ETL 1110-9-10(FR)

5 Jan 91

0.0052 *x p x *1n [D/2 AR x DE)]

RN '

(eq 1-13)

LB

rod anode in feet, D is the tank diameter in feet, AR is the

radius of the anode circle in feet, and DE is an equivalent

diameter factor from figure 2-17.

For wire anode circle or hoop (in a water storage tanks):

8DR

2 DR

0.0016 *p*

% 1n

RN '

(1n

)

(eq 1-14)

DR

DA

H

where RA is the anode-to-electrolyte resistance, *p *is the

circle in feet, DA is the diameter of the anode wire in

feet, and H is the depth below the high water level in

feet.

Experience has shown that the diameter of the anode wire

circle (D) should be typically between 40 and 70 percent of

the tank diameter.

anode lead and the rectifier-to-protected-structure lead.

LW RMFT

RW '

(eq 1-15)

100 ft

where LW is the length of wire in thousands of feet and

The structure-to-electrolyte resistance (RC) is dependent

primarily on the condition of the coating.

RS

Rc '

(eq 1-16)

A

13

Integrated Publishing, Inc. |