Technical data
These ratings are in accordance with the 
following standards:
g
 ANSI/IEEE C37.04-1979 Standard 
Rating Structure for AC High-Voltage 
Circuit Breakers Rated on a 
Symmetrical Current Basis
g
 ANSI C37.06-1987 AC High-Voltage 
Circuit Breakers Rated on a 
Symmetrical Current Basis – Preferred 
Ratings and Related Required 
Capabilities
g
 ANSI/IEEE C37.09-1979 Standard Test 
Procedure for AC High-Voltage Circuit 
Breakers Rated on a Symmetrical 
Current Basis
g
 ANSI/IEEE C37.010-1979 Application 
Guide for AC High-Voltage Circuit 
Breakers Rated on a Symmetrical 
Current Basis.
Footnotes:
1.
   “xxxx” in type designation refers to the continuous current 
rating 1,200, 2,000 or 3,000 A, as appropriate. The 3,000 A  
fan-cooled rating is achieved using fan cooling as indicated in 
Footnote 4.
2.
   Maximum design voltage for which the circuit breaker is 
designed, and the upper limit for operation.
3.
   K is the ratio of the rated maximum design voltage to the 
lower limit of the range of operating voltage in which the 
required symmetrical and asymmetrical interrupting 
capabilities vary in inverse proportion to the operating 
voltage.
4.
   3,000FC indicates that fan cooling is included in the  
switchgear structure for this rating. 3,000 A rating is  
not available in outdoor equipment.
5.
   To obtain the required symmetrical interrupting capability of a 
circuit breaker at an operating voltage between 1/K times 
rated maximum design voltage and rated maximum design 
voltage, the following formula shall be used: Required 
symmetrical interrupting capability = rated short-circuit 
current (I) x [(rated maximum design voltage)/(operating 
voltage)]. For operating voltages below 1/K times maximum 
design voltage, the required symmetrical interrupting 
capability of the circuit breaker shall be equal to K times rated 
short-circuit current.
6.
   Within the limitations stated in ANSI/IEEE C37.04-1979, all 
values apply to polyphase and line-to-line faults. For single 
phase-to-ground faults, the specific conditions are stated in 
clause 5.10.2.3 of ANSI/IEEE C37.04-1979.
7.
   Current values in this row are not to be exceeded even for 
operating voltage below 1/K times rated maximum design 
voltage. For operating voltages between rated maximum 
design voltage and 1/K times rated maximum design voltage, 
follow Footnote 5.
8.
   Current values in this row are independent of operating 
voltage up to and including rated maximum voltage.
9.
   “Nominal 3-phase MVA class” is included for reference only. 
This information is not listed in ANSI C37.06-1987.
10.
  Standard duty cycle is CO - 15s - CO.
11.
   Three-cycle (50 ms) interrupting is optionally available.
Technical data
23
Measure parameter Units
Circuit 
breaker type
1
38-3AH3-
1500
General
Nominal voltage class kV 38.0
Nominal 3-phase MVA 
class
9
MVA 1,500
Rated values
Rated voltage
Maximum design voltage (V)
2
kV rms 38.0
Voltage range factor (K)
3
---- 1.65
Insulation levels Withstand voltage levels
Power frequency kV rms 80
Lightning impulse 
(BIL)
kV peak 150
Rated current
Continuous current
4 
A rms
1,200
2,000
3,000FC
Short-circuit (at rated maximum 
design voltage) (I) 
5, 6, 10
kA rms sym 21
Interrupting time
11
ms
cycles
83
5
Permissible tripping delay (Y) Sec 2
Related 
required 
capabilities
Current
Rated maximum design voltage  
(V) divided by K (=V/K)
kA rms 23
Maximum symmetrical interrupting  
(K x I)
7
kA rms sym 35
Short-time current (K x I)  
(three- Seconds)
kA rms sym 35
Closing and latching 
(momentary)
Asymmetrical (1.6 x K x I)
8
kA rms 56
Peak (2.7 x K x I)
8
kA peak 95
Table 2: Type 38-3AH3 circuit breaker ratings (historic “constant MVA” ratings basis)










