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ETL 1110-9-10(FR)
5 Jan 91
d = 0.0115 ft
L/d =
4
= 348
0.0115
In this case L/d is greater than 100, 50 no fringe
factor correction is required.
13) Determine total resistance of main and stub anodes
(RT) from equation 1-3:
RT = RN + RW + RC
Where:
RN =
Anode-to-water resistance.
RW =
Header cable/wire resistance.
RC =
Tank-to-water resistances.
a)
Main anode rods:
RN
= 1.33 ohms (from step 10)
RW
= 0.13 ohm
Header cable/wire resistance is calculated from
equation 1-15:
LW RMFT
RW '
1000 ft
Where:
LW
=
200 ft (After reviewing figure 2-20,
it is estimated that 200 ft of wire
will be required to connect the
rectifier to the anode distribution
wiring at the top of the tank)
RMFT
=
0.640 ohm (Wire resistance per 1000
lin ft of No. 8 AWG HMWPE insulated
wire)
= 0.13 ohm
RW
=
200 ft x 0.640 ohm
1000 ft
95
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