“D” Flange (Motor Mounting)

This type of motor mounting is used when the
motor is to be built as part of the machine. The
mounting holes of the flange are not threaded.
The bolts protrude through the flange from the
motor side. Normally “D” flange motors are
supplied without feet since the motor is mounted
directly to the driven machine.

Deviation

Difference between an instantaneous value of a
controlled variable and the desired value of the
controlled variable corresponding to the set
point. Also called error.

Delta-Wye

A term or symbol indicating the primary
connected in delta and the secondary in Wye
when pertaining to a three-phase transformer or
transformer bank.

Delta Voltage System

This system provides three phases and three
wires, three “hot” wires. 240 volt and 480 volt
are the most commonly used delta systems.

Delta (D)

A standard three-phase connection with the
ends of each phase winding connected in series
to form a closed loop with each phase 120
degrees from the other. Sometimes referred to
as 3-wire.