ETL 1110-9-10(FR)

5 Jan 91

a)

Anode-to-water resistance = 1.42 ohms from step

5.

b)

1-15:

LW RMFT

RW '

1000 ft

Where:

LW =

The positive wire from the rectifier

to the first splice is 15 ft long.

The power feed then continues on

around the hoop to the opposite

side. The length of this run is

about 43.2 ft but since only half

the current is passing through this

portion, its effective length is

43.2/2 = 21.6 ft.

RMFT =

1.02 ohms (From table 3-6, based on

selecting No. 10 AWG cables)

RW =

(15 ft + 21.6 ft) x 1.02 ohms

1000 ft

RW =

0.037 ohm

c)

Negative circuit and tank-to-water resistance

(RC).

The negative wire is connected to the tank

structure near the rectifier, so its resistance

is negligible. Tank-to-water resistance is also

negligible.

d)

Calculate RT:

RT = 1.42 + 0.037 + 0.00

RT = 1.457 ohms; use 1.5 ohms

This is well below the design requirement.

7)

Calculate the rectifier voltage (VREC) from equation 1-

17:

109

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