112
P&B
Dimensions are shown for
reference purposes only.
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Catalog 1308242
Issued 3-03 (PDF Revised 4-07)
Specifications and availability
subject to change.
www.tycoelectronics.com
Technical support:
Refer to inside back cover.
Time vs. Current Trip Curve @ +25°C
Overload Trip Times
100%
135%
200%
300%
400%
500%
600%
No Trip
Trip in 1 hour
4.0 - 40.0 Sec.
1.2 - 12.0 Sec.
0.6 - 5.0 Sec.
0.4 - 2.8 Sec.
0.3 - 1.8 Sec.
.1 1 10 100 1000
Time In Seconds
1000
900
800
700
600
500
400
300
200
100
0
Load Current As A Percent
Of Breaker Rating
10,000
135
Features
• Compact, trip-free, rocker-actuated design.
• 5 to 20 amp ratings.
• Provides circuit protection and power switching in a single unit.
• Available with optional indicator lamp.
• Snaps into the same cutout as many common power switches.
• Various color, marking and termination options.
Electrical Data @ 25°C
Calibration: Will continuously carry 100% of rating.
May trip between 101% and 134%, but must trip at 135% of
rating within one hour at +25°C.
Dielectric Strength: 1,500VAC (60 seconds).
Insulation Resistance: 100 megohms.
Maximum Operating Voltages: 50VDC; 125 or 250VAC, 50/60 Hz. (model
dependent).
Mechanical/Environmental Data
Operating Temperature Range: 0°C to +60°C.
Termination: .250” (6.35mm) quick connects, solder terminals or right
angle PC terminals.
Mounting: Snaps into 1.122 x .531 (28.5 x 13.5) panel cutout.
Approximate Weight: 0.37 oz. (10.5g).
Current Typical Current Typical
Rating Resistance Rating Resistance
in Amps in Ohms in Amps in Ohms
5.0 0.050 10.0 0.025
6.0 0.042 15.0 0.017
7.0 0.036 20.0 0.0125
8.0 0.031
.827
(21.0)
.858
(21.8)
1.260
(32.0)
1.232
(31.3)
.315
(8.0)
.394
(10.0)
.598
(15.2)
.25
(6.35)
.504
(12.8)
.394
(10.0)
.354
(9.0)
TYP. .031
(0.8)
TYP.
1.098
(27.9) 1.311
(33.3)
.079
(2.0)
.118
(3.0)
1.122
(28.5)
.531
(13.5)
SUGGESTED
PANEL CUTOUT
Recommended Panel Cutout
Panel Thickness
W51 series circuit breakers accommodate panel thicknesses
from 0.030 in. to 0.118 in. (0.75 mm - 3.0 mm).
Agency Approvals
W51 series is UL 1077 Recognized as Supplementary Protectors, File
E69543, for Canada and the United States. Approved to VDE
0642/EN60934 (Circuit Breakers for Equipment) License Number
40017023 (for AC loads only). CCC mark compliant, certificate
2004010307123223.
Users should thoroughly review the technical data before selecting a product part
number. It is recommended that users also seek out the pertinent approvals files of
the agencies/laboratories and review them to ensure the product meets the
requirements for a given application.
Outline Dimensions
W51 series
Rocker-Actuated
Thermal Circuit Breaker/Power Switch
With Optional Indicator Lamp
Interrupt Capacity: 1,000 amps in accordance with UL standard 1077.
Resettable Overload Capacity: Ten times rated current.
Switch Endurance Cycling: Typically 6,000 operations at 100% of rating.
Reset Time: 60 seconds.
Typical Resistance vs. Current Rating @ +25°C
Ambient Compensation Table
To use this chart: Divide the breaker
rating by the correction factor to
determine the compensated rating.
Calculate the overloads in terms of
the compensated rating to use the
published trip curve.
Do not use these devices outside
their specified operating temperature
ranges.
Ambient Rating Correction Factor
Temperature
in °C 5-6A Models 7-20A Models
10 .80 .80
20 .90 .90
2 5 1. 0 0 1. 0 0
30 1.10 1.05
40 1.25 1.15
50 1.61 1.25
60 2.15 1.40
113
P&B
Dimensions are shown for
reference purposes only.
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Catalog 1308242
Issued 3-03 (PDF Revised 4-07)
Specifications and availability
subject to change.
www.tycoelectronics.com
Technical support:
Refer to inside back cover.
Terminal Types
Angular Button
Design
Contoured Button
Design
For Contoured
Button Design
(Molded)
For Angular Button Design
(Printed)
Our authorized distributors are more likely to stock the following items for immediate delivery.
Ordering Information
ORDERING NOTE: Some options illustrated below are not listed in the “Ordering Information” chart above. Options denoted by “Special” or “Special Order” in their
descriptions are only offered on a special order basis. Other base and button colors and intermediate amp ratings are also available on a special order
basis. All special order items are subject to extended leadtimes and significant minimum order quantities. Your Tyco Electronics sales engineer must
consult with the factory before providing price and availability information regarding items with these options.
Typical Part No. BBW51-A121B1-5
1. Designator:
W = Circuit breaker
2. Series Number:
51 = Switchable, Single Pole, Rocker-Actuated Thermal Model
3. Terminals:
A = Quick connect .250” (6.35mm) straight C = Printed Circuit - right angle
4. Breaker Style & Base Color:
1 = Angular button design (see drawing below), black base color
B = Countoured button design (see drawing below), black base color
5. Rocker Color:
1 = Amber (translucent)
2 = Red (translucent)
3 = Green (translucent)
4 = White (opaque - for use on non-illuminated models)
5 = Black (opaque - for use on non-illuminated models)
6 = Red (opaque - for use on non-illuminated models)
7 = Gray (opaque - for use on non-illuminated models)
8 = Black (opaque) with red (translucent) indicator (only available on model with contoured button)
9 = Black (opaque) with green (translucent) indicator (only available on model with contoured button)
6. Maximum Operating Voltage (AC):
1 = 125VAC 2 = 250VAC
7. Light:
A = Non-illuminated B = Illuminated
8. Marking option:
0 = No marking 2 = RESET/OFF molded (only available on model with contoured button)
1 = RESET/OFF printed
9. Specify Amp Rating:
5678 101520
Standard –
.250 Quick Connect
Terminal
Standard -
RESET/OFF
Standard -
RESET/OFF
Printed on
Bezel
Standard -
RESET/OFF
Standard -
RESET/OFF
Molded into
bezel
Standard -
No Marking
.374
(9.5)
.393
(10.0)
.205
(5.2)
.25
(6.35)
.393
(10.0)
.25
(6.35)
.157 X .098
(4.0 x 2.5)
.098 X .157
(2.5 x 4.0)
.298
(7.55)
.504
(12.8)
.66
(16.76)
.250
(6.35)
.156
(3.95)
.601
(15.26)
TERMINAL THICKNESS
FOR ALL TYPES
.032
(.81)
Special Order -
Solder
Terminal
Special Order -
Solder
Terminal
Standard –
Right Angle PC
Terminal
Case Styles Marking Options
W51-A121B1-5
W51-A121B1-10
W51-A121B1-15
W51-A121B1-20
W51-A122B1-5
W51-A122B1-10
W51-A122B1-15
W51-A122B1-20
W51-A152A1-5
W51-A152A1-10
W51-A152A1-15
W51-A152A1-20
