Installation in Equipment

Clearances and Minimum Distances

When installing a circuit breaker, minimum distances (clearances) must be maintained between the device and panels, busbars and other protection devices installed nearby. These distances are defined by tests carried out in accordance with UL standards.

If installation is not checked by type tests, it is also necessary to:

use insulated bars for circuit breaker connections.
segregate the busbars using phase barriers.

For PowerPacT B-frame devices, terminal shields and interphase barriers are recommended and may be mandatory depending on type of installation.

PowerPacT B-frame Clearances, UL Standard

For all types of PowerPacT B-frame circuit breakers that use uninsulated power connections (for example, busbars, spreaders, or uninsulated compression lugs), the minimum clearance distance between the enclosure backplate (grounded metal) and uninsulated power connections is shown below.

When using uninsulated connectors be sure to maintain the proper clearance between live parts and the grounded metallic back pan or use the insulation screen.

Minimum Enclosure Dimensions
Standard (80%)	100% Rated
14.6 x 8.5 x 3.16 in. (371 x 216 x 80 mm)	18.13 x 8.63 x 4.13 in. (461 x 219 x 105 mm)

Minimum Clearance Dimensions to Enclosure or Any Grounded Metal
Operating voltage V < 690 Vac, 250 Vdc
For devices equipped with:	Clearance
	Between devices	Between device and sheet metal
		Painted sheet metal			Bare sheet metal
		A1	A2	B	A1	A2	B
No terminal accessories	0	1.18 in. (30 mm)	0.19 in. (5 mm)	0	1.57 in. (40 mm)	0.19 in. (5 mm)	0.19 in. (5 mm)
Interphase barriers	0	0	0	0	0	0	0.19 in. (5 mm)
Long terminal shields	0	0	0	0	0	0	0.19 in. (5 mm)

Minimum Clearances to Bare Busbars
Operating voltage V ≤ 690 Vac, 250 Vdc
Clearances to live bare busbars *
Spacing E ≤ 2.36 in. (60 mm)		Spacing E > 2.36 in. (60 mm)
D1	D2	D1	D2
7.87 in. (200 mm)	3.94 in. (100 mm)	4.72 in. (120 mm)	2.36 in. (60 mm)

Exposed Conductor Clearance

An insulating screen or long terminal shield is required if C < 0.5 in. (< 12.7 mm) if voltage is ≥ 300 Vac.

PowerPacT B-Frame Clearances, IEC Standard

When using uninsulated connectors be sure to maintain the proper clearance between live parts and the grounded metallic back pan or use the insulation screen.

Minimum Enclosure Dimensions

Operating voltage V < 690 Vac
For devices equipped with:	Clearance
	Between devices	Between device and sheet metal
		Painted sheet metal			Bare sheet metal
		A1	A2	B	A1	A2	B
No terminal accessories	0	1.18 in. (30 mm)	0.19 in. (5 mm)	0	1.57 in. (40 mm)	0.19 in. (5 mm)	0.19 in. (5 mm)
Interphase barriers	0	0	0	0	0	0	0.19 in. (5 mm)
Long terminal shields	0	0	0	0	0	0	0.19 in. (5 mm)

Minimum Clearances to Bare Busbars

Operating voltage V ≤ 690 Vac
Clearances to live bare busbars *
Spacing E ≤ 60 mm (2.36 in.)		Spacing E > 60 mm (2.36 in.)
D1	D2	D1	D2
7.87 in. (200 mm)	3.94 in. (100 mm)	4.72 in. (120 mm)	2.36 in. (60 mm)

Exposed Conductor Clearances

An insulating screen or long terminal shield is required if:

two-, three- or four-poles
C < 0.37 in. (< 9.5 mm),

Customer-provided insulation material required if:

one-pole
C < 0.5 in. (< 12.7 mm ).