User`s guide

4-31
Operation 4
Programming the Safety Files
The Safety Files are a useful safety feature which
can be used to control the pumping system if a mal-
function is detected. It is possible to detect if the
system pressure is too high or too
low, if there has been a power
failure, or if an external sensor has
detected an illegal value (tempera-
ture too high, for example). In this
case, the method program is
stopped, and the relevant Safety File
is run. The File number and function
of each File is listed in this table.
These programs are created in exactly the same
way as a method program. To program the low
pressure safety file, select file 11 and enter the
sequence of flow rates and input/output operations
that you require when there is a low pressure error.
Similarly, enter a program for the high pressure
safety file, Input# 2 safety file and the power
failure safety file. The Input # 2 contact can be
connected to an external safety device such as a
temperature or pressure measurement system.
An example of simple programs for the high and
low pressure safety files are given in program lists 2
and 3 at the end of this section.
Low Pressure Safety File (File 11)
If the pressure goes below the low pressure limit
the sequence of events is as follows:
• If the low pressure error file (11) contains no
program, the method program will stop and can
not resume until the operator presses the Pause
soft key followed by End.
• If the low pressure error file contains a program,
the method program will link to this file and will
run it. After file 11 is finished, if there is a link to
another file, this new file will start to run. If there
is another low pressure error during file 11, the
pump will stop and can not resume until the
operator presses the Pause soft key followed by
End.
For an example of a Low Pressure safety file refer to
page 4-39, Program List 2.
Programming the Safety Files
File Name Function
11 Low File runs after a low pressure error
12 High File runs after a high pressure error
13 Input File runs if input # 2 is activated
14 Power File runs after a power failure