For more information on this see section Conductor &

Terminations – Application Considerations in the Cooper

Bussmann publication SPD – Selecting Protective Devices on

www.cooperbussmann.com

UL 508A Industrial Control Panels Conductors for

Internal Wiring: Copper conductors only. Conductors are

sized based on either the 60°C or 75°C allowable conductor

ampacities from UL508A, Table 28.1 (following). The 75°C

ampacities can only be used if the termination temperature

ratings at both ends of the conductor are rated 75°C or

60°C/75°C. In addition, the conductor insulation is required

to be 90°C or higher temperature rated even though the

ampacity is based on 60°C or 75°C (UL508A, 29.2.1 &

29.6.1(b)).

HVAC Equipment (UL1995):

The electrical panel is required to be marked with the

is mandated in UL508A is not present in UL1995. If the

control panel for the HVAC equipment is a listed UL508A

panel, then the larger UL508A spacing is required.

Power Distribution Block Application UL 1995

Example

PDB in 480V UL 1995 HVAC Equipment must have spacing of 3/8˝

through air and 1/2˝ over surface. PDBs listed to UL 1953 meet this spacing

as well as most terminal blocks recognized to UL 1059.

UL508A, Table 28.1 (Partial)

Wire size

60ºC (140ºF)

75ºC (167ºF)

AWG

(mm

Copper

Copper

14

(2.1)

15

15

12

(3.3)

20

20

10

(5.3)

30

30

8

(8.4)

40

50

6

(13.3)

55

65

4

(21.2)

70

85

3

(26.7)

85

100

2

(33.6)

95

115

1

(42.4)

110

130

1/0

(53.5)

–

150

2/0

(67.4)

–

175

3/0

(85.0)

–

200

4/0

(107.2)

–

230

250 kcmil

(127)

–

255

300

(152)

–

285

350

(177)

–

310

400

(203)

–

335

500

(253)

–

380

600

(304)

–

420

700

(355)

–

460

750

(380)

–

475

800

(405)

–

490

900

(456)

–

520

1000

(506)

–

545

1250

(633)

–

590

1500

(760)

–

625

1750

(887)

–

650

2000

(1013)

–

665

NOTES

1 For multiple-conductors of the same size (1/0 AWG or larger) at a terminal, the

ampacity is equal to the value in this table for that conductor multiplied by the

number of conductors that the terminal is able to accommodate.

1011

SB-BU09622

Page 22 of 23

Data Sheet 1049

Application Notes