Bucket for 3 Phase Power?

[JoelTXCive]

I am a civil engineer, not electrical; so forgive my lack of knowledge.

What is a 'bucket for 3 phase power'?

I was a in a bid meeting today with contractors and we were going over plans for some large motorized gates. (The electrical engineer was not at the meeting)

The contractors all wanted to know if we had a bucket for 3-phase.

Are they referring to the transformer up on the electric pole? Or, are they talking about a panel box in a control building/cabinet?

Thank you.

 

[jraef]

For an "SPACE" bucket in MCC, does UL 845 requires to be equip with automatic or manual shutter. Or a cap plugs is suffice to cover the stab opening of vertical bus?

You probably should have started a new thread instead of hijacking one, but this is simple enough to not bother now.

No, you don't need automatic or even manual shutters, a cap meets the requirements of UL-845. But if done live, it does mean sticking your hands into a live work space, so even though now it requires adequate Arc Flash protection PPE to do anything with a live bucket, adding the task of sticking your hands inside is something people are loathe to do. In all the MCCs I specify now, I am always putting in automatic shutters, even if people don't know to ask. It's not adding a lot of cost.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[leur2011]

Thanks jraef,

Our vendor offer indicate that space bucket do not have door interlock such that if there is an accident happen due the reason of accessing the space bucket live parts by opening the shutter will void the warranty of their supplied equipment.

Does the above statement acceptable to UL 845 standard?

 

[jraef]

Our vendor offer indicate that space bucket do not have door interlock such that if there is an accident happen due the reason of accessing the space bucket live parts by opening the shutter will void the warranty of their supplied equipment.

Hmmm... I'm afraid I don't understand the gist of that statement.

A "Space" is not a "bucket" in that there is no frame or stab assembly, it's just a blank door over the empty space, preventing access to it until it needs to be used at some future date. So why would anyone be accessing that space if not to plug in a bucket?

If on the other hand what you are referring to as a "space bucket" is what's called an "empty unit insert" for mounting control devices or other things that do not need connection to the MCC bus, then there must be a solid plate in that unit, which would preclude the ability to access the bus bars; plugs or no plugs, shutters or no shutters. So to me, this might be a semantics issue, you need to get clarity over what exactly you are talking about.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[leur2011]

As per our project specification, it state that “Space” – is a switching assembly locations which are not be equipped with a switching device but shall be developed to accept, with no modifications other than the installation of devices within the compartment door, a switching device suitable for a 19 kW (25 H.P.) induction motor.

Then why is it that if there is an accident happen due the reason of accessing the space bucket live parts by opening the shutter, which has no door interlock as safety requirements the manufacturer responsibility and warranty of the supplied equipment will be void ? Would this be acceptable.

 

[waross]

In a disconnect switch or combination starter installed in an MCC, the door is interlocked with the disconnect switch or breaker so that the switch or breaker must be in the open position before the door may be opened.
It is almost impossible to install a standard interlock between the door and the switch or breaker when the switch or breaker is sitting on a shelf in the distributors warehouse.
The typical interlock is part of a standard bucket. When the bucket is installed, the blank cover must be replaced with a cover suitable for the installed bucket. The interlock that is part of the bucket will latch the door that replaces the blank cover.

Bill
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"Why not the best?"
Jimmy Carter