SPB 100 Circuit Breaker Handle Broken ?

One of the most common repairs we receive with regard to Cutler Hammer Westinghouse SPB circuit breakers is for replacement charging handles.

I would say 90% of the time its not just the operating handle that is broken, but also the SPB hub assembly as well.

You will notice the handle is missing from the right side of this SPB 100 ,  4000 amp circuit breaker. Upon closer inspection you can see that the hub assembly is actually broken as well.

The handle is attached by two screws to the hub assembly. You will need to inspect the area where it attaches to determine if the plastic hub is damaged as well. It almost certainly will need to be replaced.

Why does this happen?

When you charge the circuit breaker manually, you have to pay attention to the charge indicator. The handle is designed to ratchet as you charge the breaker mech springs. What happens is the breaker indicates "charged" but the ratchet may only be half way up on the stroke. Most people think that you need to go all the way to the top of the stroke to complete the charge but in reality it can be charged only a fraction of the way up during the stroke of  the handle. The operator then forces the handle up and breaks either or both the handle and the hub assembly. 

 

SPB Handle 4000 Amp

To prevent this from happening to you, always watch the "Charge" indicator and when it moves from the "open" position and you feel the tightness in the ratcheting mechanism through the handle STOP!  The breaker spring is charged and ready to close.

Of course if you are reading this article it may be too late so call us for a replacement handle and you will only do it once.

SPB Hub Assembly