Layout of purge air regulation for reducing air consumption
Application note
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Energy management function at adsorption dryer PDAD
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1.10 Page 16 of 17
4.
Connect external switching logic (NC contact of the manual switch, the pressure switch or on the relay) to
terminals 1 and 2 in the plug insert of the DIN plug. Make sure that the wires and cables are correctly
stripped and that good insulation is assured through the cable gland!
5.
Measure continuity between the two wires if possible with a measuring instrument, in order to ensure
that the switch is current-free in the closed position. Check for correct switching function if possible as
well. A 5 V DC signal is read out from terminal 1 during operation which is fed to terminal 2 via the NC
contact, by means of the EM function can be activated or deactivated.
6.
Carefully pull the cable back through the sleeve until the insert snaps back into the housing of the DIN
plug. Observe the direction in which the cable throughfeed must point.
7.
Insert the DIN plug back into the energy management connection at the dryer and screw it tight, making
sure that the sealing ring is correctly seated. The protective conductor terminal is somewhat wider than
terminals 1 and 2. Make sure that the socket plug is correctly aligned.
The selected cable to the switching logic …
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must have at least 2 conductors. Additional conductors may be useful in the event that a conductor is
broken. Conductors can be changed without having to lay a new cable.
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may not have a wire cross-section of any greater than 1.5 sq. mm (recommended) in order to freely fit
into the DIN plug insert.
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should have an outside diameter of no more than 6
mm. Larger diameters don’t fit well into the cable
gland of the DIN plug for the energy management function.
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should demonstrate insulation characteristics which are suitable for the conditions of use.
8.
Restart the dryer in accordance with the operating instructions.
9.
Test the energy management function (switch manually or by adjusting the switching points) without yet
discharging compressed air! Recommendation: shut-off device (2/2 function) downstream from the PDAD
10.
If reliable functioning is assured, slowly open the shut-off device and release compressed air to the
application.
11.
Renewed testing and long-term observation of the EM function, as well as adjustment of the switching
points during normal operation. Pressure, as well as the pressure dew point, should not drop to below
the minimum requirement!
Supplementary notes for the operating instructions:
The use of an ideal air reservoir downstream from the PDAD smooths pulsation caused by discharging air.
The pressure dew point to be achieved is based on the flowing quantity of air. Consequently, a higher pressure
dew point is achieved with a lower flow velocity. On the other hand, a higher or excessively high flow rate may
result in a reduced pressure dew point. For this reason, the table values listed in the catalogue should always be
complied with. The dischargeable flow rate is listed there depending on the size of the PDAD, operating pressure,
the available amount of air and the required pressure dew point.
