110
Dimensions are shown for
reference purposes only.
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Catalog 1308242
Issued 3-03 (PDF Rev. 2-09)
Specifications and availability
subject to change.
www.tycoelectronics.com
Technical support:
Refer to inside back cover.
W28 series
Push to Reset
Fuseholder-Type
Thermal P&B Circuit Breaker
Note: VDE not available on 16A and 20A W28 only.
Time vs. Current Trip Curve @ +25°C Ambient Compensation Chart
(A)
(B)
(A) All 3-20 Amp Models (B) All 0.25-2 Amp Models
OverloadTrip Times
100%
135%
200%
400%
600%
800%
1000%
No Trip
Trip in 1 hour
2.2-15.0 Sec.
0.55-1.8 Sec.
0.27-0.7 Sec.
0.17-0.45 Sec.
0.12-0.3 Sec.
OverloadTrip Times
100%
175%
200%
400%
600%
No Trip
Trip in 1 hour
4.5-28.0 Sec.
1.0-6.5 Sec.
0.4-4.0 Sec.
1000
900
800
700
600
500
400
300
200
100
0
.1 1 10 100 1000
Load Current As A Percent
Of Breaker Rating
Time In Seconds
175
135
–20 –10 0 10 20 30 40 50 60
1.40
1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
Correction Factor
Ambient Temperature In Degrees Centigrade (°C)
To use this chart: Read up from the ambient
temperature to the curve, and across to find a
correction factor. Multiply 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.
Features
• Push to reset.
• Approved to many international standards.
• Replaces slow blow glass cartridge fuse.
• Labor-saving snap-in mounting.
• Button extends for visual trip indication.
Electrical Data @ 25°C
Calibration: Will continuously carry 100% of rating.
3-20 amp models – may trip between 101% and 134%, but
must trip at 135% of rating within one hour at +25°C.
0.25-2 amp models – may trip between 101% and 174%, but
must trip at 175% of rating within one hour at +25°C.
Dielectric Strength: Over 1,500 volts RMS.
Maximum Operating Voltages: 32VDC; 250VAC, 50/60 Hz.
Interrupt Capacity: 1,000 amps at 250VAC, 50/60 Hz. and 32VDC in
accordance with UL standard 1077.
Mechanical/Environmental Data
Termination: .250” (6.35mm) quick connects. Soldering to terminals is
not recommended.
Mounting: Snaps into panel from front. See Recommended
Panel Cutouts.
Approximate Weight: 0.35 oz. (10g).
Resettable Overload Capacity: Six times rated current for 0.25 through 2
amp models. Ten times rated current for
3 through 20 amp models.
Reset Time: 180 seconds max. for 0.25 through 2 amp models. 5 to 30
seconds for 3 through 20 amp models.
Current Typical Current Typical
Rating Resistance Rating Resistance
in Amps in Ohms in Amps in Ohms
0.25 14.0 8.0 0.016
0.50 3.55 9.0 0.014
0.75 2.0 10.0 0.011
1.0 0.89 11.0 0.01
2.0 0.17 12.0 0.009
3.0 0.069 13.0 0.009
4.0 0.043 14.0 0.007
5.0 0.030 15.0 0.007
6.0 0.026 16.0 0.007
7.0 0.017 20.0 0.006
Agency Approvals
W28 series is UL 1077 Recognized as Supplementary Protectors, File
E69543, and CSA Accepted as Supplementary Protectors (Appliance
Component Protectors), File LR15734. W28 breakers are VDE
approved for use in office equipment (AC loads only) and provides
8mm isolation. 16 amp and 20 amp models do not have VDE
approvals at present.
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 confirm the product meets the
requirements for a given application.
Typical Resistance vs. Current Rating @ +25°C
111
Dimensions are shown for
reference purposes only.
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Catalog 1308242
Issued 3-03 (PDF Rev. 2-09)
Specifications and availability
subject to change.
www.tycoelectronics.com
Technical support:
Refer to inside back cover.
