perkins recommends installing two +battery
and two -battery cables from the reverse isolator to
the MJB and from the reverse isolator to the batteries.
Current requirements 12 or 24 vdc
system
The typical current draw for the MSCS with a twin
engine installation with 4 control stations is 30 amps .
The current draw for a twin engine installation with 8
control stations is 62 amps .
ECM port or starboard interface
connectors
The MJB provides two interface connectors, one for
the port engine and one for the starboard engine,
which connect to the J61 customer connector. The
connections are to interface with the ECM customer
connector and provide battery power, switched inputs
and data link signals to and from the ECM. The
pin out is the same for both the port and starboard
connectors .
Grounding the battery negative
It is recommended that the battery negative busbar
should be grounded as close as possible to the
battery, by a substantial connection to the bonding
system within the boat. This will reduce the likelihood
of interference between items of electrical and
electronic equipment tted to the boat.
Figure 23