Technical information

c) Motor protector type E: the 140M-C2E-C10 previously chosen on the basis of

the thermal protection is kept.The additional use of fuses or magnetic only

circuit breakers is not required, provided the spacing adapter 140M-C-TE is

used (as is clearly indicated on the label).

1.4 Wye-delta starting

170 540

The wye-delta starters are dealt with special rules and tables and the UL508A in

particular dedicates an entire paragraph to it.

The reference schematic is:

1M line contactor

2M delta

Swye

On the basis of the functioning sequence the functioning conditions of the

individual contactors are specified:

• 1M “closed” when the motor is wye closed,“open” when the motor is running

to full capacity;

• 2M “closed” when the motor is being started,“open” when the motor is running

to full capacity;

• S “closed” when the motor is closed,“open” when the motor is being started.

For each contactor it is possible to define a current value to be opened, called

“break current”, and a current value to be closed, called “make current”.

BRANCH CIRCUIT