110
Catalog 1308242
Issued 3-03 (PDF Rev. 11-15)
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.
South America: 55-11-2103-6000
Hong Kong: 852-2735-1628
Japan: 81-44-844-8013
UK: 44-8706-080208
USA: 1-800-522-6752
Canada: 1-905-470-4425
Mexico: 01-800-733-8926
C. America: 52-55-1106-0803
Potter & Brumeld
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
Overload Trip 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.
Overload Trip 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.
900
800
700
600
500
400
300
200
100
0
.1 110 100 1000
Load Current As A Percent
Of Breaker Rating
Time In Seconds
175
135
–20–10 0102030405060
1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
Corre ction Facto r
Am bient Temperature In Degrees Centigra de (°C )
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.
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
notrecommended.
Mounting: Snaps into panel from front. See Recommended
PanelCutouts.
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. 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
