PFU 780 · Edition 02.12
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6 .6 Reset
6 .6 .1 Parallel reset
Several burner control units can be reset in parallel using the
external button. The PFU cannot be reset by mains failure.
6 .6 .2 Permanent remote reset
Permanent remote reset gives rise to a malfunction. If a remote
reset signal is permanently applied to terminals 10c/12c,
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flashes on the display to indicate a fault.
Reset with a pulse < 1 s.
6 .6 .3 Automatic remote reset (PLC)
In the case of automatic remote reset (PLC), the reset pulse
duration should not exceed 1 second. Check compliance with
standards.
If a fault is acknowledged by remote reset too often, error
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(Too many remote resets) is displayed. The error can only be
acknowledged with the Reset/Information button on the unit.
The burner malfunction must be remedied. The malfunction
can not be remedied by changing the method of activation.
6 .6 .4 Burner start
A furnace start may only be initiated, if it has been ensured
using an appropriate procedure that there is no combustible
mixture in the combustion/processing chamber, in the con-
nected areas or in the exhaust gas system (heat exchanger,
dust collector). This can be achieved by pre-purge, which
occurs immediately before ignition or within the period speci-
fied in the operating instructions.
In the case of multiple burner applications, pre-purge is not
necessary after a normal burner shut-down.
Note the requirements of the Standards. For exceptions, see
Standards.
6 .6 .5 Restart and start-up attempts
The precondition for a restart/start-up attempt is that activation
of the restart allows the burner to restart as intended (in all
operating phases). In this case, it must be ensured that the
program sequence started by the PFU matches the application.
Note the requirements of the Standards. For exceptions, see
Standards.