Definition of "uninsulated live parts"

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ntr

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According to UL508A 66.1.2:
A door of an enclosure that gives access to uninsulated live parts operating at 50 volts rms ac or
60V dc or more shall be interlocked with the disconnecting means such that none of the doors can be
opened unless the power is disconnected.

What is considered an "uninsulated live part"? I have a small control panel with only a few small motor starters, all are finger safe (IP20) according to IEC 60529, but I can't find any UL type ratings. Does for example a connection terminal on a contactor like this count as uninsulated live part? https://www.schneider-electric.com/en/product/LC1D09P7
I can't find a clear definition of what is a "uninsulated live part". Ultimate question of course is if we need the interlock.
 
Finger safe is not the same thing as insulated.

If I recall correctly, the section of ul508a that you are quoting from only applies to control panels for industrial machines. You might want to consider the definition of an industrial machine which I think is in the standard and see if your control panel qualifies as a control panel for an industrial machine. If it is not a control panel for an industrial machine then this requirement does not apply.
 
ntr said:
According to UL508A 66.1.2:
A door of an enclosure that gives access to uninsulated live parts operating at 50 volts rms ac or
60V dc or more shall be interlocked with the disconnecting means such that none of the doors can be
opened unless the power is disconnected.

What is considered an "uninsulated live part"? I have a small control panel with only a few small motor starters, all are finger safe (IP20) according to IEC 60529, but I can't find any UL type ratings. Does for example a connection terminal on a contactor like this count as uninsulated live part? https://www.schneider-electric.com/en/product/LC1D09P7
I can't find a clear definition of what is a "uninsulated live part". Ultimate question of course is if we need the interlock.
Click to expand...
Yep. Know the score feel the pain. If you do switchboards the bussbars would not normally be insulated but in their own compartment so not usually accessible. Everything else was, as you say, IP20. Even then, panel had a door interlocked isolator. A challenge for commissioning or fault finding.

We bend over backwards to make things "idiot proof".
My view is is that we shouldn't be employing idiots to work on electrical equipment.
 
Thanks for the feedback, it is for industrial machinery indeed.
I think I've found a guide line in NFPA 79

6.2.1 Protection by Insulation of Live Parts. Live parts pro-
tected by insulation shall be completely covered with insulation
that can only be removed by destruction.
Click to expand...
 
Besoeker said:
Yep. Know the score feel the pain. If you do switchboards the bussbars would not normally be insulated but in their own compartment so not usually accessible. Everything else was, as you say, IP20. Even then, panel had a door interlocked isolator. A challenge for commissioning or fault finding.

We bend over backwards to make things "idiot proof".
My view is is that we shouldn't be employing idiots to work on electrical equipment.
Click to expand...

It tends to be a self-correcting process, but it can be hard on the surviving dependents.
 
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