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Electric motor terminal blocks

Feb 10, 2025
2
Are terminal blocks required by IEC in electric motor conduit boxes for connecting main power?
 
Depends on the voltage rating.
For machines over 1000 V, typical connection is to have bus bar drilled for each phase (or polarity, if it's DC).
For connections to lower-voltage devices/equipment, it varies widely. Most reputable manufacturers use terminal blocks for sensors, etc. but perhaps not for actual power connections (208 or 380 V).

Is having dedicated terminations (i.e. blocks or bus work) a good idea? Certainly, as that tends to eliminate some of the guesswork on proper spacing, etc. - and separation between voltage levels, which is also a good idea.
 
I prefer tapcon style connectors for motor connections. They're faster than nut/bolt+tape. They're more vibration resistant than a lug on a tap or bar. They require no special tools.

Con: They're expensive if you're making a lot of connections.
 

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