Time Current Characteristic Curves
60
10
10
100
1000
1
0.1
0.01
0.01
0.1
1
10
100
1000
10,000
0.1
1
1 Cycle
1 Cycle
T
ime in Seconds
T
ime in Seconds
I
g
= %I
n
(1) Continuous Ampere Setting Region
The allowable continuous operating amperes is set to a percentage of
the rating plug value. Note that the maximum continuous ampere is set
by the rating plug value, I
r
.
(2) Long Time Delay Region
The long time delay is set to an inverse I
2
t ramp function delay
calibrated at 6 times the rating plug value, I
r
.
(3) Short Time Pickup Region
The short time pickup is set to a multiple of the rating plug value, I
r
.
(4) Short Time Delay Region
The short time delay is set to either a fixed delay (illustrated) or an
inverse I
2
t ramp function delay calibrated at 8 times the rating plug
value, I
r
.
(5) Instantaneous Pickup Region
The instantaneous pickup is set to a multiple of the rating plug value, I
r
.
(6) Ground Fault Pickup Region
Ground fault pickup is set to a percent of the frame ampere rating, I
n
.
(7) Ground Fault Delay Region
The ground fault delay is set to either a fixed delay (illustrated) or an
inverse I
2
t ramp function delay calibrated at one half the frame ampere
rating, I
n
.
Amperes in Multiples of Rating Plug Value (I
r
)
1
2
3
4
5
6
7
Amperes in Multiples of Rating Plug Value (I
n
)
(1) Continuous Ampere Setting Region
The allowable continuous operating amperes is set to a percentage of
the rating plug value. Note that the maximum continuous ampere is set
by the rating plug value, I
n
.
(2) Long Time Delay Region
The long time delay is set to an inverse l
2
t ramp function delay
calibrated at 6 times the rating plug value, I
n
.
(3) Short Time Pickup Region
The short time pickup is set to a multiple of the rating plug value, I
n
.
(4) Short Time Delay Region
The short time delay is set to either a fixed delay (illustrated) or an
inverse l
2
t ramp function delay calibrated at 8 times the rating plug
value, I
n
.
(5) Instantaneous Pickup Region
The instantaneous pickup is set to a multiple of the rating plug value, I
n
.
(6) Ground Fault Pickup Region
Ground fault pickup is set to a percent of the max rating.
(7) Ground Fault Delay Region
The ground fault delay is set to either a fixed delay (illustrated) or an
inverse l
2
t ramp function delay calibrated at one half the max rating.
I
g
= % (MAX RATING)
