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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:
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