EDISON TYPE CJ
FAST ACTING FUSES
600V a.c. or less, 250V d.c. 200,000A I.R. to CSA C22-2 No. 106 M92
Industrial Duty Fuses with Ceramic Bodies
HRCI-J fuses are usually specified to protect low voltage
distribution systems within building and light industrial installations, up to and including 600 Amp ratings. (For compatible performance above 600 Amps use Edison LCU fast-acting HRC-L fuses.)
The excellent current limiting characteristics of fast-acting
HRCI-J fuses limits damage to equipment and installations
by the thermal and magnetic energy associated with a large
short-circuit fault current. In addition, the carefully designed
overload characteristic limits cable damage due to low overload currents.
Cross Reference
EDISON
-CJ, JFL
BUSSMANN
JKS-
GOULD
CJ, A4J-
GEC
C-J
LITTLEFUSE
JLS-
D
E
F
G
H
J
K
Ratings, Categories and Dimensions
Current
Ratings
(Amps)
1
3
6
10
15
20
25
30
35
40
45
50
60
70
80
90
100
110
125
150
175
200
225
250
300
350
400
450
500
600
Catalog
Number
1CJ
3CJ
6CJ
10CJ
15CJ
20CJ
25CJ
30CJ
35CJ
40CJ
45CJ
50CJ
60CJ
70CJ
80CJ
90CJ
100CJ
110CJ
125CJ
150CJ
175CJ
200CJ
225CJ
250CJ
300CJ
350CJ
400CJ
450CJ
500CJ
600CJ
Dimensions in Inches and mm
A
B
C
2.25
57
.5
12.7
.81
20.6
–
–
–
–
–
–
–
2.38
60
.63
16
1.06
27
–
–
–
–
–
–
–
4.63
117
3.63
92
1.13
28
.75
19
.13
3.2
1
25.4
.5
12.7
.28
7.1
.38
9.5
2.63
67
5.75
146
4.38
111
1.63
41
1.13
28.6
.19
4.8
1.38
35
.69
17.5
.28
7.1
.38
9.5
3
76
7.13
181
5.25
133
2.13
54
1.63
41
.25
6.3
1.88
47.6
.94
24
.41
10.3
.53
13.5
3.38
86
8
203
6
152
2.63
66
2
51
.38
9.5
2.13
54
1
25.4
.53
13.5
.69
17.5
3.75
96
E
A
B
B
J
A
K
F
H
C
C
D
1CJ TO 60CJ
94
B
70CJ TO 600CJ
G
EDISON TYPE CJ
FAST ACTING FUSES
High Ambient Temperature
Edison CJ fuses derate with high ambient temperature by
1% per degree Celsius over 35C. For example: a 400CJ at
45°C would be rated 400 x [100 - (45-35)%] = 360 Amps.
To correctly size a fuse for distribution applications the engineer must choose a rating to carry the maximum allowable
full load current of the installation, and be certain of the following:
1. The peak current let-through, at maximum available
fault current, is less than the maximum withstand level
of the switchgear and associated equipment. This is
read from the peak let-through curves.
2. The maximum I2t let-through of the fuse at system voltage as read from the I2t curve is less than the equipment withstand levels.
3. The fuse minimum melting current (135% of its rating)
will protect the cables and equipment from overloads.
AMPERE
RATING
400
600
200
100
1,000
60
Fuse Discrimination
Discrimination with upstream fuses is obtained when the
total clearing I2t of a load side fuse is less than the melting
I2t of the fuse on the line side.
30
Time/Current-Curves
100
TIME IN SECONDS
Technical Description
10
1
.1
Unlike HRCI-R types, there is no provision for HRCI-J fuses
rated 250 volts, but Edison CJ fuses operate at any voltage
up to and including 600 VAC.
