Electrical Sàfety
97
problem is the patented Uno earthed heater. To quote the mahu- _”
facturers, ‘In the event of the glass tube breaking or filling up with
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water, the fuse will blow, thus rendering the tank electrically safe’.
(See also Appendix H).
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Mains supply
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Mains supply
., Lamp5\.
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Heater
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Thermostat
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‘(a)
“”
Fig. 39. (a) Series and (b) parallel electrical connections commonly met with in —
the aquarium. The arrows represent current flow
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Two electrical terms with which the aquarist may meet are
and ‘parallel’, which are used to describe connection congurations
_
(see Figure 39). For instance, if a thermostat and heater are con—
nected together as \in (a) they are said to be in series with each other
because the current has to flow through the thermostat to get to the
heater. In aparallel connection, such as where two lamps use the same
supply (Figure 39b), the current flows through each one independçntly pf the other, and one can
without affecting
other. These terms are important becaus\e they often appear
in elec—°
trical instructions and so the aquarist should understand them.
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