INCH-POUND
AMSC N/A FSC 5925
MIL-PRF-55629/20G
10 March 2010
SUPERSEDING
MIL-PRF-55629/20F
21 September 2005
PERFORMANCE SPECIFICATION SHEET
CIRCUIT BREAKERS, MAGNETIC, PANEL SEAL,
TRIP-FREE, SERIES TRIP, SINGLE POLE
(0.2 TO 30 AMPERES)
This specification is approved for use by all Departments
and Agencies of the Department of Defense.
The requirements for acquiring the product described herein
shall consist of this specification sheet and MIL-PRF-55629.
FIGURE 1. Dimensions and configurations (configuration 1).
MIL-PRF-55629/20G
2
Ltr Inches mm
Min Max Min Max
A .735 .765 18.67 19.43
B .641 .671 16.28 17.04
C 1.189 1.251 30.20 31.78
D 1.969 2.031 50.01 51.59
E .060 .065 1.52 1.65
F .030 .035 0.76 0.89
G .115 .145 2.92 3.68
H .199 .261 5.05 6.63
J .312 REF .374 REF 7.92 REF 9.50 REF
K 1.499 1.561 38.07 39.65
L --- 2.232 --- 56.69
M .719 .781 18.26 19.84
N .594 .656 15.09 16.66
P .365 .395 9.27 10.03
R .019 REF .021 REF 0.48 REF 0.53 REF
S .030 .035 0.76 0.89
T .079 REF .141 REF 2.01 REF 3.58 REF
U .019 REF .081 REF 0.48 REF 2.06 REF
NOTES:
1. Dimensions are in inches.
2. Metric equivalents are given for general information only.
3. Unless otherwise specified, tolerance is .031 (0.79 mm).
4. Lockwasher, split, No. 8 NASM35338-137 or equivalent.
5 Terminal screw, No. 8, .164-32 UNC-2A, .187 .015 long, material: Brass, tin plated (ASTM-B545 or
equivalent).
6. Passivated - corrosion resisting steel screw, slotted head with integral O-ring, may be replaced by the
NASM3212-12 with cross-recessed head or equivalent.
7. Hex mounting nut .500 - 32 UNF-2B thread, .625 .010 across flats, .120/.125 thick, brass nickel plated,
SAE-AMS-QQ-N-290 nonglare or equivalent; may be replaced with MS25082-B22 or equivalent.
8. Internal tooth lockwasher, .625 .005 O.D., .510 .005 I.D., .028 .005 thick, stainless steel.
9. O-ring, material: Material shall be selected to enable the O-ring to meet the performance requirements of this
specification. Butadiene acrylonitrite has been successfully used in the past and should be considered for
meeting the O-ring requirements of the specification.
10. Auxiliary switch terminals shall provide for soldered connections.
11. Physical item marking of the words “LOAD” and “CB CONT OPEN” is optional.
FIGURE 1. Dimensions and configurations (configuration 1) - Continued.
MIL-PRF-55629/20G
3
FIGURE 2. Dimensions and configurations (configuration 2) - Continued.
MIL-PRF-55629/20G
4
Ltr Inches mm
Min Max Min Max
A .735 .765 18.67 19.43
B .641 .671 16.28 17.04
C 1.205 1.235 30.61 31.37
D 1.985 2.015 50.42 51.18
E .060 .065 1.52 1.65
F .030 .035 0.76 0.89
G .115 .145 2.92 3.68
H .215 .245 5.46 6.22
J .280 .310 7.11 7.87
K 1.515 1.545 38.48 39.24
L --- 2.256 --- 57.30
M --- 2.620 --- 66.55
N .610 .640 15.50 16.26
P .735 .765 18.67 19.43
R .030 .035 0.76 0.89
S .019 .021 0.48 0.53
T .095 REF .125 REF 2.41 REF 3.18 REF
U .360 .390 9.14 9.91
V .095 .125 2.41 3.18
W .095 .125 2.41 3.18
X .245 .275 6.22 6.99
Y .329 .359 8.36 9.12
Z .055 .085 1.40 3.18
NOTES:
1. Dimensions are in inches.
2. Metric equivalents are given for general information only.
3. Unless otherwise specified, tolerance is .015 (0.38 mm).
4. Lockwasher, split, No. 8 NASM35338-137 or equivalent.
5 T erminal screw, No. 8, .164-32UNC-2A, .187 .015 long. Material: Brass, tin plated (ASTM-B545 or
equivalent).
