Program 1 - Pepperl+Fuchs Bebco EPS 5500 Series User Manual

4.4.1

Program 1

Program 1 is used in hazardous gas atmospheres.
Sequence of Events for Program 1
Purge
P < P4 valve
ON
Pre-Purge
The purge valve (SV) is immediately energized regardless of enclosure pressure.
z
If enclosure pressure goes above P4 during purging, SV will shut off but will energize when below
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P4. Oscillation of SV may be noticed.
Setting the pressurization valve on the manifold must be done after purging, or the power to SV
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will have to be interrupted to set this pressure. The solenoid valve on the manifold is immediately
energized before this pressure can be set.
The purge timer begins counting down when the enclosure pressure is greater than P3. Enclo-
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sure pressure must remain greater than P3 to purge successfully. If the pressure drops below P3
at any time, or for any length of time, the purge timer is reset and will not begin counting down
until pressure is greater than P3
Operation Mode
After the purge timer counts down, the SV shuts off and K1 is energized.
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If enclosure pressure drops below P2, the SV is energized and will stay energized for the value of
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HYST (%, leakage compensation). If HYST is set to 0, leakage compensation is turned off.
If enclosure pressure drops below P1, K1 remains on and an alarm shall be implemented. K2 can
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be set to P- or Alarm to indicate below safe or operating pressure.
If enclosure pressure goes above P4, K1 remains. If K2 is set up as Alarm, K2 will energize.
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WARNINg!
If K1 is used to energize power to the enclosure, K1 will remain energized if
pressure is below P1 during system operation. An alarm is required and must be
located such that an operator will be notified of the alarm.
Start
P > P3
timer
t=0
5500 S
erieS
HYST > 0
Purge valve
P < P2
ON
K1 ON
Purge valve
P > P2
OFF
Bypass
ON
In menu
M  P
anual rograMMing
K1 ON
P < P1
K2 ON
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