100,000
10,000
1,000
100
10
.01
CURRENT IN AMPERES
Peak Let-Through Curves
Energy Let-Through Curves
100
600
400
Total I2t at 600V
200
.1
Pre-Arcing I2t
100,000
10,000
1,000
100
10
1
.1
.01
600
400
200
100
100
60
PROSPECTIVE CURRENT (SYM. RMS KA)
30
PEAK CURRENT (KA)
AMPERE
RATING
1
Total I2t at 460V
1,000,000
AMPERE2 SECONDS (I2t)
100
60
30
10
FUSE RATING (AMPERES)
95
EDISON TYPE CJ
FAST ACTING FUSES
Fuse Applications
Motor Branch Circuit
Fuses used in motor branch circuits are generally of current
rating higher than the full load current of the motor in order
to avoid nuisance fuse operation due to motor starting
inrush currents. It should be appreciated that H.R.C. fuses
are used in motor branch circuits primarily to provide overcurrent (short circuit) protection; overload protection is usually provided by separate devices such as thermal overloads. In selecting fuses for such applications, the rating
chosen must be such as to prevent fuse operation during
starting and to ensure that under fault conditions the thermal energy and peak current let-through are such as to prevent damage to the starter, the motor and the interconnecting cable.
Method for Selecting Fuse Rating
1. From the Fuse Selection Table select the appropriate
type of motor starting conditions,
2. Select the figure in this column that is equal to or higher
than the Full Load Current of the motor. The correct
Edison HRCI-J fuse rating is shown in the left hand column.
3. The Fuse Selection Table is based on the following starting conditions:
a) Full Voltage Starting - normal duty - 6 times full
load current for 10 seconds.
b) Full Voltage Starting - heavy duty - 7 times full load
current for 15 seconds.
c) Reduced Voltage Starting - 3-1/2 times full load current for 20 seconds.
4. These notes and table are intended as a general guide
to the selections of Edison HRCI-J (CJ) Fuses. Frequent
starts, high ambient temperatures and special starting
conditions may necessitate special considerations.
Fuse Selection Table
Edison CJ
Fuse
Rating
1CJ
3CJ
6CJ
10CJ
15CJ
20CJ
25CJ
30CJ
35CJ
40CJ
45CJ
50CJ
60CJ
70CJ
80CJ
90CJ
100CJ
Full Voltage Starting
Normal
Heavy
Duty
Duty
Maximum Full Load Current of Motor
0.3
0.24
1.0
0.88
1.5
1.3
3.3
2.7
6.0
4.0
6.8
5.4
9.2
7.3
11.7
9.4
15
12
17
13
21
16
23
19
30
24
33
26
40
31
45
35
53
41
Reduced
Voltage
Starting
Rating
0.47
1.7
2.6
5.1
7.7
10.6
13.7
17.7
22
26
29
34
47
50
58
64
75
Full Voltage Starting
Edison CJ
Normal
Heavy
Fuse
Duty
Duty
Maximum Full Load Current of Motor
110CJ
58
46
125CJ
63
50
150CJ
78
61
175CJ
100
78
200CJ
117
91
225CJ
125
97
250CJ
142
110
300CJ
158
121
350CJ
200
164
400CJ
250
200
450CJ
292
229
500CJ
333
257
600CJ
417
329
Reduced
Voltage
Starting
86
93
112
143
168
180
200
229
286
357
442
500
600
Horizontal lines denote change in body size.
Steady Load Currents
Transformer Circuits
This is the simplest application of fuses and it is necessary
to ensure that the fuse runs within the allowable temperature rise by not using a fuse of normal current rating lower
than the circuit full load current. For close protection, however, the current rating of the fuse should not be greatly in
excess of the full load current.
In such applications the fuse must be capable of withstanding the magnetizing inrush current of the transformer. This
can be assumed to be about twelve times the full load current of the transformer for up to 0.1 seconds and even
greater for small transformers.
Capacitor Circuits
For power factor correction capacitors the fuse should be
chosen with a current rating greater than 1.75 times the
rated capacitor current. This takes into account the high
transient inrush current, circuit harmonics and capacitor tolerances.
Fluorescent Lighting Protection
The normal current rating of the fuse should be at least 2.5
times the total normal full load current of the maximum number of lights to be switched simultaneously.
96
The following table gives the suggested minimum current
ratings of fuses to be used in conjunction with transformers.
Above the range of this table the minimum rating of the
fuses should be 150% of the full load current of the transformer.
Transformer Full Load Current Amps
Minimum Fuse Rating - Amps
3
10
6
20
12
30
20
40
30
50