Computations cont'd - ETL-1110-9-10FR0095

ETL 1110-9-10(FR)
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ETL 1110-9-10(FR)

5 Jan 91

(2)

The current requirements for stub anodes

is, therefore;

512 sq ft x 2.5 mA/sq ft = 1280 mA or 1.3 amp

(3)

The total current requirement for the bowl

is 19.0 amp (from step 3).

(4)

The current

for

the

main

anodes

is,

therefore;

19.0

amp - 1.3 amp = 17.7 amp

Select number of stub anodes (NS).

In step 11, five stub anodes were assumed.

Check

the number required from equation 1-2:

Where:

1.3 amp (Current requirement from

previous calculation)

IA =

1 amp/anode current rating per anode

from table 2-4

for 4-ft long by

0.138-in. diameter ceramic rods.

N5 =

1.3

NS =

1.3; use 2 - 4 ft anode rods

The five anodes selected to provide proper

coverage over the bottom are more than sufficient

for the desired anode life.

12) Calculate the stub anodes-to-water resistance (RN).

Find the stub anode resistance from equation 1-13:

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

RN '