Lincoln Electric Prism 4, Operator'S Manual

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B-3
OPERATION
SOFTWARE FUNCTION
The PRISM® is controlled by a PLC using Eaton Smartwire
technology with the following software functions.
1) START/STOP FAN - Fan start/stop is controlled by push
button on front of the Prism® control panel OR remotely by
external switch or remote control.
2) AUTOMATIC FILTER CLEANING -
a) Filter bank offline/online cleaning is dependent upon the
differential pressure across the filters and your set points.
b) Offline cleaning occurs when fan is off.
c) Online cleaning occurs when fan is on.
d) Offline filter cleaning activates at three levels of filter
pressure drop (low, medium, high). Each level gradually
increases the amount of filter cleaning.
e) Low pressure default value is 400Pa, with an adjustable
range of 300Pa to 1000Pa.
Medium pressure
default
value is 600Pa, with an adjustable range of 500Pa to
1200Pa.
High pressure
default value is 800Pa, with an
adjustable range of 700Pa to 1400Pa.
Note: "Range" is the allowed value for each setting. A value
above each set point activates cleaning at that level.
f) At the low pressure limit, the cleaning cycle is 2 rounds.
At the
medium pressure
limit, the cleaning cycle is 4
rounds. At the high pressure limit, the cleaning cycle is 6
rounds.
g) When the fan is running, filter differential pressure is
monitored. Once a level is reached, the system will wait
for the fan to shut down before offline cleaning begins. In
addition to hearing air blasts, the white light on the control
panel will flash as a visual indication that the unit is
cleaning. The white light will return to steady once the
cleaning cycle is completed. Each valve is pulsed with
compressed air in round robin fashion for the amount of
cycles indicated for that level of cleaning. On some units,
more than one valve is pulsed at a time. The default pulse
time is 250ms. After the first valve is pulsed, the next one
is delayed (default 15 seconds). The delay allows the air
accumulator tank on the filter bank to refill.
h) If the fan is turned on before the cleaning cycle has
completed, offline cleaning will pause. Once the fan is
turned off, filter cleaning will resume at the same point
where is stopped.
i) Online cleaning is activated with the filter pressure drop
settings. Default level is 1000Pa with a range of 100Pa to
2500Pa. When the fan is running and the filter pressure
set point has been reached, the Power On white light will
flash and filter cleaning will start. The same pulse and
pause times from the offline cleaning are used. Online
cleaning will not stop until the filter pressure falls below
the set point.
* The VFD alarm can be reset by pushing the reset alarm button.
* The filter change alarm only stops once the pressure across the filter is
below the alarm set point. A reset signal is sent to the VFD. If it does not
clear the alarm, you must investigate the issue at the VFD enclosure with
a qualified person able to view the LCD screen and trouble shoot the
drive using its error message.
FUNCTIONS OF THE PRISM®
FILTER UNIT:
1) Manual start/stop ventilator
2) Remote start/stop of unit along with a "running" signal
available that the remote Robotic Welding Cell can monitor.
3) Adjustable ventilator speed via a duct mounted pressure
sensor and a PID loop that controls the motor speed with a
Variable Frequency Drive (VFD).
4) Automated on line filter cleaning
5) Automated off line filter cleaning
6) Manual off line filter cleaning
7) Alarm signal (optical) for:
a. Faulted VSS (Variable Speed Starter).
b. Clogged filter
8) Reset Alarm
OPERATION
Start/Stop Fan
- Fan operation is activated with the Start/Stop
Fan push button or with the remote Start/Stop. After fan shutdown,
the green button will flash for 30 seconds before the fan can be
restarted.
NOTE: remote input takes precedence in operation. If the remote
signal starts the unit, pushing the Start/Stop Fan button on the
control panel will not stop the fans. The remote signal has to be
removed (opened) This will allow the Start/Stop Fan button to
operate normally again.
Reset Alarm
- Reset Alarm push button is used to reset the
alarm if the VFD faults. There are fault codes that can be decoded
from the LCD on the front of the VFD.
CAUTION: only qualified persons with proper protections in place
should open control cabinets under power.
Ventilation Fan Speed and Operation
- Ventilator fan is
set for proper airflow during installation by setting a PID set point
in the VFD. The fan VFD uses uses a duct mounted pressure
sensor which gives a 0-10 VDC reading back to the controls,
which allows a constant airflow to be maintained up to the limits
of the fan motor operation during filter loading. The speed of the
fan will be automatically adjusted between the minimum (20Hz)
and maximum (60Hz) speeds. Consult the VFD operation guide, or
contact Lincoln Electric service department for guidance with
PRISM ®
3) ALARMS - The PLC will trigger an alarm in the following
cases.
a) The filter change alarm default is set at 1500Pa. When
the filter differential pressure remains above this set
point for 2 hours, the alarm is activated and the red
alarm light will blink on the main control cabinet. At
this time filters should be ordered from Lincoln Electric.
b) Motor VFD faults and signals the control cabinet-- the
red alarm light is solid red.