- Location
- Illinois
- Occupation
- retired electrician
You said it will increase the fuel consumption if you ground one corner of the delta to the hull...it will not. That has nothing to do with the wiring requirements aboard the vessel.
Open delta?
- Thread starter vm3118
- Start date
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PetrosA
Senior Member
- Location
- Lancaster, Pennsylvania
I guess I, along with achieverelectro have problems understanding corner grounded delta. I've read a number of articles and explanations, but I don't get how one phase can be connected to a ground rod and the whole metal part of the installation and not have potential voltage in it? I can understand how a mid point between phases/legs can be a neutral point and not have current to ground when hooked up, but not the end point of a phase. :head spinning:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Let me see if I can reduce your headspins:
The only reason that grounding any conductor of a system would even attempt to energize nearby earth would be if a different conductor of that system was grounded elsewhere, like by the POCO at the pole.
Since the boat's 440v system is not grounded, or hulled, and it has no neutral point to ground, none of its loads will be connected to the hull, as they're all powered line-to-line, whether they're 1ph or 3ph.
Since any land-based Delta supply also has no neutral to ground, and there's also no neutral point to ground, all the loads will likewise be connected line-to-line, whether they're 1ph or 3ph. Sound familiar yet?
Therefore, intentionally grounding any one conductor will have absolutely no effect on power consumption, fuel waste, or loss of electrical capacity. No normal load cares whether its supply conductors are grounded.
This might be an interesting read: http://forums.mikeholt.com/showpost.php?p=708650&postcount=4
The only reason that grounding any conductor of a system would even attempt to energize nearby earth would be if a different conductor of that system was grounded elsewhere, like by the POCO at the pole.
Since the boat's 440v system is not grounded, or hulled, and it has no neutral point to ground, none of its loads will be connected to the hull, as they're all powered line-to-line, whether they're 1ph or 3ph.
Since any land-based Delta supply also has no neutral to ground, and there's also no neutral point to ground, all the loads will likewise be connected line-to-line, whether they're 1ph or 3ph. Sound familiar yet?
Therefore, intentionally grounding any one conductor will have absolutely no effect on power consumption, fuel waste, or loss of electrical capacity. No normal load cares whether its supply conductors are grounded.
This might be an interesting read: http://forums.mikeholt.com/showpost.php?p=708650&postcount=4
mivey
Senior Member
That's about as plain as you can make it. Very nice.
jpweygandt
Member
For the younger people here, you might not know about this. During the wars, when there was a shortage of copper, three phase motors were often wired by taking one of the motor conductors to the closest building steel. This brought on the large use at that time of grounded three phase services. I have run into this several times in the past. I of course learned early on that this was always a condition to look for. I started in the trade in a city that had a large amount of users of three phase power. This may have been without NEC approval but there was a shortage of copper. Many of these were very large motors. Thus a very large savings.
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