MIL-HDBK-1004/10

l)

Current division between main and stub anodes:

(1)

Area of tank bottom protected by stub anodes (see

Figure 99):

2

2

As = B(r

-r

)

2

1

where

r

= 13 feet (radius of protected segment)

2

r

= 2.5 feet (radius of riser)

1

A

= 3.1416 (169 - 6.25)

s

A

= 3.1416 x 162.75

s

A

= 511.3 ft

s

(2)

Maximum current for stub anodes:

I = 2.0 x 511.3

Is = 1022.6 mA or 1.02 A

s

(3)

Maximum current for tank bowl = 15.2 A.

(4)

Maximum current for main anodes:

I

= 15.2 - 1.02

m

I

= 14.2 A

m

m)

Rectifier voltage rating:

(1) Electrical conductor to main anodes. Wire size No. 2 AWG,

0.159 ohm/1,000 feet (refer to Table 10), estimated length 200 feet:

R

=

200/1000

x

0.159 = 0.032

(2)

Voltage drop in main anode feeder:

E

=

IR

where

I = 14.2 A

R = 0.032 ohm

E = 14.2 x 0.032

E = 0.45 V

(3)

Voltage drop through main anodes:

E = IR

165

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