Mars Air Systems L-2254 manual Electrical Connections, Grounding and Bonding, Phase Notice

Models: L-2254

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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.

L-2254 Installation

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Mars Air Systems L-2254 Electrical Connections, Grounding and Bonding, Manual Control Panel MCP Installation, Phase Notice