Low Voltage Water Pumps
The pros and cons
using a low voltage pump in your water feature
Most pumps used for garden water features such as fountains and ponds run from the standard
power supply (100 - 127V in the Americas and Japan and 220 - 240 in the rest of the world). As long as the
pumps and wiring are installed correctly and maintained regularly they should be as safe as any other electrical
However, if you are unsure then you can get low voltage pumps that operate from a 24 volt supply, though the
range of sizes available is limited. These low voltage pumps were commonplace when submersible pumps first
came onto the market, and people were very nervous about putting a standard voltage pump into a pool of
water. Apart from any other considerations, they did not want to electrocute their fish that, in many cases,
cost more than the pump!
However, as pump design improved, their excellent safety record gave people more confidence in them, and today
low voltage pumps are very rarely used and available only in a limited range of sizes. Standard voltage pumps
are constructed by flooding the parts of the pump with non-moving parts with a liquid resin that sets and insulates
all of the exposed electrical parts. In a standard voltage magnetic pump, the only moving part is the
impellor that is housed outside the casing that holds the electrical parts of the motor, and so the pump is
Were such pumps not safe, the papers would be filled with tales of electrocutions of people and fish.
Since such tales do not appear, then by definition the pumps must be safe.
It is difficult to see, then, the benefits of using a low voltage pump. If you have such a pump, you also
need a step-down transformer to reduce the voltage to 24 volts. This has to be kept in a dry places such as
your home or a garage. Your pump then has to be sited no more than 50 metres from the transformer, since the
voltage can drop over distances above this to render your pump inefficient.
The low voltage pumps are expensive in comparison to a mains operated pump, and if your home is protected by a
RCD system, then the higher powered cable will not present much of a hazard to you, even if you cut through
it. However, if you are installing a pump in an area where the supply is all at low voltage then the low
voltage pump might be necessary. For example, if you have a low voltage model railway that you are running
round a pond, the low voltage pump can be fed from the supply already there and prevents you from having to run a
high powered cable to the installation.
Another reason for using a low voltage pump would be if there is the likelihood of children playing around the
area. Although they, too, should be protected by an RCD system, you will probably have more peace of mind in
using a low voltage. This might also be true in the event of the pump being installed in a high traffic
The term ‘low voltage pump’ can refer to more than just the 24 volt AC pumps that operate with the same power as
the higher voltage pumps, but also to DC pumps that can be run from standard 12V car batteries or by solar
power. These too are used in garden water features, though many run from the mains supply and use
transformers to drop the voltage and rectify the current to DC.
This type of low voltage is very handy where the volume of water to be moved is small, or only small distances
are involved, and they are very safe for use even where children are playing. Where cost is a consideration,
the DC pumps are generally the least expensive, and where larger volumes of water are involved, or it has to be
raised to higher heights, the full powered pumps come next in the pricing stakes with the 24V low voltage pumps the
The only real benefits of a low voltage pump, then, are where it is possible to accidentally cut into the supply
cable, and the disconnection of the electrical supply by the activation of an RCD system would be extremely
inconvenient. A low voltage pump would also be a viable option where there is already a low power system in
use and there is power to spare to allow the pump to be wired into the circuit.
Other than that, the full power pumps are less expensive, do not lose power if the supply point is some distance
away from the pump and are generally more robust. Although low power pumps are available on the market, then,
they are restricted in use and the availability of the 24V pumps will probably fall off, as that of the lower
powered DC solar pumps will increase.