W28-XQ1A-0.25
W28-XQ1A-0.50
W28-XQ1A-0.75
W28-XQ1A-1
W28-XQ1A-2
W28-XQ1A-3
W28-XQ1A-4
W28-XQ1A-5
W28-XQ1A-6
W28-XQ1A-7
W28-XQ1A-8
W28-XQ1A-10
W28-XQ1A-12
W28-XQ1A-15
W28-XQ1A-20
W28-XT1A-10
W28-XT1A-12
Outline Dimensions
.250 x .032 (6.35 x .813)
QUICK CONNECT TERMINALS
.625 MAX.
(15.875)
.37
(9.4)
.325 MAX.
(8.26)
.54 MAX.
(13.716)
1.535 MAX.
(38.99)
.19
(4.83)
.76 MAX.
(19.31)
.76 MAX.
(19.31)
AMP RATING
I
O
.625-.635
(15.875-16.129)
.625-.635
(15.875-16.129)
.625-.635
(15.875-16.129)
.570-.575
(14.478-14.605) .540-.550
(13.716-13.970)
Recommended Panel Cutouts
.970 DIA.
(25.64)
55-025B
INTERNAL TOOTH
PUSH-ON LOCKWASHER
For panels greater than .105” (2.67) thickness
Push-to-Reset Type
Notes: 1. Soldering to terminals is not recommended.
2. Recommended Panel Thickness: Style Q: .032” - .062” (.813 mm - 1.574 mm)
Style T: .075” - .105” (1.905 mm - 2.667
mm)
3. Internal tooth push-on washer available for panel thickness not covered above.
Stock Items – Authorized distributors are more likely to stock the following items.
Ordering Information
Typical Part Number >W 28 -X Q 1 A -5
1. Designator:
W = Circuit breaker
2. Series Number:
28 = Single Pole Fuseholder Type
3. Circuit Function:
X = Series Trip, Push-to-Reset Button
4. Terminal Type and Mounting:
Q = .250” (6.35mm) Quick Connect will mount in .032”-.062” (.813mm – 1.574mm) thick panel.
T = .250” (6.35mm) Quick Connect will mount in .075”-.105” (1.905mm – 2.667mm) thick panel.
For panel thicknesses other than above, order “Q” type and 55-025B Internal Tooth Push-On Lockwasher.
5. Bezel Color:
1 = Black with White Rate Marking 11 = Black with No Rate Marking
2 = Red with Black Rate Marking 21 = Red with No Rate Marking
B = Black with White “Reset” Marked On Bezel (No Rate Marking) Consult factory for other bezel colors.
6. Button Color:
A = Black B = Red
Consult factory for other button colors.
7. Amp Rating:
0.25 0.75 2 4 6 8 10 12 14 20
0.50 1 3 5 7 9 11 13 16
Optional Protective Boot
.750
(19.05)
.550
(13.97)
.630
(16.00)
I
O
.750
(19.05)
.250
(6.35)
.550
(13.97)
.025
(.635)
Clear Silicone Rubber Boot 23-019A
Optional Internal Tooth Push-On Lockwasher
For panels greater than .105 (2.67) thickness 55-025B
Disclaimer
While Tyco Electronics has made every reasonable effort to ensure the accuracy
of the information in this document, Tyco Electronics does not guarantee that it
is error-free, nor does Tyco Electronics make any other representation, warranty
or guarantee that the information is accurate, correct, reliable or current.
Tyco Electronics reserves the right to make any adjustments to the information
contained herein at any time without notice. Tyco Electronics expressly disclaims
all implied warranties regarding the information contained herein, including, but
not limited to, any implied warranties of merchantability or fitness for a particular
purpose.
The dimensions in this catalog are for reference purposes only and are subject to
change without notice. Specifications are subject to change without notice.
Consult Tyco Electronics for the latest dimensions and design specifications.
Note: All standard part numbers in this series are RoHS compliant.