In a three wire configuration, an additional neutral point is formed by coupling together {HEAD ~ another set} of {TAIL ~ three resistors} 
In a three wire configuration , an additional neutral point is formed by coupling together { HEAD ~ another set } of { TAIL ~ three resistors }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL