Figure 6-1. Test Circuits

proceed as follows:

3. To check gate of SCR, connect test light as

shown in figure 6-lb. Touch gate lead to mounting block

Stud Size

Torque (pound-

of SCR. Reverse test light connections and repeat test.

inches)

In one of these tests, test light should light. If test light

does not light in either test, replace SCR.

9 to 10

No. 10-32

12 to 15

1/428

6-15.

REPLACING SCR'S AND DIODE. To replace

65 to 75

1/2-20

defective SCR or diode, proceed as follows:

125 to 150

3/4-16

1. Use deep socket wrench to remove component

1. Visually observe connecting terminals and

from panel. When inserting replacement, apply heat

condition of case. If terminals are broken, or oil is

transfer compound to flange and threads.

present on case, replace capacitor.

Screw component in, applying torque specified:

2. Discharge

capacitor

momentarily

connecting resistor across terminals.

6-16.

TESTING

COMMUTATING

CAPACITOR

(1C). When the commutating capacitor is suspected,

Figure 6-1. Test Circuits

6-4