Catalog 1308242
Issued 3-03 (PDF Rev. 11-15)
Potter & Brumfield
W28
series
Push to Reset
Fuseholder-Type
Thermal P
&
B Circuit Breaker
Note: VDE not available on 16A and 20A W28 only.
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.
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.
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. CCC mark compliant, certificate
2004010307135992.
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
Current
Rating
in Amps
0.25
0.50
0.75
1.0
2.0
3.0
4.0
5.0
6.0
7.0
Typical
Resistance
in Ohms
14.0
3.55
2.0
0.89
0.17
0.069
0.043
0.030
0.026
0.017
Current
Rating
in Amps
8.0
9.0
10.0
11.0
12.0
13.0
14.0
15.0
16.0
20.0
Typical
Resistance
in Ohms
0.016
0.014
0.011
0.01
0.009
0.009
0.007
0.007
0.007
0.006
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).
Time vs. Current Trip Curve @ +25°C
1000
900
Load Current As A Percent
Of Breaker Rating
800
700
600
500
400
300
200
100
0
.1
1
10
Time In Seconds
100
1000
(B)
(A)
(A) All 3-20 Amp Models
Overload
Trip Times
Ambient Compensation Chart
(B) All 0.25-2 Amp Models
Overload
Trip Times
1.
40
1.
30
Cor ect on Fact
r i
or
1.
20
1.
10
1.
00
0.
90
0.
80
0.
70
0.
60
–20 –10 0 10 20 30 40 50 60
A m bi
ent Tem per ur I D egr
at e n
ees Cent gr
i ade (
°C)
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.
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.
175
135
To use this chart: Read up from the ambient tem-
perature to the curve, and across to find a correction
factor. Multiply the breaker rating by the correc-
tion 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.
USA: 1-800-522-6752
Canada: 1-905-470-4425
Mexico: 01-800-733-8926
C. America: 52-55-1106-0803
South America: 55-11-2103-6000
Hong Kong: 852-2735-1628
Japan: 81-44-844-8013
UK: 44-8706-080208
110
Revised 11-15
www.te.com
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Dimensions are shown for reference
purposes only. Specifications and avail-
ability subject to change.
Catalog 1308242
Issued 3-03 (PDF Rev. 11-15)
Potter & Brumfield
Ordering Information
1. Designator:
W = Circuit breaker
2. Series Number:
28 = Single Pole Fuseholder Type
3. Circuit Function:
X = Series Trip, Push-to-Reset Button
Typical Part Number
>
W
28
-X
Q
1
A
-5
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)
6. Button Color:
A = Black
7. Amp Rating:
0.25
0.75
0.50
1
B = Red
Consult factory for other bezel colors.
Consult factory for other button colors.
2
3
4
5
6
7
8
9
10
11
12
13
14
16
20
Note: All standard part numbers in this series are RoHS compliant.
Stock Items – Authorized distributors are more likely to stock the following items.
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
Push-to-Reset Type
1.
535 M AX.
( 99)
38.
. M AX.
54
( 716)
13.
.
325 M AX.
( 26)
8.
.
19
( 83)
4.
. M AX.
76
( 31)
19.
I
O
.
37
( 4)
9.
. M AX.
76
( 31)
19.
AM P RATI G
N
.
625 M AX.
( 875)
15.
.
250 x .
032 ( 35 x .
6.
813)
Q U I CO N N ECT TERM I ALS
CK
N
Optional Internal Tooth Push-On Lockwasher
For panels greater than .105 (2.67) thickness
55-025B
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.
Part No. 55-025B.
Recommended Panel Cutouts
.570-.575
(14.478-14.605)
.540-.550
(13.716-13.970)
.970 DIA.
(25.64)
55-025B
INTERNAL TOOTH
PUSH-ON LOCKWASHER
For panels greater than .105” (2.67) thickness
Disclaimer
While TE has made every reasonable effort to ensure the accuracy of the infor-
mation in this document, TE does not guarantee that it is error-free, nor does
TE make any other representation, warranty or guarantee that the information is
accurate, correct, reliable or current.
TE reserves the right to make any adjustments to the information contained
herein at any time without notice. TE 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 TE for the latest dimensions and design specifications.
.625-.635
(15.875-16.129)
.625-.635
(15.875-16.129)
.625-.635
(15.875-16.129)
Revised 11-15
www.te.com
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Dimensions are shown for reference
purposes only. Specifications and avail-
ability subject to change.
USA: 1-800-522-6752
Canada: 1-905-470-4425
Mexico: 01-800-733-8926
C. America: 52-55-1106-0803
South America: 55-11-2103-6000
Hong Kong: 852-2735-1628
111
Japan: 81-44-844-8013
UK: 44-8706-080208