Electronic Components/Fuse trip breaker


I have a breaker W28-XQ1A-20, how can I, or what do I have to do to trip it so I know it will trip at 20 Amp's
Or is there an official test procedure?
Thank you for your cooperation.

This component appears to be a Tyco thermal circuit breaker.
Because it's thermal, it will have slightly different characteristics depending on such things as ambient air temperature and air flow in the device in which it is installed. If you need something to trip at exactly 20 A, then this is probably not the device to use. But if you can withstand a bit of variation, then it will certainly protect circuits under most conditions. Per manufacturer specitication, Trip Time at 200% = 2.2 to 15 Seconds. This means that you could draw up to 40 amps for up to 15 seconds before the device trips. At 25 amps, it may not trip at all. You can find the specifications for this device here: http://www.te.com/catalog/pn/en/3-1393250-3#features

The easiest way to test a circuit breaker is to attach it to a variable current source. Slowly ramp up the current until the device opens, taking note of that current as you increase it. Remember that the meter will instantly go to zero as soon as the device opens, so you'll need to watch your meter. Because this device is thermal, the trip value will change depending on how quickly you are raising the current.

If you need something that is more accurate, I'd recommend a magnetic breaker.
Telemecanique makes a line of magnetic breakers that may be more suitable to your needs as you'll have much greater control over the actual tripping current. However, they are significantly more expensive than the device you are using. Still, if they interest you, you can find them here: http://www.alliedelec.com/circuit-protection/circuit-breaker/?dsNav=N:4294887064

Electronic Components

All Answers

Answers by Expert:

Ask Experts


Deirdre Hebert


I can answer most questions regarding electronic components, what they are and how to use them.


I worked for a number of years in the electronic component testing industry, designing and building automated test equipment for the electronic manufacturing industry.

Numerous technical manuals for the equipment we built.

UNH, CCAF and others

Past/Present Clients
General Electric, Motorola, Ford, Sensonor and others.

©2016 About.com. All rights reserved.