6. Passivated - corrosion resisting steel screw - slotted head with integral O-ring, may be replaced by the
NASM3212-12 with cross-recessed head or equivalent.
7. Hex mounting nut: .500 - 32 UNF-2B thread, .625 ..010 across flats, .120/.125 thick, brass nickel plated,
SAE-AMS-QQ-N-290 nonglare or equivalent; may be replaced with MS25082-B22 or equivalent.
8. Internal tooth lockwasher, .625 .005 O.D., .510 .005 I.D., .028 .005 thick, stainless steel.
9. O-ring, material: Material shall be selected to enable the O-ring to meet the performance requirements of this
specification. Butadiene acrylonitrite has been successfully used in the past and should be considered for
meeting the O-ring requirements of the specification.
10. Auxiliary switch terminals shall provide for soldered connections.
11. Physical item marking of the words “LOAD” and “CB CONT OPEN” is optional.
FIGURE 2. Dimensions and configurations (configuration 2) - Continued.
MIL-PRF-55629/20G
5
REQUIREMENTS
Dimensions and configuration: See figure 1 and figure 2.
Current ratings: See table I.
High inrush: Applies unless otherwise specified. 1/
Voltage ratings: See table II. Ratings are maximum; the minimum operating voltage is limited by the internal
resistance or impedance of the circuit breaker (see table I).
Auxiliary contacts:
Contact capacity shall be 10 amperes to 250 volts 60/400 Hz and 2 amperes resistive, 1 ampere inductive to
50 V dc.
Tripping-time delays: See table I and table II.
Terminal and mounting hardware: See figure 1.
Terminals: See figure 1. Solderability is applicable to auxiliary contact terminals.
Actuator strength: 25 pounds.
Actuator operating force: 4 pounds, maximum.
Terminal strength:
Applied load: 30 pounds.
Applied torque: 10 inch-pounds.
Interrupting capacities:
2,000 amperes at 50 V dc.
2,000 amperes at 120 V ac, 60 Hz.
1,500 amperes at 120 V ac, 400 Hz.
1,000 amperes at 240 V ac, 60 and 400 Hz.
Seal: Panel seal test applies.
Part or Identifying Number (PIN): The PIN to be cataloged and stocked by the Government consists of the prefix
M55629/20 and two succeeding code letters as follows: 1/, 2/
M55629/20 E M
Single pole circuit breaker with
panel seal and auxiliary contacts.
Current rating code, see table I.
Voltage, frequency, and time delay
curve code, see tables I and II.
______
1/ Special PINs for equipment manufacturers use only. Equipment manufacturers who do not require the high-inrush
feature or auxiliary contacts in specific production applications may order circuit breakers without these features by
modifying the prefix as follows: M55629/20XX: Replace slash with A for items without auxiliary contacts
(M55629A20XX). Replace slash with B for items without the high-inrush feature (M55629B20XX). Replace slash
with C for items without either the high-inrush feature or auxiliary contacts (M55629C20XX).
2/ Replace slash with D for items requiring configuration 2 (M55629D20XX). Replace slash with E for items requiring
configuration 2 without auxiliary contacts (M55629E20XX). Replace slash with F for items requiring configuration
2 without the high-inrush feature (M55629F20XX). Replace slash with G for items requiring configuration 2
without the high-inrush feature or auxiliary contacts (M55629G20XX).
MIL-PRF-55629/20G
6
When circuit breakers without auxiliary contacts are installed in new equipment, replacement spares should possess
this feature since it is more economic for the DoD to stock one version of this item instead of two. Therefore, stock
numbers should not be requested (or assigned) for this special PIN.
TABLE I. Circuit breaker dash numbers and applicable characteristics (configuration 1).
