Should I upsize the wire on a 250ft run?

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mbrooke said:
If double insulated.
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Most modern 120v appliances are available with 2-prong plugs, when only plastic parts are in contact with users.

The persistent 3-prongs remain refrigerators, microwaves, laundry machines, room air conditioners, range/ovens, and their hood light/vents
 
mbrooke said:
This would give insight that an effective ground fault current path is the primary means by which protection against electrocution is achieved and not ground fault circuit interrupters which are essentially a back-up.
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Yes, and you exercised your right to exceed the NEC's 250.140 minimum standard, by removing touch potential with 3-wire European laundry appliances using 240v light bulbs & controls, which never put frame in same path of current carrying conductors.
 
ramsy said:
Most modern 120v appliances are available with 2-prong plugs, when only plastic parts are in contact with users.

The persistent 3-prongs remain refrigerators, microwaves, laundry machines, room air conditioners, range/ovens, and their hood light/vents
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Right, which technically need an EGC even if a GFCI is present. At least thats what the code indicates.
 
ramsy said:
Yes, and you exercised your right to exceed the NEC's 250.140 minimum standard, by removing touch potential with 3-wire European laundry appliances using 240v light bulbs & controls, which never put frame in same path of current carrying conductors.
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Disconnection time remains relevant regardless of the earthing/grounding arrangement.

I still have the circuit sized such that a fault in the appliance or its branch circuit will promptly open the breaker.
 
ramsy said:
Roger that. Inspectors can red tag 3-prong appliance cords plugged into such GFCI protected outlets missing EGC wiring.

However, there is always exceptions in the National Exceptions Code (NEC).

250.114 Exception: Listed tools, listed appliances, and listed equipment covered in 250.114(2) through (4) shall not be required to be connected to an equipment grounding conductor where protected by a system of double insulation or its equivalent. Double insulated equipment shall be distinctively marked.

That leaves 1 place 3-prong is mandated:
(1) In hazardous (classified) locations (see Articles 500 through 517)]
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Those items typically will not have an EGC pin on their factory included cord either.
 
ptonsparky said:
I’ve thought of this issue in the past when sizing pivot laterals. Basically we size for VD to the pivot point, 1400’. Not any thought/planning goes into how long it takes for a fault to open fuses.
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And we generally don't think about it until we run into a troubleshooting situation and happen to witness long trip times first hand on such installs.

My guess is this is part of reason why newer pivot equipment for some time now has had Class CC fuseholders installed in it where old equipment had class R fuseholders.
 
kwired said:
And we generally don't think about it until we run into a troubleshooting situation and happen to witness long trip times first hand on such installs.

My guess is this is part of reason why newer pivot equipment for some time now has had Class CC fuseholders installed in it where old equipment had class R fuseholders.
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Can you explain the difference between class CC fuses and R fuses?
 
mbrooke said:
Can you explain the difference between class CC fuses and R fuses?
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By class R I'm talking about are the typical RK5 fuses you would see used for general purpose time delay applications.

Class CC are current limiting fuses they are a miniature fuse up to 30 amp, will fit in general use miniature fuse holders but other general use miniature fuses will not fit the CC fuseholder because of rejection feature of the fuseholder.
 
mbrooke said:
Smaller fuse blow faster. I guess that makes sense.
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It is only made in 1/10 to 30 amp ratings, but has different trip curve than a RK5 fuse of same amp rating. Also has different trip curve than other general purpose miniature fuses that are same physical size
 
paulengr said:
GFCIs don’t prevent shocks. They respond after it starts.
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They don't prevent all shocks. One example where they possibly do is with wet location conditions sometimes there is fault conditions that make them trip before a user is subject to possible shock. But if the user is suddenly introduced as the fault path he will be shocked and the GFCI will trip after it starts, presuming enough current flows to initiate trip. ~ 5ma still wakes a person up when it passes through them.
 
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