Information On Battery Power - Norcold DE-540 Owner's Manual

Defrosting
Remove food contents and set the On-Off switch to the "Off"
position. When frost has melted, wipe the compartment plates
with a soft dry cloth and remove excess water from drip pan.
Do not use sharp objects to chip ice from the cooling plates.

Information on battery power

The battery power required for the operation of the refrigerator
is dependent upon the number of DC appliances being used, the
type of operation desired and cycling pattern desired.
A battery must also be sufficiently charged to prevent overdraw.
A battery is rated usually in ampere-hours; that is, it is capable
of sustaining it's rated ampere capacity for a period of one hour.
If the total amperage load of the vehicle is high (25 amperes),
then the installation of a 72 ampere-hour battery will not provide
the required power for any length of time unless it is aided by a
recharging source such as an alternator or generator.
Various load requirements of the vehicle's DC system dictate
the ampere-hour capacity that should be installed.
Refer to Figure 10 for the suggested dual-battery wiring dia-
gram. You will note that in this diagram there are 2 separate bat-
tery sources. One source is the vehicle or car battery used exclu-
sively for the operation of the engine and accessory equipment
such as head lights. The other source is for the operation of the
DC appliances within the recreational vehicle or boat. This battery
source is referred to as the accessory or house battery and is
used solely for that purpose.
Both of these battery sources are charged by one alternator or
generator which is powered by the vehicle engine. This charging
device should be of adequate amperage rating so that a short
engine run will bring the batteries up to full charge. The standard
alternator has a minimum rating of 60 amperes.
Check your voltage regulator or cut-out for correct charging
level. Voltage should be 13.5 to 14.5. volts to the battery.
Important Points Regarding Battery-Powered
Sources
The dual battery switch or battery isolator is an important com-
ponent as it permits the alternator or generator to charge both
the accessory battery and the vehicle battery during operation of
the vehicle engine. However, it limits the current draw of the DC
appliances to the accessory battery source when the engine or
vehicle is idle or stopped. Thus it assures that the vehicle battery
is fully charged for starting the engine. The batteries referred to in
Figure 10 are two 6 volt golf cart batteries connected in series to
provide 12 volts. Golf cart batteries are suggested for the follow-
ing reasons:
1. Larger plate construction.
2. Deep draw characteristics.
3. High ampere-hour rating.
The standard golf cart battery has a rating of approximately
185-205 ampere-hours. When two of these batteries are con-
nected in series, the result is 12 volt DC at 185 or 205 ampere-
hour capacity.
The DC supply to the refrigerator is connected to the negative
post of one battery and to the positive post of the other battery.
The power converter or solid state battery charger shown in Fig-
ure 8 is an essential item for battery-operated systems.
The converter is operated on 120 volt AC and should have an
output rating of 12.6-l4.5 volts DC at approximately 20-50 ampere
capacity. During 120 volt operation, the converter is used to
charge the batteries and to operate the DC appliances. It has the
capacity to operate items such as lighting, water pumps, exhaust
fans, and sanitary facilities while maintaining or charging the bat-
teries. Charging rate varies from 5-20 amperes per hour.
The Norcold dual voltage refrigerator automatically switches
from AC to DC or from DC to AC. When a power supply of 120
volts AC is connected to the vehicle, the voltage selection relay is
energized and disconnects the unit from DC operation. This
unique feature assures 120 volt operation when available and per-
mits the power converter to concentrate it's charging facilities to
the batteries or to other DC appliances.
When the AC supply is disconnected, the refrigerator automat-
ically reverts to DC operation. Setting the On-Off switch to the
"OFF" position will prevent operation on AC or DC.
The following are suggestions for efficient operation of the re-
frigerator:
1. The thermostat dial is numbered from 1 through 5, with the
number 5 setting the maximum coldest position. In order to
conserve battery power, it is advisable to set the thermostat
dial at the lowest setting that will provide adequate refrig-
eration. This practice will reduce the running time of the
refrigerator and draw less current from the battery. A setting
of 3 is a normal position.
2. Always operate the refrigerator on 120 volts AC when avail-
able, especially during initial start-up or pull-down cycle of
the refrigerator. Depending upon the ambient temperature,
the initial start-up may require 1-2 hours of continuous op-
eration before refrigerator temperature are attained and unit
cycling begins.
3. Never employ "quick-chargers" to the battery unless the On-
Off switch is set to the "OFF" position or the 12-volt DC
leads to the refrigerator are disconnected. Possible inverter
damage will occur if the high voltage of "quick chargers" is
permitted to energize the DC circuits of the inverter.
4. The use of a commercial 12-volt DC to 120-volt DC solid
state inverter, converter, gasoline or belt-driven generator
with 120 volt AC output is not recommended for operating
the refrigerator unless the manufacture of the foremen-
tioned devices guarantee the output voltage to be 120 volts
AC plus or minus 10 percent and the frequency to be 60
hertz plus or minus one hertz. Devices that cannot meet the
specified tolerances do not hold the required frequency,
provide poor performance of the refrigerator, and damage
the resonance springs in the compressor.
5. When connecting the refrigerator to the DC supply, observe
the correct polarity. If the polarity is reversed (positive con-
nected to negative terminal), the circuit protection will shut
the unit down. The wire leads must be disconnected and
reconnected properly, and circuit breaker reset.
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