three phase, stinger? 3

[stilnsocal]

I just leased a building, It looked liked it had alot of different types of machinery in it. And Im not to familiar
with single or three phase electrical. But I remember this guy saying something about a stinger reguarding the electrical panel. My question is does the word stinger only apply in three phase power. When I use my multi-tester
on these 240 outlets I get some wierd readings. Not like the normal. Could it be three phase?

 

[geekEE]

I just Googled it and found this:

4 Wire, 3 phase Delta, 120/208 Volts
This type of electric service is sometimes called a wild leg or stinger system because one of the legs is 208-240 volts to neutral while the others are 120 volts to neutral.

 

[waross]

Actually, in most fields, this connection is called a 120/240 volt center tapped delta. Yes there is 208 volts to ground from the wild leg or stinger but this is never utilized. The utilization voltages with this system are 120/240 volts single phase and 240 volts three phase delta. When the single phase load is large and the three phase load is small, typically less than the capacity of the smallest distribution transformer normally used in the system this will often be an open delta. With larger three phase loads, it may be a full delta connection. In some areas it is used to supply a small amount of three phase load combined with a large amount of single phase load.
In some areas it is used to supply a small amount of single phase load combined with a large amount of three phase load.
In some areas it is used to provide a ground connection for a delta system.
The voltage ratios 120/208, 115/199 are 1/1.73 (sqrt. 3)
respectfully

 

[dpc]

geekEE - You need to re-Google. 208/120V and 240/120V three-phase are two entirely different beasts.

I've never heard the term "stinger" applied to a wild-leg delta system, but you can certainly get stung by them.

If you have a 240V outlet, it should measure 240 V across the hot leads, regardless of single-phase or three-phase.

If you have 240V three-phase, it is most likely a 240/120 V three-phase delta, aka a "wild-leg" or "red-leg" delta.

If you have 208/120V three-phase system, it is a wye connected system. You will measure 208V across any two hot legs and 120V from any hot leg to ground.

No offense, but it sounds like you should pay an electrician to check it out, if you really need to know. If you take service directly from a utility, they can tell you what it is.

 

[jraef]

Stinger leg; Wild leg; Red leg; High leg; Orange leg; even "Smoker leg" once (when I asked the electrician, he said it was because if you connect to the wrong leg, some appliances let the magic smoke out!). I've heard all of these terms from electricians around the US describing a 120/240 3 phase 4 wire center tapped delta system as noted by waross above. It's kind of a regional thing, although because a lot of electricians are nomadic, the different names get mixed around in the same region sometimes.

This type of question comes up a lot. Someone should probably write an FAQ on it.

JRaef.com
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