Atec High-Voltage-VLF-28CMF - Manual (Page 7)

PEAK
KILOVOLTS
0
60
CABLE CAPACITANCE
MICROFARADS
0
60
0 6.0
OUTPUT PEAK MILLIAMPERES
SCOPE
POS
NEG
60
30
10
METER
μF
mA
CAPACITANCE
SCALE X10
PUSH TO READ
X1
CAP
ZERO
7
VLF-6022CM
Front Panel
Selecting a VLF Model
There are three main considerations when selecting the appropriate model : voltage, mF rating, mF rating at 0.1Hz.
Voltage: What is the voltage rating of the cables to be tested? Below is a summary of the IEEE test voltages
recommended. While IEEE400.2 does not include HV cable classes, field experience shows the test voltage used is
1.5 – 2 times normal line-to-ground.
Simple to use,
manual controls.
No programming
necessary.
Automatic Data
Logger option.
Simple to use yet
full data capture.
μF Rating at 0.1Hz: If the VLF is to be used as a voltage source for performing Tan Delta and Partial Discharge test-
ing, then the load rating at 0.1Hz is important, as this is the frequency that these tests are performed. If the VLF is to
be used for hipoting, then any frequency from 0.1Hz - 0.01Hz can be used, unless otherwise specified.
Cable Rating Installation Acceptance Maintenance
phase to phase phase to ground phase to ground phase to ground
kVrms kVrms (kVpk) kVrms (kVpk) kVrms (kVpk)
5 9 (12) 10 (14) 7 (10)
8 11 (16) 13 (18) 10 (14)
15 18 (25) 20 (28) 16 (22)
25 27 (38) 31 (44) 23 (33)
35 39 (55) 44 (62) 33 (47)
*46 51 (72) 58 (81) 43 (61)
*69 76 (106) 86 (119) 65 (89)
μF Rating: VLF hipots are rated by the capacitance of the loads they can test. To select the appropriate VLF model,
either the load capacitance must be known or the cable length if the mF/km or pF/ft is known.
*Proposed in the next revision of IEEE400.2