Characteristics of the field circuit

E = Rated nominal voltage of excitation circuit;
Ec = Exciter ceiling voltage (Ec = 140%E)
If = Rated nominal current of excitation circuit
Kdc·If = Medium value of the field current under armature circuit fault conditions, at the instant of the contactor's opening;
Kc·If = Peak value of the field current under armature circuit fault conditions at the instant of the contactor's opening;
Iccf = Field current under field circuit fault conditions with voltage = Ec;
Rd = Value of the disharge resistor in ohms.

Characteristics of the contactor

1. Rated nominal voltage Vn›=E
2. Rated continuous current of main contacts In›=1,1 If
3. Rated short-time voltage of main contacts V'›=Ec
4. Rated maximum interrupting voltage of main contacts Vcc›=Kdc·If·Rd+E
5. Rated interrupting current of main contacts at V' (short-circuit in the field circuit) I'cc›=Iccf
6. Rated interrupting current of main contacts at Vcc (short-circuit in the armature circuit) Icc›=Kdc·If+E/Rd
7. Rated 1/2 second short-time current of the main contacts Icc0,5›=Iccf
8. Rated interrupting current of the disharge contacts at V' Iccd›=Ec/Rd
9. Rated making current of the disharge contacts (short-circuit in the armature circuit) Ichd›=Kc·If+Ec/Rd
10. Rated 15 seconds short-time current of the discharge contacts Id15''