Breaker Types

[Little Bill]

There is another thread on racking breakers. I didn't want to hijack that one so I'm asking here.

What would be the difference in using racking breaker vs a spring loaded breaker?

I recall having a spring loaded breaker in a plant I worked in that operated a 480V transformer connection the the gear. We were shown how to operate it but no mention of PPE. It always scared me to death when I would have to charge that breaker and set it.

 

[Joethemechanic]

I've always assumed that the spring loaded ones have a stronger spring so the contacts move faster, but I really don't know, I've never had one apart.

 

[jim dungar]

I do not know what a spring loaded breaker is.

A racking breaker is one that uses a racking method to push it onto or pull it off of the bus and load lugs. This racking allows the breaker to be removed relatively quickly especially versus removing cables and bus links. Like everything else, nowadays, PPE requirements for racking breakers have changed over the years and are very customer dictated.

 

[Joethemechanic]

Hmmmmm, that spring may be for an air blast

 

[jim dungar]

Hmmmmm, that spring may be for an air blast

The old vertical lift design?

 

[Joethemechanic]

The old vertical lift design?

I don't know, I thought we had some literature on them, but I can't find it. I've only ever had to deal with them twice and it was a big deal to even get the keys to access the room they were in. I never had anything apart in there. We had an outage of about 750 horsepower of air compressors in the middle of the night, and my friend who was there when they were originally installed came in and showed me how to reset them. They have a handle you have to pump a few times to "charge" them before they can be reset. It kind of feels like you are compressing a big spring

 

[Little Bill]

The one we had, the lever had to be operated 6-8 times until the little window opened up saying it was charged. Then you push the set, or close, button to close the breaker.

 

[don_resqcapt19]

The breakers that you have to charge or cock by operating an external lever a number of times are sometimes called spring loaded breakers, as the charging handle is compressing a spring. When you push the button to close the breaker, the power of the spring is released to force the contacts together. As part of this process the opening spring is charged as the closing spring discharges.

 

[Little Bill]

The breakers that you have to charge or cock by operating an external lever a number of times are sometimes called spring loaded breakers, as the charging handle is compressing a spring. When you push the button to close the breaker, the power of the spring is released to force the contacts together. As part of this process the opening spring is charged as the closing spring discharges.

Yep, just like the one we had.
I'm guessing this type, and the racking type, are so the contact from breaker to bus is quicker than just a handle, which could get stuck. That or moved too slow causing arcing. Is that a good assumption?

 

[Joethemechanic]

I said 3 Hail Marys before I pushed that close button. My buddy thought that was funny

 

[jim dungar]

I don't know, I thought we had some literature on them, but I can't find it. I've only ever had to deal with them twice and it was a big deal to even get the keys to access the room they were in. I never had anything apart in there. We had an outage of about 750 horsepower of air compressors in the middle of the night, and my friend who was there when they were originally installed came in and showed me how to reset them. They have a handle you have to pump a few times to "charge" them before they can be reset. It kind of feels like you are compressing a big spring

That spring charging is on almost every power circuit breaker especially rack in style ines. Electric charging motors and remote open/close buttons are a common options.

 

[jim dungar]

The one we had, the lever had to be operated 6-8 times until the little window opened up saying it was charged. Then you push the set, or close, button to close the breaker.

Were they the iron frame DS style sold by West, Square D, ITE, and Cutler Hammer or ones from Siemens or GE? The DS style had an interior dead front, while you could often see the springs and contacts with the other manufacturers.
In the late 90s manufacturer started moving towards the Insulated Case style shown in post #8.

 

[Jraef]

That spring charging is on almost every power circuit breaker especially rack in style ines. Electric charging motors and remote open/close buttons are a common options.

Right. “Power Breakers” all now use a spring charged mechanism to operate them. That has no bearing on whether it is a racking type. Racking is a feature of SwitchGEAR, as opposed to being a SwitchBOARD. There are different design standards for the GEAR, but usually (especially now) the breakers are the same.

In Switchgear, each breaker has an individual cell (cubicle) that is barriered from others so that if the breaker is damaged by interrupting a fault, the collateral damage is contained in that cell and does not take down the entire facility. Plus you can rack out an individual breaker and remove it without having to kill line power to the lineup. But Switchgear is much more expensive and requires a lot more real estate, including rear access.

Switchboards don’t have individual cells to isolate the breakers, so present a higher risk of collateral damage and therefore potentially longer down time if there is a failure. You also can’t (safely) remove them without powering down the entire switchboard, which means down time even to perform routine maintenance.

 

[Little Bill]

Were they the iron frame DS style sold by West, Square D, ITE, and Cutler Hammer or ones from Siemens or GE? The DS style had an interior dead front, while you could often see the springs and contacts with the other manufacturers.
In the late 90s manufacturer started moving towards the Insulated Case style shown in post #8.

Pretty much the same as post #8 but this would have been mid to late 90's.

 

[don_resqcapt19]

Yep, just like the one we had.
I'm guessing this type, and the racking type, are so the contact from breaker to bus is quicker than just a handle, which could get stuck. That or moved too slow causing arcing. Is that a good assumption?

The only thing I associate racking with is the insertion and removal of a breaker in switch gear. That operation connects or disconnects the breaker from the line and load bus connections in the gear. This is what Jim said in post #3.