110
Dimensions are shown for
reference purposes only.
Dimensions are in inches over
(millimeters) unless otherwise
specified.
Catalog 1308242
Issued 3-03 (PDF Rev. 10-10)
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
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.
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 temper-
ature to the curve, and across to find a correction fac-
tor. Multiply the breaker rating by the correction fac-
tor 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).
R
esettable 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
s
econds for 3 through 20 amp models.
C
urrent Typical Current Typical
Rating Resistance Rating Resistance
i
n 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
W
28 series is UL 1077 Recognized as Supplementary Protectors, File
E
69543, 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
