Mars Air Systems L-2254 - Manual (Page 8)

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English L-2254 Installation
Electrical Connections, Grounding
and Bonding
All a/c units have a terminal strip mounted inside the
electric box. The terminal strip is labeled for proper
connections of the electrical supply, ground wires and
pump circuits. A wiring diagram is provided in the
electrical box and in this manual. The wiring diagram in
the electrical box supersedes the one in this manual and
ABYC standards. The correct size circuit breaker should
be used to protect the system as specified on the a/c
unit’s data plate label. A minimum of 12 AWG boat cable
should be used to supply power to the a/c unit and the
seawater pump. All connections shall be made with ring
or captive fork terminals. Turn off a/c power supply
circuit breaker before opening electric box. See
Figures 9 and 10.
Each a/c unit installed requires its own dedicated circuit
breaker. If there is only one a/c unit installed, the
seawater pump does not require a circuit breaker; the
wiring from the seawater pump is connected to the
terminal strip in the electric box. If two or more a/c units
use the same seawater pump, the pump wires will be
connected to a pump relay panel (PRP) which in turn
has its own dedicated circuit breaker sized for the pump
(20 amp max). Please see the wiring diagram furnished
with the PRP (NOTE: PRP triac must have its mounting
screw installed in order to dissipate heat). Electrical
connections in the bilge and/or below the waterline
should use heat shrink type butt splices.
Field wiring must comply with ABYC electrical codes.
Power to the unit must be within the operating voltage
range indicated on the data plate. Properly sized fuses
or HACR circuit breakers must be installed for branch
circuit protection. See data plate for maximum fuse/circuit
breaker size (mfs) and minimum circuit ampacity (mca).
All units must be effectively grounded to minimize the
hazard of electrical shock and personal injury.
The following are to be observed:
1. AC (alternating current) grounding (green wire) must
be provided with the AC power conductors and
connected to the ground terminal (marked “GRND”) at
the AC power input terminal block of the unit(s), per
ABYC standard E-8, or equivalent.
2. Connections between the vessel’s AC system ground-
ing conductor (green wire) and the vessel’s DC (Direct
Current) negative or bonding system should be made
as part of the vessel’s wiring, per ABYC standard E-9,
or equivalent.
3. When servicing or replacing existing equipment that
contains a chassis-mounted ground stud, the service
person or installer must check the vessel’s wiring for
the existence of the connection required in item 2
above.
ABYC standards are available from:
American Boat and Yacht Council
3069 Solomons Island Rd.
Edgewater, MD 21036
Telephone: (410) 956-1050
The a/c unit must be connected to the ship’s bonding
system to prevent corrosion due to stray electrical
current or voltage. All pumps, metallic valves and
fittings in the seawater circuit that are isolated from the
a/c unit by PVC or rubber hoses must be individually
bonded to the vessels bonding system also. This will
help eliminate any possibility of corrosion due to stray
current or voltage.
FAILURE TO PROPERLY GROUND AND BOND THE
SYSTEM WILL VOID WARRANTY!
3 Phase Notice
It is extremely important to insure that wiring and phase
sequencing of a three phase power source is correct.
Marine wiring standards call for power source phases L1,
L2, and L3 to be color-coded BLACK, WHITE, and RED,
respectively. These must be connected to the unit with
the proper sequence, otherwise, it will not operate
properly. If the wiring sequence is incorrect, the unit’s
compressor (Scroll type only) and pump (if applicable)
will run in the reverse direction at a significantly in-
creased noise level.
Manual Control Panel (MCP)
Installation
The MCP should be located within cap tube length of the
a/c unit. The 3 knob MCP is configured either vertically
(shown) or horizontally. The cut out size is 2.5" by 7.0",
see MCP (Figure 6) for orientation. Once the cut out is
made, carefully uncoil the copper cap tube with return air
sensor (copper bulb) and route the control wires and cap
tube through the hole and back to the a/c unit
using
caution not to kink the cap tube . Mount the return air
sensor into the clips provided with the Vector Compact
unit. If the return air sensor cannot be mounted on the
evaporator coil, mount it behind the return air grille. The
sensor must be mounted in the return air stream. Make
electrical connections according to the wiring diagram
found in the electric box and/or in this manual. See
Figure 9.