Current rating Voltage
frequency
and
tripping
time delay
code letter
from table II
Resistance
or
impedance
ohms (max)
Current rating Voltage
frequency
and
tripping
time delay
code letter
from table II
Resistance
or
impedance
ohms (max)
Amperes Code
letter Amperes Code
letter
0.1
0.1
0.1
0.250
0.250
0.250
0.35
0.35
0.35
0.5
0.5
0.5
0.75
0.75
0.75
1.0
1.0
1.0
1.75
1.75
1.75
2.5
2.5
2.5
3.0
3.0
3.0
A
A
A
B
B
B
C
C
C
D
D
D
E
E
E
F
F
F
G
G
G
H
H
H
J
J
J
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
120 at dc
120 at 60 Hz
350 at 400 Hz
21 at dc
23 at 60 Hz
43 at 400 Hz
12 at dc
12 at 60 Hz
30 at 400 Hz
6 at dc
6 at 60 Hz
12 at 400 Hz
3 at dc
3 at 60 Hz
7 at 400 Hz
2 at dc
2 at 60 Hz
4 at 400 Hz
0.9 at dc
0.9 at 60 Hz
2 at 400 Hz
.35 at dc
.35 at 60 Hz
.6 at 400 Hz
.3 at dc
.3 at 60 Hz
.5 at 400 Hz
4.0
4.0
4.0
5.0
5.0
5.0
7.5
7.5
7.5
10.0
10.0
10.0
12.5
12.5
12.5
15.0
15.0
15.0
20.0
20.0
20.0
25.0
25.0
25.0
30.0
30.0
30.0
K
K
K
L
L
L
M
M
M
N
N
N
P
P
P
R
R
R
S
S
S
T
T
T
U
U
U
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
.1 at dc
.1 at 60 Hz
.3 at 400 Hz
.08 at dc
.08 at 60 Hz
.15 at 400 Hz
.035 at dc
.035 at 60 Hz
.11 at 400 Hz
.02 at dc
.02 at 60 Hz
.04 at 400 Hz
.013 at dc
.015 at 60 Hz
.03 at 400 Hz
.01 at dc
.011 at 60 Hz
.02 at 400 Hz
.007 at dc
.007 at 60 Hz
.01 at 400 Hz
.006 at dc
.006 at 60 Hz
.007 at 400 Hz
.005 at dc
.005 at 60 Hz
.006 at 400 Hz
MIL-PRF-55629/20G
7
TABLE II. Circuit breaker dash numbers and applicable characteristics (configuration 2).
Current rating Voltage Resistance Current rating Voltage Resistance
Amperes Code
letter frequency
and
tripping
time delay
code letter
from table II
or
impedance
ohms (max)
Amperes Code
letter frequency
and
tripping
time delay
code letter
from table II
or
impedance
ohms (max)
0.1
0.1
0.1
0.250
0.250
0.250
0.35
0.35
0.35
0.5
0.5
0.5
0.75
0.75
0.75
1.0
1.0
1.0
1.75
1.75
1.75
2.5
2.5
2.5
3.0
3.0
3.0
A
A
A
B
B
B
C
C
C
D
D
D
E
E
E
F
F
F
G
G
G
H
H
H
J
J
J
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
186 at dc
142 at 60 Hz
350 at 400 Hz
26.4 at dc
26.4 at 60 Hz
60 at 400 Hz
13.2 at dc
13.2 at 60 Hz
30 at 400 Hz
6 at dc
6.36 at 60 Hz
13.2 at 400 Hz
3 at dc
3 at 60 Hz
7 at 400 Hz
2 at dc
2 at 60 Hz
4 at 400 Hz
0.9 at dc
0.9 at 60 Hz
2 at 400 Hz
0.35 at dc
0.35 at 60 Hz
0.7 at 400 Hz
0.3 at dc
0.3 at 60 Hz
0.5 at 400 Hz
4.0
4.0
4.0
5.0
5.0
5.0
7.5
7.5
7.5
10.0
10.0
10.0
12.5
12.5
12.5
15.0
15.0
15.0
20.0
20.0
20.0
25.0
25.0
25.0
30.0
30.0
30.0
K
K
K
L
L
L
M
M
M
N
N
N
P
P
P
R
R
R
S
S
S
T
T
T
U
U
U
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
K or L
M or N
P, R, or S
0.113 at dc
0.1 at 60 Hz
0.3 at 400 Hz
0.08 at dc
0.08 at 60 Hz
0.175 at 400 Hz
0.035 at dc
0.035 at 60 Hz
0.11 at 400 Hz
0.02 at dc
0.02 at 60 Hz
0.04 at 400 Hz
0.016 at dc
0.015 at 60 Hz
0.03 at 400 Hz
0.012 at dc
0.011 at 60 Hz
0.02 at 400 Hz
0.0075 at dc
0.007 at 60 Hz
0.01 at 400 Hz
0.006 at dc
0.006 at 60 Hz
0.009 at 400 Hz
0.005 at dc
0.005 at 60 Hz
0.006 at 400 Hz
TABLE III. Operating voltage, frequency, and tripping-time delay (configuration 1). 1/
See footnotes at end of table IV.
