I'm a newbie in electronic stuff. Does anyone know what it is and where I can buy this? What do these numbers stand for: P30V, 1200UM, NITK? Thanks in advance.

 

It looks like a 'Polyswitch", a resettable fuse. 30V max, 1.2 Amps.
When cold, it should measure close to a short. Then go high resistance when it get hot due to over current. Once it cools again, it works again.
I do not use fuses now, just polyswitches.

 

Never exceed their voltage rating - they catch fire.
For instance: an amplifier with ±30V supplies must have a 60V polyfuse.

 

Does anyone know what it is and where I can buy this?

As noted above, it is a polyswitch. This is Littlefuse product. Search for “polyswitch” on any of the major parts distributor sites (e.g.: Mouser, Newark, &c.).

What do these numbers stand for: P30V, 1200UM, NITK? Thanks in advance.

30V is the maximum voltage. 1200 is the holding current in 1/100A so, 12.00A. The markings on your device are somewhat different than current production which uses “Unnnn” rather than “nnnnUx”.

The NITK is probably a date code but the datasheet doesn’t include it as a marking.

 

1200 is the holding current in 1/100A so, 12.00A.

Yes, my mistake. Not 1.2A as I stated.

 

Thanks, everyone. I really appreciate it

 

What is the application? And why does the TS believe they need a device that they do not know what it is? If a device has failed then probably some other device also failed and caused excess power dissipation. So the replacement part will probably also fail in a short time. Circuit protection devices seldom fail for no reason.

 

I concur with @dendad these O/L devices open during a fault and automatically re-settable.

 

Does anyone know what it is and where I can buy this?

Why do you think it is faulty? If it is measuring a short, it it probably OK. If it is not close to a short, then it has failed.
Often when these gizmos fail, they will be discoloured showing they have run too hot for too long or were used in a circuit at higher than their rated voltage and gotten damaged.

 

What is the application? And why does the TS believe they need a device that they do not know what it is? If a device has failed then probably some other device also failed and caused excess power dissipation. So the replacement part will probably also fail in a short time. Circuit protection devices seldom fail for no reason.

It's for Flashforge Guider II 3D printer.

 

It's for Flashforge Guider II 3D printer.

It automatically shuts off the heated bed when it exceeds the high-temperature limits.