CONTROL PANEL (TYPE 5)
SYSTEMS OPERATION
AUTOMATIC START/STOP SYSTEM
Introduction
The automatic start/stop system is normally used for
standby operation. That is, without an operator. The
generator set must start, pick up the load, operate the
load, and stop after the load is removed. An automatic
transfer switch controls the transfer of load to and from
the generator set. When normal (commercial) power
has a failure, initiating contactor (1), part of the
automatic transfer switch, closes. This will begin the
automatic start sequence. When the engine starts, the
control panel instruments will show voltage and
frequency. The automatic transfer switch will transfer
the load to the generator set when voltage and
frequency reach approximately rated value. When
normal power returns, the automatic transfer switch will
transfer the load back to normal power. Initiating
contactor (1) will open. This will begin the automatic
stop sequence. The generator set will also stop
automatically if the engine has a failure.
The packaged generator set has shutdown sensors,
shutdown indicators and shutdown circuit for the
conditions that follow.
1.
Low oil pressure
2.
High water temperature
3.
Overspeed
4.
Overcrank
NOTE: For specifications on components located on
the engine, make reference to the ENGINE SERVICE
MANUAL.
Automatic Start
With engine control switch (ACS) in the AUTO
position, contacts (10) and (9) are closed. When
commercial (normal) power has a failure, remote start
initiating contact (1) closes. This makes a complete
circuit from battery (BATT) to energize run relay (RR)
through normally closed contacts of the four engine fault
relays (OPR), (WTRI), (OSR1), (OCR).
When run relay (RR) is energized. contact (RR2)
opens and contact (RR1) closes. (RR2) open prevents
current flow to shutoff solenoid (SS). (RR1) closed
energizes the (MS) through a normally closed (AR2)
contact. At the same time power is applied to the
overcrank timer (OCT). A magnetic pickup relays engine
rpm to the dual speed switch (DDS). The dual speed
switch has a crank terminate (CTS) circuit and an
overspeed (OSS) circuit.
When overcrank timer (OCT) is energized, a timer
will start. After the engine cranks for approximately 30
seconds the timer will stop. (OCT) contacts will open.
Make reference to ENGINE DOES NOT START.
When magnetic switch (MS) is energized, (MS)
contacts close and pinion solenoid (PS) is energized.
This causes (PS) contacts to close, starting motor (SM)
will crank the engine.
Manual Start
The current flow for manual start is similar to
automatic start except engine control switch (ACS) is
turned to the MAN position. Contact (10) is open and
contact (11) is closed. It is not necessary for remote
start indicating contact (1) to close. Run relay (RR) and
magnetic switch (MS) will energize the same as with
Automatic Start.
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