Technical information

FEEDER AND BRANCH CIRCUITS

2.6 Components accepted with restrictions

The UL 508A standard allows “Industrial Control Equipment” called “Manual Motor

Controllers” certified and marked as “Suitable as Motor Disconnect” as UL 508

switch device.

These switches should generally be protected by fuses against over currents.This

protection however may be provided in the field.

In the machine documentation the installation of an overcurrent protection, fuses

or boxed circuit breaker should however be explicitly required by the final user.

The manufacturer of the machine should indicate both the type and size of the

protection (calculated as per the following paragraph) and the cross-section of the

power conductors of the panel to be installed in the field (see example of wiring

diagram).

194E switch

prot. 23 +8 + 4 <= 35 A

RESPONSIBILITY OF THE FINAL

USER

AWG 8 (50A)

Sect. (1.15x22) + 8 + 4 >=37.3 A

Cond. 1.25 x 22 + 1.25 x 8 + 4 > = 41.5 A

AWG 8 (50A)