Installation guide

HIGH POWER WALL CONNECTOR
5
SERVICE WIRING - NORTH AMERICA
208V 3-Phase, Wye-Connected
With a wye-connected secondary, any two of the legs can be used to
provide 208V to the High Power Wall Connector. For example, L1 and L2,
or L1 and L3, or L2 and L3. The two used phases must each measure
120V to Neutral.
NOTE: A current carrying Neutral is not required.
120V
120V
NEUTRAL
(NOT USED)
GND
L1
L2
L3 (NOT USED)
208V
CAUTIONS:
The unused leg (L3 in the illustration) must remain open. Do not connect to a Neutral
bar, or to Ground.
The center point of the 3 phases (normally used as Neutral) must be grounded to earth
at only one point. This is usually at the Service Entry Breaker Panel.
240V 3-Phase, delta-connected, with center tap
on one leg
With the delta connection, one leg must be center tapped, and only the
two phases on either side of the center tap can be used. The two used
phases must each measure 120V to Neutral.
Consult the transformer manufacturer’s literature to verify that the single
leg can supply the required power.
NOTE: The High Power Wall Connector’s contactor closes only if it detects
the presence of a Ground wire connected to a Neutral point on the
transformer secondary.
L3 (NOT USED)
L1
L2
GND
NEUTRAL
(NOT USED)
120V
120V
240V
CAUTIONS:
The third line (L3 in the illustration) of the delta is 208V, with respect to neutral, and is
sometimes referred to as a “stinger.” Do not use this third line.
Do not use a 3-phase delta-connected transformer secondary without a center tap on
one leg. No “neutral” point is available for the required ground connection.