Installation manual
Electrical
Power
(Continued)
Grounding
A
machine
must
be
properly
grounded.
It
is
recommended
that
an
insulated
green
wire
ground,
the
same
size
as
the
phase
wire,
be
installed
between
the
branch
circuit
panel
and
the
receptacle.
For
some
small
machines
such
as
terminals,
a
continuous
metallic
conduit
is
adequate
for
grounding.
To
ensure
proper
grounding,
a
licensed
electrician
should
check
the
grounding
and
receptacles
for
conformance
with
the
country
electrical
codes.
For
personnel
safety,
the
ground
must
have
sufficiently
low
impedance
to
limit
the
voltage
to
ground
and
to
operate
the
circuit
protective
devices
if
a phase-to-frame
short
occurs.
For
example,
the
ground
path
shall
not
exceed
1
ohm
for
120-volt, 20-ampere
branch
circuit
devices.
Computer
Room
Emergency
Power-Off
Controls
As
a
safety
precaution,
provide
room
emergency
power-off
controls
for
disconnecting
the
main
service wiring
that
supplies
the
computer
equipment.
Install
these
controls
at
a
convenient
place
for
the
operator
and
next
to
the
main
.
exit
doors
of
the'
room.
Follow
national
and
local
electrical
codes.
Lightning
Protection
1-10
You
should
install
lightning
protection
devices
when:
•
An
over!J.ead
power
service
supplies
the
primary
power
•
The
utility
company
installs
lightning
protectors
on
the
primary
power
source
•
The
area
is
subject
to
electrical
storms
or
equivalent-type
power
surges.
o