Operating instructions

12 Installation
1.2.2 Input Junction Box Installation (If Used)
The input junction box option is available to simplify input connections to the Static Switch. Two
input junction boxes and the associated flexible 10 foot long (3 meters) input cables are provided.
(This option is available only with bottom cable entrance, typically when the unit is located on a
raised floor.)
The junction boxes, if used, can be shipped with the unit or advanced shipped for installation dur-
ing the rough-in stage of construction. Locate the junction boxes a maximum of 8 feet (2.4 meters)
from the planned location of the Static Switch.
Due to a lack of clearance for the cables below the unit, the cables are also shipped loose from the
unit for installation at the site. The input cables connect from the input junction boxes to the
input power lugs inside the Static Switch.
The standard configuration for the input junction boxes and cables is for 3-wire-plus-ground
feeds. If the input neutral is required, special 4-wire-plus-ground input cables and junction boxes
are required. Consult factory for details.
Junction box dimensions are as follows:
The junction box terminal wire size range is:
1.2.3 System Grounding
Equipment grounding—Grounding is primarily for equipment and personnel safety, although
proper grounding also enhances equipment performance.
All input and output power feeds must include an equipment grounding means as required by the
NEC and local codes.
An insulated equipment ground conductor is recommended to run with each input and output
power feed. The equipment ground conductors should be at least the minimum size conductor per
the NEC based on the upstream overcurrent protection device.
If conduit is used as a grounding means, adequate electrical continuity must be maintained at all
conduit connections. The use of isolating bushings with a metal conduit can be a safety hazard
and is not recommended.
4-Wire-Plus-Ground Systems—When 4-wire-plus-ground input feeds are utilized, the input
power sources must be properly grounded. Because the neutral is not switched by the Static
Switch, the neutrals of the two power sources will be solidly interconnected. The NEC prohibits
grounding a power source at more than one point. Connecting the neutrals of two grounded power
sources together effectively grounds each of the sources at more than one point, which allows neu-
tral current to flow on the ground system, defeats ground fault protection, creates a safety hazard,
and violates the NEC. Where possible, the two power sources should be located in close
proximity and a single neutral-to-ground bond made (as shown in Figure 8 or as is typical
with a double-ended substation).
1.2.4 Control Wiring Connections
All external control wiring to/from the Static Switch is optional and consists of relay contacts indi-
cating switch status, modem and remote monitoring connections. Connections are made to termi-
nal blocks located in the monitoring compartment. See Figure 9 for typical relay contact outputs.
Refer to the wiring diagram furnished with the unit.
Switch Size
Length
Inches (mm)
Width
Inches (mm)
Height
Inches (mm)
100 amp 16 (406) 14 (356) 6 (152)
250 to 600 amp 30 (762) 16 (406) 6 (152)
Switch Size Power and Ground Lug Wire Range
100 amp #14 to #2/0 AWG
250 to 600 amp (2) #4 AWG to (2) 500 kcmil