Program 5 - Pepperl+Fuchs Bebco EPS 5500 Series User Manual

4.4.5

Program 5

Program 5 is used in combustible dust atmospheres.
Sequence of Events for Program 5
P > P1
Pre-Purge
The purge valve (SV) does not come on during this operation. In a dust atmosphere, purging
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is not required. Instead, the enclosure must be cleaned of all combustible dust and then
pressurized.
The menu screen will show "CLEAN ENCLOSURE." The enclosure should be cleaned and then
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pressurized before pressing the SET button.
The enclosure pressure has to be above P1 (minimum 0.65 in wc / 1.6 mbar for dust
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atmospheres) for the SET button to work.
Operation Mode
After cleaning out and pressurizing the enclosure, the menu shows "CLEAN ENCLOSURE." To
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see the enclosure pressure, press the Down or Up button. Pressing the SET button will energize
K1.
If enclosure pressure drops below P2, the SV is energized and will stay energized for the value
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of HYST (%, leakage compensation). If HYST is set to 0, leakage compensation is turned off.
Compensation for leakages is allowed in a dust atmosphere because the enclosure is safe at this
point.
If enclosure pressure drops below P1, K1 remains on and an alarm will sound. K2 can be set to P-
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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 enclosure pressure is below P1 when K1 is used to provide power to the
enclosure during operation, K1 will remain energized. An alarm is required and
must be located such that an operator will be notified of the alarm.
P < P3
Clean
enclosure
5500 S
Purge valve
ON
K1 ON
P > P1
Bypass
ON
In menu
M  P
erieS anual rograMMing
K1 ON
P < P1
K2 ON
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