WARNING: Only a qualified electrician should perform
the installation. The installation must be performed in
accordance with all local electrical codes and ordinances.
Only 3 wires are connected, but care must be taken that the service
transformer secondary connection is definitely known, and the
3 wires from the main circuit breaker panel are connected and
labeled correctly. Figures 2, 3, and 4 show the most common
service transformer secondary wiring formats.
Notice that L1, L2, & Ground are labeled on each diagram. Those
transformer outputs correspond to the same inputs on the HCS-D.
Also, each of the two 3-phase diagrams shows an L3 output, which
is not used. Do not connect all three phases of a 3-phase secondary
to the HCS-D. This is a single-phase device.
The Neutral at the service panel must be connected to Earth
Ground somewhere in the system on any of the three connection
arrangements. Ground-fault protection is not possible unless the
Neutral (center-tap on the service transformer) is connected to an
Earth Ground. If no Ground is provided by the electrical service, a
grounding stake must be driven into the Ground nearby, following
local electrical codes. The grounding stake must be connected to
the ground bar in the main breaker panel, and Neutral connected to
Ground at that point.
WARNING: Local electrical codes must always be
followed when installing the grounding stake.
The following diagrams illustrate the three service transformer
secondary connections most common in North America.
HCS-D User Manual
13