Declare machine with control cabinet as portable without main switch.

janni1977

New User
Location
Germany
Occupation
E-Designer
Hi all,

I am an e-designer from Germany and not 100% familiar with UL508.
My question: May I declare a machine that can be transported with a forklift as portable?
I would waive the requirements for a main switch and install a suitable connection plug.

Thank you in advance for your answers!

Jana
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
There is no requirement in UL508a for a main switch.

There is a requirement for a disconnecting means. For portable equipment a plug is considered an adequate disconnecting means. Keep in mind it will probably need to be HP rated.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
There is no requirement in UL508a for a main switch.

There is a requirement for a disconnecting means. For portable equipment a plug is considered an adequate disconnecting means. Keep in mind it will probably need to be HP rated.
What he said.
Personally I have done complete rock crushing systems that were "portable" by virtue of dragging them around with tractors, they were all done with plug-in connectors (although they also had disconnect switches).

if the "machine" is more than a few HP, I don't like the idea of there being no disconnect, but that is not a rule other than my own. It can be really inconvenient to troubleshoot something if the only way to disconnect it is to unplug it. But that depends on the nature of the machine, and only you know what that is.
 
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