Molded case/thermo-magnetic

[fauxfly]

Hi Guys

I'm in an I-line panel, I see two different kinds of breakers, one is a 480V, 20 Amp molded case breaker, the other one is a 480V, 20 Amp thermo-magnetic breaker. My question is what the heck is the difference. Aren't all breakers goiing to fuction the same...seeing an overcurrent, then opening. Why the different name. Vintage of the breaker ??

Thanks

Steve

 

[jim dungar]

Hi Guys

I'm in an I-line panel, I see two different kinds of breakers, one is a 480V, 20 Amp molded case breaker, the other one is a 480V, 20 Amp thermo-magnetic breaker. My question is what the heck is the difference. Aren't all breakers goiing to fuction the same...seeing an overcurrent, then opening. Why the different name. Vintage of the breaker ??

Thanks

Steve

Does it say 'molded case breaker' or 'molded case switch'?
If the catalog numbers are the same, maybe they are different ages and the label changed.

 

[zog]

Hi Guys

I'm in an I-line panel, I see two different kinds of breakers, one is a 480V, 20 Amp molded case breaker, the other one is a 480V, 20 Amp thermo-magnetic breaker. My question is what the heck is the difference. Aren't all breakers goiing to fuction the same...seeing an overcurrent, then opening. Why the different name. Vintage of the breaker ??

Thanks

Steve

Different trips, the mag means it has different trip elements for overloads and faults. But MCCB is a class of breaker, your thermo mag is also a MCCB.

 

[fauxfly]

Thanks guys

I'm still wondering what the difference could be, Zog could you explain it to me, How can a 20 amp breaker have a different trip fuction than another breaker rated the same amperage.

Steve

 

[jim dungar]

In general, Square D I-Line breakers in the "F" frame (100A max types FA, FH, FC , IF) are only available as thermal-magnetic breakers. There is a magnetic only version available, but its use in an I-Line mounting configuration is extremely limited, especially in recent years. Square D also makes an automatic molded case switch, but again it is not commonly available in I-Line mounting.

My guess is that you simply have two different vintages of breaker labeling.

 

[don_resqcapt19]

...There is a magnetic only version available, but its use in an I-Line mounting configuration is extremely limited, especially in recent years. ...

Jim,
What would that be used for? The only code compliant use of a mag only device that I can think of is when it is used in a listed combination starter.

 

[jim dungar]

Jim,
What would that be used for? The only code compliant use of a mag only device that I can think of is when it is used in a listed combination starter.

You are correct.

Some OEMs will install an I-Line panel interior inside of their equipment. The mag-gard breakers can then feed 'listed' starters. This is not as common an application as it used to be.

About thirty years ago, there were starters made in I-Line enclosures, so you could have an I-Line panel be a 'min-motor control center'.