Powered by Safety
®
9
Equipment Description
01.4IB.51000C
e. r
AtInGS
Ratings of PowlVac® switchgear and circuit
breakers are based on factors supplied in the
following:
• ANSI C37.04 Circuit Breaker Rating
Structure
• ANSI C37.06 Circuit Breaker Ratings
• ANSI C37.20.2 Switchgear Assemblies
See
Table B, Ratings of Medium Voltage PowlVac®
Metal-Clad Switchgear
for complete ratings.
Note:
Certain non-standard ratings are
available for special applications.
Consult the manufacturer for details.
Refer to the specific job drawings for
detailed voltage ratings applicable to
particular switchgear line-up.
f. l
IGhtInG
I
mpulSe
W
IthStAnD
(BIl)
The basic impulse level is 60kV for the 4.16kV
class switchgear and 95kV for the 7.2kV and
13.8kV class switchgear. The basic impulse
level testing excludes control transformers,
starting reactors, and autotransformers.
Note:
If required, Field Dielectric Tests should
be limited to 75% of Factory Dielectric
Test values. Direct current dielectric
testing is not recommended. If DC
testing is required, see
for values to be used.
Table B Ratings of Medium Voltage PowlVac® Metal-Clad Switchgear
5kV
Cell Width
inch/mm
Maximum
Voltage
Nominal
Voltage
Power
Frequency
Withstand
(kV)
BIL
Crest
(kV)
Main Bus
Continuous
Current
(A rms)
Symmetrical
short-circuit
Rating
(kA rms)
Short Time
Current
2 sec.
(kA)
Momentary
withstand
Rating
(kA Crest)
Obsolete
MVA
Rating
36/914
4.76
4.16
19
60
1200, 2000,
3000, 4000
36
36
97
250
50
50
135
350
63
63
170
500
7.2kV-15kV
Cell Width
inch/mm
Maximum
Voltage
Nominal
Voltage
Power
Frequency
Withstand
(kV)
BIL
Crest
(kV)
Main Bus
Continuous
Current
(A rms)
Symmetrical
Interrupting
Rating
(kA rms)
Short Time
Current
3 sec.
(kA)
Momentary
withstand
Rating
(kA Crest)
Obsolete
MVA
Rating
36/914
15.0
13.8
36
95
1200, 2000,
3000, 4000
25
25
67
500
36
36
97
750
50
50
135
1000
63
63
170
1500