Textron JACOBSEN R-311 69166, Technical/Repair Manual

Page: 81 / 402

4-30 4203781 First Edition
ELECTRICAL
4
Run Circuit—Theory of Operation
Unswitched Power Circuit
Unswitched power is available from the battery positive
terminal to the starter motor battery terminal and then
from the starter motor battery terminal to 50-amp circuit
breaker (F1) battery terminal. Unswitched power is
available through the 50-amp circuit breaker (F1) to
30-amp circuit breaker (F2) input terminal and from
circuit breaker (F2) input terminal to 10-amp circuit
breaker (F5).
Unswitched power is available from 30-amp circuit
breaker (F2) output terminal to the following:
• Fuel pull-in relay terminal 30
• Accessory relay terminal 30
Unswitched power is provided from 10-amp circuit
breaker (F5) to PTO switch terminal E and then from
terminal E to time delay relay +12V terminal.
Run Circuit—On Seat
The seat switch and time delay relay allow the engine to
continue to operate when the park brake is released or
when the PTO switch is in the on position.
When the operator is on the seat, the seat switch
contacts close. With the seat switch contacts closed,
voltage is provided to time delay relay enable terminal,
energizing the relay. With the relay energized, voltage is
provided to key switch terminal A from time delay relay
output terminal.
With voltage provided to key switch terminal A, key switch
terminal I continues to energize the accessory relay. The
accessory relay continues to provide voltage to the fuel
shutoff hold-in coil, keeping the fuel shutoff solenoid
plunger retracted. With the solenoid plunger retracted,
fuel continues to flow to the engine. Voltage is also
provided from the accessory relay to the fuel pump and
the pump continues to operate.
If the operator leaves the seat with the park brake in the
released position or with the PTO switch in the on
position, the time delay relay de-energizes after a 1
second delay. The time delay is to compensate for seat
bounce when operating the machine over rough terrain.
With the time delay relay de-energized, the accessory
relay de-energizes, and then the fuel shutoff solenoid
hold-in coil de-energizes, shutting off the engine.
Run Circuit—Off Seat
Before leaving the seat, the PTO switch must be in the off
position and the park brake switch in the on position. With
the PTO switch in the off position and park brake switch
in the on position, voltage is provided from the park brake
switch to key switch terminal B.
With voltage provided to key switch terminal B, key switch
terminal I continues to energize the accessory relay. The
accessory relay continues to provide voltage to the fuel
shutoff hold-in coil, keeping the fuel shutoff solenoid
plunger retracted. With the solenoid plunger retracted,
fuel continues to flow to the engine. Voltage is also
provided from the accessory relay to the fuel pump and
the pump continues to operate.