How to test pools
Below is an outline of a method for inspecting and testing low voltage electrical pool installations,
which incorporates a multiple earthed neutral (MEN) system of earthing. The methods comply with
the principles of testing for AS/NZS 3000:2007. At all times, a safe system for performing electrical
work should be in place before testing is undertaken.
Tips for safe testing of existing pool installations
Method
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Visual inspection checklist
Mandatory tests
Equipotential bonding
Presence of voltage on exposed metal work.
Visual inspection checklist
The following items provide a guide on the points to be checked during the visual inspection, in
order to determine that the relevant requirements of AS/NZS 3000:2007 have been satisfied.
Further items for inspection can be found in CL 8.2.2.
General
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Protection against direct contact with live parts, e.g. insulation and enclosure
Protection against indirect contact with exposed conductive parts, e.g. double insulation or
isolation transformers
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Protection against hazardous parts, e.g. enclosure, guarding or screening of flammable
materials, hot surfaces, and parts that may cause physical injury
Protection against spread of fire, e.g. penetration of fire barriers
General condition of the electrical equipment, e.g. signs of damage that could impair safe
operation, disconnection of unused electrical equipment or cables.
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Wiring Systems
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Conductor size, e.g. current-carrying capacity and voltage drop
Identification of cable cores
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Adequate support and fixings
Connections and enclosures
Particular installation conditions, e.g. underground, aerial, emergency systems
Segregation from other services and electrical installations
Protection against external influences, e.g. enclosure
Potential risk of mechanical damage.
Electrical equipment
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Isolation and switching devices for protection against injury from mechanical movement
devices and motors
Isolation and switching devices for protection against thermal effects, e.g. motors, room
heaters, water heaters
Switching devices for particular electrical equipment, e.g. socket-outlets, cooking
appliances
Particular installation conditions, e.g. locations affected by water, explosive atmospheres,
extra-low voltage, high voltage
Compliance with required standards
Protection against external influences, e.g. ambient temperature, external heat sources,
presence of water or high humidity, presence of corrosive substances, solar radiation etc.
Earthing
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MEN connection
Earth electrode
Earthing conductors, e.g. size, identification
Equipotential bonding conductors, e.g. size, identification. The minimum equipotential
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bonding conductor size for a pool area is 4mm², unless the conductor is incorporated in a
multi-core cord supplying electrical equipment that is required to be removed for
maintenance
Connections, joints and terminations
Protection against external influences (as above)
Connection to earthing arrangements for other systems, e.g. generating sets, PV array etc
Creation of earthed situation that may require earthing of additional electrical equipment
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Visual inspection of any other parts relevant to the electrical installation should also be
performed.
Mandatory tests
1.
2.
3.
4.
5.
Continuity of earthing system. Clause 8.3.3 (a)
Insulation resistance. Clause 8.3.3 (b)
Polarity. Clause 8.3.3 (c)
Correct circuit connections. Clause 8.3.3 (d)
Verification of impedance required for automatic disconnection of supply (earth fault-loop
impedance). Clause 8.3.3 (e)
6. Verification of operation of residual current devices. Clause 8.3.3 (f).
NOTE: If the electrical installation fails a test, that test and any preceding tests that may have been
influenced by the fault indicated shall be repeated after the fault has been rectified (Clause 8.3.3).
For specific values of results please consult the quick reference tables.
Equipotential bonding (see clause 5.6.2.6 AS/NZS 3000:2007 Amendment 2)
Confirmation of any equipotential bonding conductor to the pool shell or surround is paramount.
The following sequence should be followed:
1. Ensure supply is isolated
2. Check operation of ohmmeter and set zero Ω with leads connected together
3. Test between each end of equipotential bonding conductor under test (this is all the way back to
the main switchboard). Results should indicate that resistance does not exceed 0.5 Ω. (If trailing
lead is used for this test, take the resistance of the lead into consideration)
4. Repeat steps 1 to 3 for each equipotential bonding conductor, e.g. bonding at metal water pipes
near pool area, swimming pool attachments, swimming pool fixtures etc.
Ultimately, exposing part of the reinforcing may be the only way to check some equipotential
bonding connections and their associated conductors. Any fixed extraneous conductive parts of the
pool structure, including the reinforcing metal of the pool shell and deck, and the concrete slab
within arm’s reach of the pool, shall also be checked as these items are often missed during the
construction phase.
Presence of voltage on exposed metal work
With all supply connected, use a voltmeter to prove the instrument is on a known live source and
as an indication of voltage is present. Using the voltmeter, confirm any exposed metal parts of the
pool installation, e.g. metal subswitchboards, metal water pipes, casing of hot water elements etc,
are not energised by testing between the metal part and an independent earth*.
Results should indicate NO VOLTAGE. These procedures have been developed with reference to
AS/NZS 3000:2007. In some cases a pool installation may be effected using methods that were
acceptable when that part of the electrical installation was originally installed, provided that the
methods satisfy the fundamental safety principals of Part 1 of the Standard. MEA highly
recommends compliance with the current standard and the use of RCDs on all pool-related circuits
as a precautionary measure.
*Note: An ‘independent earth’ is an earth that is completely independent of the electrical
installation. That is an earth that is driven by you for the purposes of testing only. The independent
earth shall be driven no closer than four metres from the point at which you are testing, or any part
of the electrical installation such as the earth electrode.
Disclaimer
Whilst all care has been taken in the preparation of this document, the accuracy, completeness or
currency of the content is not warranted or guaranteed. This document has been published as a
guide only.
No liability
The Electrical Contractors Association, Queensland Industrial Organisation of Employers, takes no
responsibility for, and will not be held liable for, any loss or damage suffered by you, your servants
or agents, arising out of or in connection with the provisions of the document to you or the use of
the document by you, your servants or agents.