Motor and Transformer Terminal Blocks

[fifty60]

I know I have read somewhere recently that motor connections should be made in a terminal box, but I can't remember if it was NEC of NFPA 79 or somewhere else. Can anyone offer any insight as to where this rule comes from?

Also, I've bought CE marked transformers in the past and they have always came with terminal blocks as opposed to wire leads. I'm trying a different brand (acme) and they have the CE mark, but no terminal blocks, only wire leads. I need help knowing how or where this is a requirement to have the terminal blocks...

The old Transformer manufacturer (with the terminal blocks) informed me that their transformers are also VDE, so they go through routine and costly inspections similar to UL...so not self certified like CE...this Is probably where the TB's come from.

 

[fifty60]

Still would appreciate some help on figuring out when terminal blocks are absolutely required inside of a transformer...

 

[petersonra]

Still would appreciate some help on figuring out when terminal blocks are absolutely required inside of a transformer...

As best I can tell they are not required at all for US applications. They are a convenience, and maybe a time saver.

 

[Jraef]

If you want to send your equipment to Europe and other IEC conforming countries, you will need to have "finger safe" terminals on everything, or restricted access to them. The transformers with flying leads must either have those leads go to finger safe TBs, or be in an inaccessible part of the control cabinet, ie "potted". The transformers that have the TBs mounted on them just save you the trouble, they are typically used for CPTs and having the TBs on top saves you the panel space for them on the DIN rail, plus it separates the voltages better. If you do your own, you will also need barriers to separate the primary and secondary terminals.