ETL 1110-9-10(FR)

5 Jan 91

There are times when it is advantageous to install anode

horizontally as shown in figure 2-24. For further information,

see paragraphs 10.91 through 10.93 of TM 5-811-7 (reference

10). This configuration is particularly helpful when using

packaged ceramic anodes (figure 2-24) since earth backfill can

be solidly tamped around them. The anodes can be laid on the

bottom of a trench or excavation with compacted backfill. This

often achieves better compaction than when tamping in vertical

holes.

The design is undertaken in the same manner as

described in Section 2-2 and 2-3. The single anode-to-earth

resistance is calculated by using equation 2-11:

(eq 2-11)

Where:

RA

=

Anode-to-electrolyte resistance in ohms.

=

Electrolyte resistivity in ohm-cm.

L

=

Length of anode in ft.

d

=

Diameter of anode in ft.

h

=

Depth of anode in ft.

This equation is used to calculate the resistance

of a single anode-to-earth.

For multiple anode installations, equation 1-11 may be used to

approximate total resistance:

RA

RN '

%

N

CC

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