D) Case Grounding; E) Battery Selection And Sizing - NewMar 12-1800IC Installation & Operation Manual

of these marks. Hang the inverter/charger onto the bulkhead using the "keyhole" slots.
Doing this will save you from having to support the unit's weight while you are driving in the
four permanent mounting screws. Note: The "keyhole" slots may be used for additional sup-
port screws but they are not to be used as a permanent mounting points, by themselves.
IMPORTANT: Although the inverter/charger is constructed of materials and in a manner
which makes it resistive to the corrosive effects of the marine environment the unit is not
waterproof. Do not mount the charger where there is a possibility of water entering the unit.
Evidence of water entry into the charger will void the warranty.

D) Case Grounding

The case of the inverter/charger must be properly grounded to ship's ground*.
*Per ABYC A-20: A DC chassis grounding conductor shall be connected from the case of
the battery charger to the engine negative terminal or its bus, and must not be more than
one size under that required for the DC current-carrying conductors.
For example, if the installed battery wiring (see Wire Size Chart in section F) is 1 AWG, then
the minimum size of the grounding cable is 2 AWG. Use stranded copper wire for case
grounding. A screw compression lug located on the right-hand side of the unit is provided for
attaching the ground wire to the case. The lug accommodates wires up to 1/0 AWG. A flat
blade screwdriver is required to tighten the lug.

E) Battery Selection and Sizing

The inverter/charger should only be wired to deep cycle lead-acid batteries of flooded, gel or
AGM construction. The battery bank should be a dedicated inverter (or house) bank. It
should not be connected to batteries which are designed primarily for engine or generator
starting. Those batteries are not designed for repeated deep discharges which are common
with inverter operation.
There are quite a number of variables which can influence the proper size of a battery system
(expressed as amp-hour capacity) which is used in conjunction with an inverter. Some of
these include:
! Battery type
! Discharge rate
! Intermittent or continuous operation
! Ambient temperature
! Time between recharge cycles
! Depth of discharge
No single formula can practically cover all these variables, however, a general calculation
may be used which assumes no extraordinary variable (such as very high or low tempera-
tures in the battery environment) to make an educated estimation of the proper battery size.
The result can then be adjusted up or down to compensate for unusual circumstances.
P.O. Box 1306
Newport Beach,
California 92663
www.newmarpower.com
Phone: 714-751-0488
Fax: 714-957-1621
E-Mail: sales@newmarpower.com
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