BULLET
™
CLASS RK5
DUAL ELEMENT TIME-DELAY FUSES
Catalog Number ECNR (.1 - 600A) 250 Volts AC or Less
Catalog Number ECSR (.1 - 600A) 600 Volts AC or Less
AMPERE RATINGS
ECNR 250V
3.2
10
3.5
12
4
15
4.5
17.5
5
20
5.6
25
6
30
6.25
35
7
40
8
45
9
50
ECSR 600V
3.5
12
4
15
4.5
17.5
5
20
5.6
25
6
30
6.25
35
7
40
8
45
9
50
10
60
ECNR/ECSR SPECIFICATIONS
Dual-Element Time-Delay
60
70
75
80
90
100
110
125
150
175
200
70
75
80
90
100
110
125
150
175
200
225
225
250
300
350
400
450
500
600
—
—
—
250
300
350
400
450
500
600
—
—
—
—
0.1
0.12
0.15
0.2
0.25
0.3
0.4
0.5
0.6
0.8
1
0.1
0.15
0.2
0.25
0.3
0.4
0.5
0.6
0.8
1
1.12
1.12
1.25
1.4
1.5
1.6
1.8
2
2.25
2.5
2.8
3
1.25
1.4
1.5
1.6
1.8
2
2.25
2.5
2.8
3
3.2
Voltage Rating:
Ampere Rating:
Interrupting Rating:
Current Limiting:
ECNR - 250VAC, ECSR - 600VAC
.1 - 600 Amps
200,000 RMS Symmetrical Amps
RK5 Fuse
Agency Approvals:
UL Listed, Class RK5, Guide JDDZ, File E162363
CSA Certified HRCI-R per C22.2, No. 248.12
Self-Certified DC Ratings:
Voltage Rating:
ECNR (.1-600) 125VDC
ECSR (.1-600) 300VDC
Interrupting Rating:
ECNR/ECSR 20,000 Amperes DC
BENEFITS:
• True dual - element construction allows sizing of 125%
FLA for motor backup protection.
• Superior overload and cycling capabilities.
• Current limiting; provides component short-circuit protec-
tion.
APPLICATIONS:
• Recommended for AC power distribution system mains,
feeders, and branch circuits.
• Protection of motors and motor branch circuits.
• Protection of transformers and other inductive loads.
• All general - purpose applications including lighting, heat-
ing and other non-inductive loads.
RECOMMENDED FUSEBLOCKS:
Refer to page 136 in this catalog.
RECOMMENDED UPGRADE:
Class RK1 (LENRK/LESRK) for greater degree of short cir-
cuit protection.
CROSS REFERENCE
BUSSMANN
GOULD
FRN-R
TR
FRS-R
TRS
VOLTS
250
600
EDISON
ECNR
ECSR
LITTELFUSE
FLNR
FLSR
1
BULLET
™
CLASS RK5
DUAL ELEMENT TIME-DELAY FUSES
ECNR/ECSR dual element FUSES
These fuses are recommended for AC power distribution
system mains, feeders and branch circuits having inductive
loads (motors, transformers) or non-inductive loads (light-
ing, heating) where the available short-circuit current does
not exceed 200,000 RMS symmetrical amperes. These
“dual element, time-delay” fuses have minimum industry
standard time-delay of 10 seconds at 5 times the fuse rating
(8 sec. minimum for 250V, 30A and less). The time-delay
characteristics of these fuses typically allows them to be
sized closer to the running ampacity of inductive loads to
reduce cost and provide improved overcurrent protection.
These fuses will override normal equipment current surges
to reduce unnecessary fuse openings. They are the most
popular fuses used in the industry and the most economical
for most applications, especially motors and transformers.
They have moderate current limitation.
CLASS R FUSES WILL FIT CLASS H, K AND R FUSE CLIPS. CLASS R FUSE CLIPS WILL ONLY ACCEPT CLASS R
FUSES. FUSES RATED 600 VOLTS AC OR LESS MAY BE APPLIED AT ANY LOWER VOLTAGE. CONTACT EDISON
FUSEGEAR FOR SPECIAL PRODUCTS OR APPLICATIONS.
DIMENSIONS
(1)
Ferrule Design–0 through 60 Amperes
Knife Blade–70 through 600 Amperes
Catalog
Number
ECNR
250V
ECSR
600V
Amps
0-30
35-60
70-100
110-200
225-400
450-600
0-30
35-60
65-100
110-200
225-400
450-600
Overall
Length
A
2
3
5.88"
7.13"
8.63"
10.38"
5
5.5
7.88
9.63
11.63
13.38
Max
Diameter
B
.56"
.81"
1.06"
1.56"
2.06"
2.59"
.81
1.06
1.11
1.61
2.34
2.88
(1)
Dimensions in inches.
