Electrical Opinion Question
Electrical Opinion Question
(OP)
i work in a commercial building where everything runs off of 208v. if someone asks me if we have 220v, how do i respond?
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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Electrical Opinion Question
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RE: Electrical Opinion Question
RE: Electrical Opinion Question
I would say that most people that ask that question do not have a clue as to what the answer means.
RE: Electrical Opinion Question
RE: Electrical Opinion Question
Alan
----
"It's always fun to do the impossible." - Walt Disney
RE: Electrical Opinion Question
rmw
RE: Electrical Opinion Question
To me, it has always been a gray area. Today, an office person asked what we had that was 220v and I responded the dryers, HVAC, etc. The same question was asked to a peer of mine and he responded "nothing". I think that we were both right in this situation. Technically, there is not 220v, but i think I responded correctly for who/what they were asking. Someone PLEASE tell me i was right
RE: Electrical Opinion Question
208V is a phase to phase connection in the US.
Looks simular to some people, because they are confused.
RE: Electrical Opinion Question
Due to growing demand of electrical heating (in dryers, ranges, water heaters and sometimes house interior heating) a system has been required that allows usage of 120V designed electronics, and is capable of providing more power for the household. For the same reason that the transfer network doesn't work with such a low voltage, the single 120V circuit can only give so much power without the power loss becoming astronomical. There are two methods used to avoid this while keeping compatibility.
240V or split phase: For small residential buildings, the usual method is to rig up a 240V stepdown transformer (instead of 120V) in which the secondary winding is split into two 120V windings (hence the name "split phase"). The center tap is then grounded and fed to the house as if it was the neutral wire of the old 120V system, and each end is wired as a separate 120V live wire. Their waveforms have a half-cycle offset, or 180 degrees, when measured against the neutral wire. The normal 120V designed machinery does not care which live wire you use for them as long as you connect them between a live and neutral wire. Appliances in the home can be distributed on either live wire to maintain balanced loading, and when heating requires high power, the concerned appliance can be connected to both live wires to operate the heating element, providing 240V for it.
208V: For larger residential buildings and blocks especially in big cities, as well as shopping malls etc, there is a system made out of two or three phases. In these cases, one or more of full three phase stepdown transformers are used to feed power to the building. These transformers have three primary windings, each wired between two of the transmission wires, in a triangular fashion. There are also three secondary windings on such a transformer. Normally these are coupled at one end, the center tap is grounded and fed into the house as the neutral wire, while their other ends are fed into the house as separate live wires. Each live wire reads 120V against the neutral point, and between any pair of live wires, you get the reading of 208V. Then, each home in the building is fed with two or three of these live wires as well as the neutral. The rest happens much like on the split phase. Appliances can be distributed on different live wires, and heating elements will be connected between two live wires.
RE: Electrical Opinion Question
RE: Electrical Opinion Question
A 208V, 2-pole circuit (2-wire) derived from a 208Y/120V system is still a single phase circuit.
Whether a circuit is single phase or not has little to do with the source configuration.
Rafiq Bulsara
http://www.srengineersct.com
RE: Electrical Opinion Question