12-21-98
SB98107 Rev. A
Typical Voltage Agency*
Rated Interrupting Pre-arcing2Typical Total Clearing2Drop Volts at Approvals
Current Voltage Rating1I2t (A2sec) I2t (A2sec) 100% Rated
Rating AC (Max.) DC (Max.) AC DC AC DC AC DC Current
⁄Ω¡§ 125V 125V 50A 300A 1.1 ≈10-6 1.0 ≈10-7 1.8 ≈10-6 1.5 ≈10-7 2.33 ••
⁄Ω• 125V 125V 50A 300A 4.3 ≈10-6 7.1 ≈10-7 7.3 ≈10-6 8.7 ≈10-7 1.52 ••
⁄Ω¢ 125V 125V 50A 300A 8.0 ≈10-5 1.0 ≈10-6 1.2 ≈10-4 1.3 ≈10-6 .76 ••
‹Ω• 125V 125V 50A 300A 9.7 ≈10-5 6.7 ≈10-6 1.1 ≈10-4 8.3 ≈10-6 .73 ••
⁄Ω™ 125V 125V 50A 300A 7.4 ≈10-4 5.4 ≈10-5 6.2 ≈10-3 6.8 ≈10-5 .65 ••
‹Ω¢ 125V 125V 50A 300A 1.3 ≈10-3 7.4 ≈10-5 7.5 ≈10-2 9.2 ≈ 10-5 .55 ••
1 125V 125V 50A 300A .01 .01 .02 .01 .24 •••
1⁄Ω™ 125V 125V 50A 300A .03 .02 .04 .03 .20 •••
2 125V 125V 50A 300A .09 .07 .11 .08 .16 •••
2⁄Ω™ 125V 125V 50A 300A .19 .14 .25 .17 .15 •••
3 125V 125V 50A 300A .35 .28 .45 .32 .15 •••
3⁄Ω™ 125V 125V 50A 300A .56 .37 .83 .43 .14 •••
4 125V 125V 50A 300A .96 .67 1.37 .77 .13 •••
5 125V 125V 50A 300A 1.82 1.34 2.53 1.51 .11 •••
7 60V 90V 50A 300A 1.48 .49 2.02 .58 .10 ••
10 60V 90V 50A 300A 3.62 1.16 4.41 1.38 .08 ••
*Approvals: UL Recognition STD 248-14, Guide JDYX2, File E19180; CSA Certification, Class 1422-01, File 53787.
JIS (Japanese Industrial Standard) Reg. No. 2221, Authorization No. 32-1516.
1. Interrupting ratings were measured at 100% (⁄Ω¡§ to 5) and 100% (7, 10) power factors on AC, and a time constant less than 1ms. on D.C.
2. I2t was measured at 50 amps 125 VAC, .95PF, (random closing angle) and 300 amps 125 VDC, TC <1ms. for ⁄Ω¡§ through 5 amps and 50 amps 60 VAC, .95PF, (random
closing angle), and 300 amps 90 VDC, TC <1ms. for the 7 and 10 amp fuses.
Note: All values shown above are typical.
