Section III. PRINCIPLES OF OPERATION

TM5-6130-301-13&P

STA 1-12 VOLTS and STA 4-12 VOLTS (Controlled)

Output Voltage( Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 voltsdc

Output Current (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 continuous, 7 peak (15 min.)

STA 2-24 VOLTS and STA 3-24 VOLTS (Controlled)

Output Voltage (Max) . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..28 volts dc

Output Current (Max) . . . . . . . . . . . . . . . . . . . . 5 continuous, 7 peak(15min) amps dc

24 VOLTS UNCONTROLLED RECEPTACLES (8 each, Uncontrolled)

Output Voltage (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..28 volts dc

Output Current (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . 10 continuous18 peak (15min) amps dc

Section III. PRINCIPLES OF OPERATION

1.9. GENERAL.

a. To charge a battery, it is necessary to apply a voltage higher than the actual voltage of the battery so that

current will flow into the battery cells. This current is a function of the voltage applied above the actual battery

voltage and the internal resistance of the cell.

b. The flow of charging current cause heat due to the I 2R losses in the battery. A "trickle" charger provides

a low charging current so that such heat cannot become excessive but its use requires a long period of time, For

faster charging, such as with this equipment, the current provided is high and it is then up to the operator to see

that none of the batteries being charged become overheated in the charging process, (Overheating will cause

warpage of the battery plates which will ruin tile battery.)

c. This distubution panel is primarily designed to use the constant potentioal (constant volt) method for

charging batteries. Thus when a discharged or partially discharged battery is connected to an uncontrolled

station of this distribution panel the initial charging current will be high but the charging currrent will fall off as

the state of charge of the battery increases. The controlled stations of the distribution panel are designed to

use the constant potential for charging batteries, however, if the constant current method is desired

these cent rolled stations may be used by varying the rheostat for that station to keep the charging current

Constant.

d. Because battery construction varies, it is impossible to specify a "safe" charging rate for all batteries.

However, if the 8-hour discharge rate of the battery is known, the battery may be safely charged using a

charging current no higher than its 8-hour discharge current rate. For example, if a battery is rated 40 amp-

hours at an 8-hour rate divide the 40 amp-hours by the 8-hour time which gives 5 amperes. This is the safe

charging limit for the battery in this example. (A battery rated 40 amp-hours at the 8-hour rate means the

battery is capable of providing 5 amperes for 8 hours.)

e. Each of the twelve output receptacles of the distribution panel is connected to a reverse-current diode. This

prevents current flow from the battery into the circuitry of the unit. These diodes, their heat sinks, bus bars,

and other circuitry and wiring ?of the distribution panel are installed on the underside of the hinged panel.

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