19 Mar
2011
19 Mar
'11
2:46 a.m.
Brian Knittel wrote:
I need to know how to determine if the setup needs to
be wye or delta.
Check the power plug or cable. If the equipment has a neutral (not
ground!) lead, it needs wye. Otherwise it needs delta.
That usually means that a four-lead power cable (three phases and
ground) for delta, and five-lead (three phases, neutral, and ground) for
wye. However, some old equipment doesn't have a ground lead, in which
case it is three for delta, four for wye.
If the equipment contains any three-phase synchronous motors, you have
to get the phases in the right sequence; if they are reversed, the
motors run backwards. That can affect blowers, and the spindle motors
of disk drives.