ETL 1110-9-10(FR)

5 Jan 91

Thus, the copper cored anode longitudinal

resistance

is less than

10 percent of the

anode-to-water resistance (0.048 ohm/1.13 ohm -

0.043 = 4.3 percent) making this an acceptable

riser anode design.

c)

Tank-to-water

and

negative

circuit resistance = 0.0 ohm.

d)

Calculate total resistance of the riser circuit

(RT):

RT = 1.13 + 0.15 + 0.0

RT = 1.28 ohms for riser anode.

17) Calculate the rectifier voltage (VREC) and current:

a)

First, determine the voltage requirement (E) for

each circuit using Ohm's Law:

E = I RT

Where:

I=

Current requirement.

RT =

Total circuit resistance.

Main Anodes:

I = 17.7 amp (from step 11c).

RT = 1.46 ohms (from step 13b).

E = 17.7

x 1.46 = 25.8 V

Stub Anodes:

I=

1.3 amp (from step 11c).

RT =

21.16 ohms (from step 13c).

E = 1.3 x 21.16 = 27.5 V

Riser Anodes:

I=

14.5 amp (from step 4)

RT =

1.28 ohms (from step 16d)

E = 14.5 x 1.28 = 18.6 V

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