MEC 2 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER
PM056 Rev 6 05/10/15
Thomson Technology
43
8.3. SEQUENCE OF OPERATION
8.3.1. GENERAL
The MEC 2 Engine-generator controller is designed to start and stop an engine
from either a local (“manual”) or remote (“automatic”) command. When this
command is issued, the controller issues a run and crank output signal. The
controller then monitors engine speed and when crank disconnect speed is
reached, the crank signal is terminated. While the engine accelerates to normal
speed, the controller continuously monitors the engines speed signal. Should the
engine speed exceed the maximum predetermined setpoint, the over speed
shutdown fault circuit will activate, terminating the run signal. In addition to over
speed shutdown, the engine controller also monitors many other engine
protection circuits and should they be activated, the engine will be stopped
and/or alarm initiated. The engine will automatically stop for any shutdown
condition, or when the remote and/or local start signal is removed. The engine
controller operation includes time delay circuits for normal operating conditions
such as start delays, cooldown and cranking periods.
8.3.2. MANUAL START/STOP SEQUENCE
When the “RUN” pushbutton on the front faceplate keypad is pressed, an
ENGINE START DELAY timer will be initiated.
Note:
The start sequence will
not be initiated if any shutdown fault condition is present. Once the engine start
delay time expires, an engine RUN and CRANK output signal will be initiated.
Note:
The RUN output may be programmed to only energize when a start signal
is initiated and an engine speed signal is detected. Once the engine starts to
turn over and begins to accelerate to nominal speed, the controllers speed
sensor will terminate the CRANK output when engine speed reaches
approximately 20% speed (i.e. CRANK DISCONNECT speed setpoint).
Immediately upon reaching crank disconnect speed, the controller will initiate the
BYPASS DELAY time delay function. Following the BYPASS DELAY time period
(typically 10 seconds) all fault circuits programmed as BYPASS DELAY=YES will
be activated.
Note:
All fault circuits programmed as BYPASS DELAY=NO are
continuously armed irrespective of any operation sequence.
When the “OFF” pushbutton on the front keypad is depressed, the controllers
RUN output will be immediately terminated which will initiate the engine to stop.
Summary of Contents for MEC 2
Page 2: ......