MIL-PRF-55629/20G
Time
delay
percent
rated
current
Tripping-time delay at 25C 2C (tripping time in seconds)
50 V dc 240 V ac, 60 Hz 240 V ac, 400 Hz
K L M N P R S
Max Min Max Min Max Min Max Min Max Min Max Min Max Min
no trip no trip no trip no trip no trip no trip no trip
100 one hour one hour one hour one hour one hour one hour one hour
125
150
200
400
600
800
1,000
100
N/A
20
2
1
.6
.29
10
N/A
2.5
.36
.13
Inst
Inst
12
N/A
1.5
.29
.15
.06
.05
.5
N/A
.13
.031
Inst
Inst
Inst
120
N/A
20
2.3
1
.6
.29
10
N/A
3
.3
.13
Inst
Inst
18
N/A
1.6
.3
.17
.09
.043
1 N/A
.16
.04
Inst
Inst
Inst
N/A
60
20
4
.6
.06
.045
N/A
6
2.1
.4
Inst
Inst
Inst
N/A
5.8
2
.35
.125
.05
.036
N/A
.6
.2
.035
Inst
Inst
Inst
N/A
500
160
19
3.5
.5
.043
N/A
60
20
2
.250
.025
Inst
1,800 2/ no trip no trip no trip no trip no trip no trip no trip
8
TABLE IV. Operating voltage, frequency, and tripping-time delay (configuration 1) - Continued. 1/
Tripping-time delay at high and low temperature C (tripping time in seconds) 3/
Time
delay
percent
50 V dc
240 V 60 Hz
240 V 400 Hz
rated K L M N P R S
current -40
Max +85
Min -40
Max +85
Min -40
Max +85
Min -40
Max +85
Min -40
Max +85
Min -40
Max +85
Min -40
Max +85
Min
no trip no trip no trip no trip no trip no trip no trip
100 one hour one hour one hour one hour one hour one hour one hour
125
150
200
400
600
800
500
N/A
100
20
5
2
.5
N/A
.1
Inst
Inst
Inst
100
N/A
10
3
1
.5
.1
N/A
.05
Inst
Inst
Inst
500
N/A
100
20
5
.5
1
N/A
.05
Inst
Inst
Inst
100
N/A
10
3
1
.5
.1
N/A
.05
Inst
Inst
Inst
N/A
500
100
20
5
.5
N/A
.5
.1
Inst
Inst
Inst
N/A
100
10
3
1
.5
N/A
.1
.05
Inst
Inst
Inst
N/A
1500
500
100
5
.5
N/A
5
.5
Inst
Inst
Inst
1/ Circuit breakers shall not trip at 100 percent rated current but must trip at 125 or 150 percent of rated current. Between 100 percent and
125 or 150 percent, they may trip. Instantaneous is defined as less than 15 milliseconds.
2/ Items without the high-inrush feature (for use in production only) are not subject to this requirement. High-inrush test shall be performed
using one alternation which has a peak value of 1800 percent of rated current. 400 Hz and dc delays shall be subjected to a 400 Hz
waveform, 60 Hz delays shall be subjected to a 60 Hz waveform.
3/ High and low test temperature tolerances are 2C.