2
BULLET
™
CLASS RK5
DUAL ELEMENT TIME-DELAY FUSES
AVERAGE TIME/CURRENT CURVES
Cat No. ECNR (AMP) 250 VAC
.2A
.3A
.4A
.5A
.6A
.8A
1A
1.125A
1.6A
2A
2.5A
3.2A
4A
5A
6.125A
100A
200A
400A
600A
10A
15A
30A
60A
100
.1A
AMPERE
RATING
100
AMPERE
RATING
10
10
TIME IN SECONDS
1
TIME IN SECONDS
1
.1
.1
100
.1
1
10
RMS SYMMETRICAL CURRENTS IN AMPERES
600
.01
10,000
RMS SYMMETRICAL CURRENTS IN AMPERES
20,000
100
1,000
10
.01
3
BULLET
™
CLASS RK5
DUAL ELEMENT TIME-DELAY FUSES
AVERAGE TIME/CURRENT CURVES
Cat No. ECSR (AMP) 600 VAC
.3A
.4A
.5A
.6A
.8A
1A
1.125A
1.6A
2A
2.5A
3.2A
4A
5A
6.125A
8A
100A
200A
400A
600A
.1A
.2A
10A
15A
30A
100
100
10
10
TIME IN SECONDS
1
TIME IN SECONDS
1
.1
.1
100
.1
1
10
RMS SYMMETRICAL CURRENTS IN AMPERES
700
.01
10,000
RMS SYMMETRICAL CURRENTS IN AMPERES
4
20,000
100
1,000
10
.01
60A
AMPERE
RATING
AMPERE
RATING
BULLET
™
CLASS RK5
DUAL ELEMENT TIME-DELAY FUSES
PEAK LET-THROUGH CURRENT CURVES*
ECNR (250V)
ECSR (600V)
CURRENT LIMITATION TABLES
ECNR (250V)*
Available
Fault
Apparent Effective Let-Thru Amperes
Current
Fuse Ampere Ratings
RMS Amps 30A
60A
100A
200A
ECSR (600V)*
Available
Fault
Apparent Effective Let-Thru Amperes
Current
Fuse Fuse Ampere Ratings
RMS Amps 30A
60A
100A
200A
400A
600A
400A
600A
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
50,000
60,000
80,000
100,000
150,000
200,000
1,050
1,310
1,490
1,630
1,720
1,840
1,920
2,000
2,140
2,260
2,450
2,620
2,920
3,140
2,070
2,570
2,920
3,200
3,420
3,630
3,810
3,980
4,200
4,500
4,900
5,200
5,800
6,200
2,820
3,630
4,140
4,500
4,800
5,100
5,400
5,600
6,000
6,400
7,000
7,500
8,300
8,900
4,300
5,400
6,200
6,800
7,200
7,700
8,100
8,500
9,100
9,600
10,600
11,400
13,000
14,300
5,000
8,700
9,900
10,700
11,400
12,100
12,600
13,100
14,000
14,900
16,000
17,100
19,200
20,800
5,000
10,000
15,000
16,100
17,200
18,300
19,200
19,900
21,400
22,600
24,600
26,200
29,200
31,700
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
50,000
60,000
80,000
100,000
150,000
200,000
1,290
1,640
1,890
2,110
2,260
2,420
2,570
2,670
2,890
3,060
3,360
3,630
4,100
4,400
2,070
2,590
2,940
3,250
3,470
3,660
3,850
4,030
4,300
4,500
4,900
5,200
5,800
6,100
2,980
3,810
4,400
4,800
5,200
5,500
5,800
6,000
6,500
6,900
7,600
8,200
9,300
10,400
5,000
6,500
7,500
8,300
8,900
9,600
10,100
10,500
11,400
12,100
13,400
14,400
16,500
18,300
5,000
8,800
10,200
11,400
12,400
13,200
14,100
14,700
16,000
17,200
19,100
20,700
23,900
26,700
5,000
10,000
15,000
18,200
19,600
21,100
22,400
23,400
25,300
27,000
29,500
31,700
36,300
39,500
*"Apparent Let-Thru Amperes" values are read from "Peak Let-Through Current Curves" and the peak current value divided by 2.3
Asymmetry Factor.
5
