Vega VEGAFLEX 80 series Safety Manual - 7 Proof Test
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7 Proof test
VEGAFLEX 80 series • Two-wire 4 … 20 mA/HART
42960-EN-170410
7 Proof test
7.1 General information
To identify possible dangerous, undetected failures, the safety func-
tion must be checked by a proof test at adequate intervals. It is the
user's responsibility to choose the type of testing. The time intervals
are determined by the selected PFD
AVG
(see chapter "Safety-related
characteristics").
For documentation of these tests, the test protocol in the appendix
can be used.
If one of the tests proves negative, the entire measuring system must
be switched out of service and the process held in a safe state by
means of other measures.
In a multiple channel architecture this applies separately to each
channel.
•
Determine safety function (mode, switching points)
•
If necessary, remove the instruments from the safety chain and
maintain the safety function by other means
•
Provide an approved adjustment unit
Warning:
During the function test, the safety function must be treated as unreli-
able. Take into account that the function test influences downstream
connected devices.
If necessary, you must take other measures to maintain the safety
function.
After the function test, the status specified for the safety function must
be restored.
7.2 Test 1: Without checking the process variable
•
Instrument can remain in installed condition
•
Output signal corresponds to the assigned process variable
•
Device status in the menu Diagnosis: "OK"
Distance from the sensor reference point to the level
•
> 1000 mm with FX86.**4***A***** with reference distance
750 mm
•
> 750 mm with FX86.**4***A***** with reference distance 500 mm
•
> 500 mm with FX86.**4***A***** with reference distance 260 mm
•
> 300 mm with FX8*.******A***** without reference distance
1. Carry out a re-start (separate the test item at least 10 seconds
from mains voltage)
2. Press the menu item "Start proof test" in the menu Diagnosis on
the adjustment unit
Step 1: Output signal corresponds to the assigned process variable
and the device status in the menu Diagnosis is "OK"
Step 2: Adjustment unit signals "Test successful"
Objective
Preparation
Unsafe device
status
Conditions
Procedure
Expected result