MIL-PRF-55629/20G
9
TABLE V. Operating voltage, frequency, and tripping-time delay (configuration 2). 1/
Time
delay
percent
rated
current
Tripping-time delay at 25˚C ±2˚C (tripping time in seconds)
50 V dc 240 V ac, 60 Hz 240 V ac, 400 Hz
K L M N P R S
Max Min Max Min Max Min Max Min Max Min Max Min Max Min
no trip no trip no trip no trip no trip no trip no trip
100 one hour one hour one hour one hour one hour one hour one hour
125
150
200
400
600
800
1,000
60
N/A
10
2
1
0.5
0.1
7
N/A
0.6
0.15
Inst
Inst
Inst
6.5
N/A
1.2
0.5
0.25
0.1
Inst
0.5
N/A
0.13
0.031
Inst
Inst
Inst
120
N/A
20
3
2
0.8
0.25
10
N/A
2.2
0.3
Inst
Inst
Inst
12
N/A
3
1
0.3
0.15
0.1
0.7
N/A
0.13
0.03
Inst
Inst
Inst
N/A
70
25
5
2.4
1
0.1
N/A
5
2.1
0.4
Inst
Inst
Inst
N/A
8
1.9
0.4
0.25
0.1
0.05
N/A
0.5
0.15
0.02
Inst
Inst
Inst
N/A
400
150
19
7
0.4
0.043
N/A
40
9.5
1.9
Inst
Inst
Inst
1,800 2/ no trip no trip no trip no trip no trip no trip no trip
See footnotes at end of table VI.
MIL-PRF-55629/20G
10
TABLE VI. Operating voltage, frequency, and tripping-time delay (configuration 2) - Continued. 1/
1
/ Circuit breakers shall not trip at 100 percent rated current but must trip at 125 or 150 percent of rated current. Between 100
percent and 125 or 150 percent, they may trip. Instantaneous is defined as less than 15 milliseconds.
2/ High-inrush test shall be performed using one alternation, which has a peak value of 1,800 percent of rated current. 400 Hz
and dc delays shall be subjected to a 400 Hz waveform, 60 Hz delays shall be subjected to a 60 Hz waveform.
3/ High and low test temperature tolerances are ±2°C.
MIL-PRF-55629/20G
Time
delay
percent
rated
current
Tripping-time delay at high and low temperature ˚C (tripping time in seconds) 3/
50 V dc 240 V ac, 60 Hz 240 V ac, 400 Hz
K L M N P R S
-40˚C
Max +85˚C
Min -40˚C
Max +85˚C
Min -40˚C
Max +85˚C
Min -40˚C
Max +85˚C
Min -40˚C
Max +85˚C
Min -40˚C
Max +85˚C
Min -40˚C
Max +85˚C
Min
no trip no trip no trip no trip no trip no trip no trip
100 one hour one hour one hour one hour one hour one hour one hour
125
150
200
400
600
800
500
N/A
100
20
5
2
5
N/A
0.1
Inst
Inst
Inst
100
N/A
10
3
1
0.5
0.1
N/A
0.05
Inst
Inst
Inst
700
N/A
160
26
13
2.8
1
N/A
0.05
Inst
Inst
Inst
100
N/A
10
3
1
0.5
0.1
N/A
0.05
Inst
Inst
Inst
N/A
600
130
32
26
8.4
N/A
0.5
0.1
Inst
Inst
Inst
N/A
100
10
3
1
0.5
N/A
0.1
0.05
Inst
Inst
Inst
N/A
1500
500
100
24
3
N/A
5
0.5
Inst
Inst
Inst
11
MIL-PRF-55629/20G
12
Circuit breakers covered by this specification replace commercial types as specified in table III providing they have
equivalent current, voltage, frequency, and time delay ratings.
Circuit breakers without either auxiliary contacts or the high-inrush feature should be replaced by equivalently
rated military items with both of these features.
TABLE VII. Supersession and substitution data.
Reference documents. In addition to MIL-PRF-55629, this document references the following:
ASTM-B545 MS25082 NASM3212 NASM35338
SAE-AMS-QQ-N-290
The margins of this specification are marked with vertical lines to indicate where changes from the
previous issue were made. This was done as a convenience only and the Government assumes no
liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to
evaluate the requirements of this document based on the entire content irrespective of the marginal
notations and relationship to the last previous issue.
Custodians: Preparing activity:
Army - CR Army - CR
Navy - EC
Air Force - 85 Agent:
DLA - CC DLA - CC
Review activities: (Project 5925-2010-020)
Army - AV, CR4, MI
Navy - AS, MC, OS, SH
Air Force - 19, 99
NOTE: The activities listed above were interested in this document as of the date of this document.
Since organizations and responsibilities can change, you should verify the currency of the information
above using the ASSIST Online database at https://assist.daps.dla.mil.
Superseding
military PIN Superseded manufacturers
PIN
CAGE 81541 CAGE 74193
M55629/20XX Type APGN-6
UPGN-6
IEGN-6
Type JE1
