Step Function Mode (Adj. Step) - Chauvin Arnoux C.A 6549 Manual De Instrucciones

The DISPLAY key can be used to consult all information available after the measurement.
This information depends on the measurement mode selected (see § 4.2).
If the measurement was in a "programmed-time test" mode (DAR, PI, Timed Run or Timed Run + DD),
pressing GRAPH displays the insulation measurement versus time curve (see § 4.2).
Pressing T° enters the TEMPERATURE menu (see § 4.3).

5.2. STEP FUNCTION MODE (ADJ. STEP)

This test is based on the principle that an ideal insulation produces the same resistance whatever test
voltage is applied.
Any negative variation of this resistance therefore means that the insulation is defective: the resistance
of defective insulation decreases as the test voltage increases. This phenomenon is barely observed
with "low" test voltages. In consequence, at least 2500 V should be applied.
The usual test condition is a voltage increasing in steps: 5 1-min steps.
Assessment of the result:
a deviation of the resistance = f(test voltage) curve that exceeds 500 ppm/V generally indicates

the presence of mould or other deterioration.
 a larger deviation or a sudden drop indicates the presence of localized physical damage (arcing,
perforation of the insulation, etc.).
Procedure:
 In the SET-UP menu, select Set Step Function
1, 2 or 3.
Example: here, step function n°3.
 Defi ne the step function and the sample interval
is automatically adjusted..
Instr.Nr. 700016
PI (m/m)
Set Step Function 1
Set Step Function 2
Set Step Function 3
Temperature Unit
Defaut Probe Temperature
Rc Reference Temperature
ΔT for R/2
Step Function 3 :
Step
1
2
3
4
5
Total Run Time (h:m)
Sample Time (m:s)
94
SET-UP
SW Version 1.8
1.0/10
Celsius
23°C
40°C
10°C
SET-UP
Voltage
Duration (h:m)
1000V 00:01
2000V 00:02
3000V 00:03
4000V 00:04
5000V 00:05
00:15
00:30