17
1005494 ISSUE 6
Electrolytic corrosion will occur when dissimilar metals
at are in contact wi each oer create a potential
difference between emselves. Sometimes separated
by a conductive substance known as an electrolyte, e
dissimilar metals will create a small voltage (potential
difference) at allows e ions of one material to pass
to e oer.
Just like a battery, ions will pass from e most positive
material to e more negative material.
Anying more an 0.3 volts can cause e most
positive material to degrade.
A swimming pool wi its associated equipment
can create is effect. The pool water being an ideal
electrolyte and components of e filtration circuit,
heating system, steps, lights etc providing e dissimilar
metals needed to complete e circuit.
Whilst ese small voltages are rarely a safety reat,
ey can create premature failure rough corrosion.
Not dissimilar to corrosion rough oxidation, electrolytic
corrosion can cause complete failure of a metallic
material in a very short period of time.
In order to prevent is type of corrosion all metallic
components in contact wi swimming pool water
should be bonded togeer using 10mm² bonding
cable. This includes non-electrical items such as metal
filters, pump strainer boxes, heat exchangers, steps
and handrails. It is highly recommended at bonding
be retrofitted to existing pools, which may not be
protected by is system.
All electrical work to be carried out in accordance wi
l.E.E. regulations, latest issue, or local codes of practice
as applicable.
The machine should be installed in accordance wi
EMC2004/108/EC.
Always isolate e main power supply before removing
machine covers.
The machine power supply must incorporate e
following. Fuses or motor type circuit breakers (aM
Fuse / MCB type C) to specified rating (see datasheet).
When using a fuse, H.R.C. fuses are recommended. An
isolator which disconnects all poles must be must fitted
wiin 2m and in line of sight of e heat pump. The
isolator must have a minimum of 3mm air gap when
turned off.
All units must be correctly eared/grounded and its
own separate type RCD ear leakage trip installed
which protects e machine only. See data sheet for
e correct type.
The following limits of operation must not be exceeded.
Failure to provide e necessary voltages will invalidate
e warranty. This voltage must be available at e heat
pump whilst running. The voltage must not drop below
e above figures when starting e compressor.
Minimum Maximum
Voltage
Single phase machines 207V 253V
Three-phase machines 360V 440V
Cycle frequency (50Hz) 47.5Hz 52.5Hz
3�6 ELECTROLYTIC CORROSION IN SWIMMING
POOLS
3�7 ELECTRIC WIRING AND SUPPLY