Pin 11: This is the output to the display. The Load Manager display contains two LED's. One LED,
the green one, is illuminated whenever the +12 volts is applied to the display. This indicates that the
load management circuit is active. The red LED is illuminated by grounding the yellow wire of the
display. This is done by Pin 11 and occurs when the Load Manager senses a low voltage.
Pin 12: This is a +12 volt input which starts the sequential switching of the relays. Ap12 volts
to Pin 12 energizes the relays at approximately 1/2 second intervals. Removing the +12 volts from
Pin 12 will sequentially open the relays at approximately 1/2 second intervals. This voltage must be
12 volts or not less than .20 volts below the battery voltage. BEWARE OF LOW VOLTAGE!
Pin 13: This pin is not used and no connection should be made to it.
Pin 14: This pin turns "ON" the voltage sensor in the Load Manager. Ap12 volts to Pin 14 will
make the Load Manager shed loads that cause the voltage at Pin 1 to drop below 11.5 volts (12.3
volts for PIE units). If Pin 14 is not connected, the Load Manager is a simple sequencer. When Pin
14 and Pin 12 are simultaneously supplied with +12 volts the Load Manager will sequence the loads
"ON" and sheds excessive loads simultaneously.
ABOUT LOAD SHEDDING
The Load Manager voltage sensing circuit has been designed to react very slowly to drops in voltage.
This is necessary to eliminate nuisance shedding due to transients and temporary drops in voltage.
The actual response time in any installation can vary widely for two reasons: 1. the number and
capacity of the batteries and 2. the amount of current that the loads draw in excess of the alternator
output.
Consider two installations. The first with only a single battery and the second with six batteries in
parallel. Now, for any given overload, the voltage of the single battery will decrease much more
rapidly than the voltage of the six batteries in parallel. Thus the Load Manager will detect the
overload sooner with the single battery and start to shed loads.
Similarly for any battery configuration, if the overload, the amount that the load current exceeds the
alternator output, is larger, then the battery voltage will drop faster and load shedding will occur
sooner.