Microtron®Printed Circuit Board Fuses MCR
.122∑ ≈ .297∑ (3.10mm ≈ 7.54mm)
Form No. MCR
Page 1 of 2
BIF Doc #2003
Bussmann®
Dimensional Data
1.13"
28.58mm .297"
7.54mm
.12"
3.10mm
.025"
0.64mm
1.13"
28.58mm
*All tolerances: ±0.13mm
±0.005"
Actual Size
R
AMPERE
RATING
1/16
1/2
3/4
1/8
1/4
3/8
1.0 1.5
2.0 2.5
4.0 5.0
7.0
10.0
3.0
CURRENT IN AMPERES
10
1
.1
.01
.001
TIME IN SECONDS
1
.1
10
100
.01
Time-Current Characteristic Curves–Average Melt
(Full Size Curves Available)
Product Rated Current
Symbol
Package Code
Blank10 in
BK 500 in
TR/ Tape/Reel 2500 units, 52.4mm spacing
TR1/ Tape/Reel 5000 units, 52.4mm spacing
TR6/ Tape/Reel 1000 units, 52.4mm spacing
Radial leaded versions available (.4∑, .6∑spacing)
Weight = 2.45 lbs/2500
Time-Current Characteristics:
Rated Percent of Rating
Current 100% 250%
0-10A 4 hrs. (min) 5 sec. (max)
(See Table)MCR
Product Name: MCR (Microtron®)
Characteristics: Fast Acting, Current Limiting
Construction: Solid Matrix
Packaging & Ordering Information:
UR
CSA
JIS
Electrical Characteristics
CE logo denotes compliance with European Union Low Voltage Directive
(50-1000 VAC, 75-1500 VDC). Refer to BIF document #8002 or contact
Bussmann Application Engineering at 314-527-1270 for more information.
12-21-98
SB98107 Rev. A
Microtron®Printed Circuit Board Fuses MCR
.122∑ ≈ .297∑ (3.10mm ≈ 7.54mm)
Bussmann®
Form No. MCR
Page 2 of 2
BIF Doc #2003
The only controlled copy of this BIF document is the electronic read-only version located on the Bussmann Network Drive. All other copies of this document are by definition uncontrolled. This bulletin
is intended to clearly present comprehensive product data and provide technical information that will help the end user with design applications. Bussmann reserves the right, without notice, to change
design or construction of any products and to discontinue or limit distribution of any products. Bussmann also reserves the right to change or update, without notice, any technical information con-
tained in this bulletin. Once a product has been selected, it should be tested by the user in all possible applications.
R
Voltage Drop
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percent of Rated Current
MCR-⁄Ω¡§
MCR-‹Ω•
MCR-⁄Ω¢
MCR-⁄Ω•
MCR-⁄Ω™
MCR-‹Ω¢
Voltage Drop
0.25
0.2
0.15
0.1
0.05
0
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percent of Rated Curent
MCR-1
MCR-1⁄Ω™
MCR-2
MCR-2⁄Ω™
MCR-3
MCR-3⁄Ω™
MCR-5
MCR-10
MCR-4
MCR-7
Typical Voltage Drop (At 25° C Ambient Temperature)
Body High temperature thermoplastic,
flammability rating UL 94 VO.
Electrical Characteristics Carry 100% rated current for 4 hours
minimum. Open at 250% of rated
current in 5 seconds maximum.
Element Solid Matrix, gold or silver element
encapsulated in ceramic.
Leads Tin-plated copper, .64mm (.025∑)
diameter.
Lead Bend Test With a two pound weight attached, 90°
one direction, back to original position,
then 90° opposite direction; fuse will
withstand two cycles.
Life Test 2000 hours at 80% rated current,
55°C.
Moisture Resistance MIL-STD-202, Method 106, 90%
relative humidity at 65°C.
Operating Temperature -55°C to 125°C with proper fuse
derating.
Packaging EIA-STD-296-E.
Resistance to MIL-STD-202, Method 210, Test
Soldering Heat Condition C (260°C).
Salt Spray MIL-STD-202, Method 101, Test
Condition B.
Shock MIL-STD-202, Method 213, Test
Condition I, 100G’s for 6 milliseconds.
Solderability MIL-STD-202, Method 208.
Terminal Strength MIL-STD-202, Method 211, Test
Condition A, will withstand 7 lb. axial pull
test.
Thermal Shock MIL-STD-202, Method 107, Test
Condition B, -65°C to 125°C.
Thermal Cycle EIA-STD-RS-186-C, Test Condition A,
-55°C to 85°C.
Vibration MIL-STD-202, Method 204, Test
Condition C, (55 to 2000 HZ, 10G’s
peak).
Wave Soldering Maximum reservoir temperature 260°C,
10 second maximum exposure, .125"
from body.
Microtron fuses are designed to meet the following specifications:
