Operator's Manual

Operator’s Manual ASCO 336 / 337
381333-427 A ASCO Power Technologies Page 9
Figure 7. Operator Interface Terminal (OIT) with Power Management option.
Operational Testing
Load testing on optional power management systems may be
done by turning off power management. That will start all
available generators that were shed by the generator shed
function. Individual generators may then be taken off line by
pressing the Transfer Load & Shut Down button on OIT.
The Transfer Load & Shut Down button may not shut off
a generator if doing so might overload the remaining
generator(s) or additional generator(s) are not available to take
over the load. To manually operate the system, the Semi-
Automatic (Semi) mode may be used. Semi-Automatic is also
known as assisted automatic mode. Here are two examples:
1. On the generator that is to be started to accept the load:
a. Press the Semi button.
b. Press the green 1 button.
If available, the generator will start.
c. Press the Close button.
The generator will synchronize and close to the bus.
2. On the generator that is to be shut down
a. Press the Semi button.
b. Press the Off/Cooldown button. (Off/Cooldown
may be cancelled at any time by pressing the Auto
button.)
Pressing Auto on the generator that has been shut down may
or may not return it to service depending upon the generator
shed/add status and the Run Time Management status.
In a system without power management, all generators will be
running when the Master Control Switch is in the On
position or in Auto with the customer remote control contact
closed.
No load testing may be done by selecting MAN mode from
the front panel, then press the green 1 button to start the
generator. When test is complete, press the red 0 button to
stop the generator then the Auto button to return the generator
to automatic mode.
Mode Selection
This system is designed to stay in Auto mode all the time. If
the controller is not in Auto or will not switch to Auto mode,
check the alarm log and reset any active alarms. One possible
cause is the status of the generator circuit breaker. If it trips,
the system will fault and go to manual mode.
Manual Mode may be used to run the generator for no load
test, see Operational Testing.
Semi automatic mode is also known as assisted automatic
mode. It is not often used on this system. For more details, see
the detailed documentation available on the website.
Off mode turns off the control system and takes the generator
out of system control. The Transfer Load & Shut Down
command turns off a running generator. It is necessary to press
Auto mode, either on the OIT or the controller itself to return
the system to automatic mode.
Note: The green 1 and red 0 buttons are disabled in Auto
mode. The Transfer Load & Shut Down button on the OIT
will shut down a running generator via the normal shut down
and cool down processes. An Emergency Stop will
immediately trip the CTTS contacts and immediately
shutdown a generator. Emergency Stop should not be used
on a hot, running, generator unless necessary. Engines may be
damaged if they are not allowed to follow the normal cool
down process.
Transfer Load & Shut Down button