Shutting down and restarting the dryer
HDK-CNG_EN_03_2016
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Emergency shutdown
In the event of an emergency, shut down the dryer as described in the next
section.
Depressurise the dryer and shut it down
In order to switch the dryer into a safe state, proceed as described in the next
three sections:
► Close the owner-installed natural gas outlet valve.
► Close the owner-installed natural gas inlet valve.
► Leave the dryer switched on until each vessel has run through an expansion
phase.
The expansion phase causes pressure in the vessels to be relieved successively
down to compressor inlet pressure.
► Check the pressure relief of the dryer on both pressure gages. It should show
'0 bar' above the compressor inlet pressure.
Disconnect voltage supply
► Switch on dryer: to this end, pressing the key S3 for longer
(>3s) and than briefly pressing the key S2.
► Close owner-installed regeneration gas return valve.
+
key S3 + key S2
► Switch OFF of the power supply to the dryer.
If work is to be carried out on the electrical system
► Depressurise and shut down the dryer, following the instructions in the above
chapter.
Risk of injury due to voltage-carrying parts!
The electrical supply cable and external power lines are live even after the
dryer is switched off and, in the event of body contact, may cause serious
injury! Before carrying out any work on the electrical system, the
electrical supply cable and all external power lines must be made voltage-
free!
► Make the electrical supply cable to the dryer voltage-free.
► Secure the electrical supply cable to the dryer against switch-on.
Re-start
Depending on the fittings installed by the operator and the actual pressure
conditions, the unit might have to be restarted at operating pressure. The
following general rules apply:
When switched off, the dryer is locked in main flow direction.
The vessel pressure drops (with opened owner-installed natural gas outlet
valve) if natural gas is being sourced from the grid.
