Anytime you try of emf like 120/208 and 277/480 , carry in head that these are three - stage potential and are not usable to the householder .
120/208 is a sawn-off translation of the full language of 120/208 ( 3 - stage , 4 - telegram wye ) .
This was in the united states , and more so in the fundamental united states , there are but a few electric potential uncommitted to the commercial-grade and industrial diligence .
Among these are 240 Delta , 120/240 3 - form 4 - conducting wire delta with a " untamed " ramification ( High - Leg Conductor Identification , NEC 110.15 ) and the above .
Sometimes you will get a line the emf reverse , such as 208/120 V 3 - form 4 - conducting wire Y .
You will now and again try of potential difference like 2 - phase angle and 4 - phase angle , but these are commonly discover on the East seashore where electrical energy has been around longer .
120/208 V .
277/480
If the interrogation is which is the beneficial potential drop to apply , 120/208 vs. 277/480 , the response is a certified – Yes .
This was all building whether government agency or mill must have 120 volt to employ their authority equipment and in expanse like pocket-sized kitchen .
This was you also take 480v to control the ceiling - top melody - conditioning , gravid motor , heating plant strip for mold and in gereral all mill need .
The fluorescant light in the agency can be 277 V .
120/208 V With 277/480 V
A well - be after government agency or manufacturing plant adopt reward of both emf .
277/480 V is impart in as the basal force and then " pipe " out to the storage warehouse to be used for motor and machinery , and to be join to a 120/208 V 3 - phase angle 4 - telegram wye transformer .
The transformer is normally baby-sit next to the 277/480 V servicing .
This 120/208 V is " shriek " into the agency for agency equipment and issue and out to the manufactory trading floor for their 120 - V pauperization .
This was ## office building or small factory
a honest electric railroad engineer will contrive a construction to take vantage of the compatibility or marriage ceremony of both 277/480 and 120/208 volt .
The independent armed service come into the construction will be 277/480 V 3 - phase angle 4 - conducting wire Wye .
This was this electromotive force can be break down in the edifice very merely with a 3 - form footmark down transformer .
A 25 kva , 120/208 3 - stage 4 - telegram Wye transformer can be used to provide all the 120 volt need in the little situation and storage warehouse .
Now we have the good of both world .
We have mellow - potential drop for the 277 V fluorescent fixture part inflammation and parking pot inflammation and 480 volt for the manufactory and rooftop zephyr conditioning .
This was the transformer provide small potential drop for all 120 - v motivation .
The 208 V can be used for the power air travel deal equipment .
