Emerson FPC Junction Box Installation, Main input junction box electrical connections 4 wire

Installation Instructions

1.3.2Junction Box Installation

Main input (power) and low-voltage (control) junction boxes are available for the Liebert FPC to sim- plify customer connections.

The junction boxes, if used, can either be shipped with the system or can be advance-shipped for installation during the roughing-in stage of new construction.

Liebert supplies flexible, 10-foot-long (3m) conduit with cables for connecting the junction boxes to the unit. The junction boxes should be installed a maximum of 8 ft. (2.4m) from the feeder entrance of the unit.

Liebert recommends centering the junction boxes under a floor tile that is easily removed.

Junction box connections must be installed in compliance with the NEC and all other applicable codes.

! WARNING

Verify that incoming line voltage (power) and low-voltage (control) circuits are de-energized and locked out before installing cables or making any connections in the junction box.

Typical junction box connections are shown in Figure 16 and described in 1.3 - Power and Control Wiring.

Table 6 Main input junction box electrical connections (4 wire)

Junction Box Size
Inches (mm)	Electrical Connections
27 x 14 x 6	400A 3 pole power block with 1/2 -13 studs on 1-3/4" (44mm) centers
(686 x 356 x 152)	750A ground busbar with two sets of 3/8 - 16 studs on 1.75” centers
35 x 22 x 6	750A phase busbars with 1/2 -13 studs on 1-3/4" (44mm) centers
(889 x 559 x 152)	750A ground busbar with two sets of 3/8 -16 studs on 1-3/4" (44mm) centers

Table 7	Main input junction box without transformer electrical connections (5 wire)
Junction Box Size
Inches (mm)		Electrical Connections
	27 x 14 x 6	400A 3 pole power block with 1/2 -13 studs on 1-3/4" (44mm) centers
		750A neutral busbar with two sets of 1/2 -13 studs on 1-3/4" (44mm) centers
(686 x 356 x 152)
		750A ground busbar with two sets of 3/8–16 studs on 1-3/4" (44mm) centers
	35 x 22 x 6	750A phase busbars with 1/2 -13 studs on 1.75” centers
		1500A neutral busbar with two sets of 1/2 -13 studs on 1-3/4" (44mm) centers
(889 x 559 x 152)
		750A ground busbar with two sets of 3/8 - 16 studs on 1-3/4" (44mm) centers

Dimensions are given on the drawings furnished with the unit. Typical dimensions of the junction boxes are as follows:

Table 8 Low-voltage (control) junction box dimensions, typical

Width, inches (mm)		8 (203)
Length, inches (mm)		10 (254)
Height, inches (mm)		4 (102)
Table 9	Main input (power) junction box dimensions, typical
					Input Voltage
	Unit kVa
			208-240V		380-415V	480-600V
15-100 kVA, L x W x H, inches (mm)				27 x 14 x 6 (686 x 356 x (152)
125-150 kVA, L x W x H, inches (mm)			35 x 22 x 6		27 x 14 x 6 (686 x 356 x (152)
			(889 x 559 x 152)
200 kVA, L x W x H, inches (mm)			N/A		27 x 14 x 6 (686 x 356 x (152)
225 kVA, L x W x H, inches (mm)			N/A		35 x 22 x 6	27 x 14 x 6
					(889 x 559 x 152)	(686 x 356 x (152)
300 kVA, L x W x H, inches (mm)			N/A		35 x 22 x 6 (889 x 559 x 152)

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