Solar pumps are an ideal way to get water circulating in your pond without having to install a 230 volt mains power point. At first solar may seem like an expensive option but compared to a 230 volt mains system, it can often work out a lot cheaper, depending on the distance you have to run a power cable. While 230 volt pumps are not that expensive, by the time you employ an electrician and install a power cable that has to be buried at least 600mm underground (legal requirement), solar ends up looking very economical. Solar systems provide a safe, economic alternative to running cable and they are very simple to install by the home user. We use commercial grade solar panels that utilise toughened glass encased in aluminium frames.

4 step installation
1. Click the pump into its mounting plate, push on the filter
2. Put the pump in the water
3. Put the solar panel in full sun
4. Plug the two together

Sit back and enjoy.

What is so special about our SXT pumps?

Solar photovoltaic modules (solar panels) are made of special semiconductors that generate electricity from sunlight. The energy that comes from these cells is DC (direct current) - the same type of power you get from batteries. The power that comes from the outlet in your house is AC (alternating current). Without getting too technical, alternating current can be used directly in an electric motor to produce a rotating field. Direct current (DC) can’t. A DC motor has to produce a rotating field by using brushes in conjunction with a commutator to produce the rotation. The problem with brushes is that they wear and when used in a pump that goes for hours at a time they don’t last long. Our SXT DC pumps do not have brushes. Instead they electronically produce a rotating field to turn the pump. The nominal running voltage is 12 volts DC – this can be supplied by a solar photovoltaic module (solar panel), your car’s 12 volt battery, or any other stable 12 volt DC supply. A standard fused plug is supplied with the pump.

Unlike other DC pumps, SXT pumps have been specifically designed to operate from the wide range of voltages that are generated by solar panels. This voltage typically ranges from 2.5 to 17 volts. Normal electric motors can burn out when run on too low a voltage, especially if they are not rotating. Our SXT pumps are also polarity protected, which means that if you wire them up the wrong way they are not damaged (provided the input voltage is not exceeded). The SXT pumps also incorporate very hard ceramic bearings so wear on rotating parts is minimal. Our original pump is still operating in our pond after 10 years.

We also have spare parts for the pumps so if something does go wrong it can be repaired.

All SXT pump kits include:

• 1 SXT solar pump
• 1 holder with suction feet
• 1 fountain head
• 1 filter
• 5 or 10 metre power cable depending on model

Please note.
The pump must always be in water when connected to any power source. The ceramic bearings use water as their lubricant and the motor will quickly burn out if it runs dry. You will void the warranty. If using the optional fountain head that is supplied with the kit, it is very important to make sure that in windy conditions the fountain has all the water falling back into the pond. If it does not, the pond will empty out over time and the pump will burn out. You also need to keep an eye on evaporation and make sure the pond is always topped up.

The table below shows actual pump output at various heads as measured by us. Head is the vertical distance above the water. It is important to use as large an outlet pipe as possible, especially if you are pumping any distance, and to minimise bends in your design. Everything you connect to the outlet of a pump adds resistance and reduces the water flow. We don’t proclaim the volumes to be it to be exact, but they are a fair indication. The pumps were run at 16 volts, which would simulate a panel in full sun. In this case the panels would be a 20 watt for the SXT 500 and a 30 watt for the SXT 2000. Although the SXT 500 and 2000 pump will pump higher than listed in the chart, the volume pumped is not really useful.

1200 litres an hour is a lot of water. When we tested the pump it was emptying our reservoir faster than our garden hose could fill it. 1200 litres per hour equates to a 10 litre paint pail being filled with water in 30 seconds If you want a waterfall, then the SXT 2000 and a 30 watt solar panel is the best option. Tip. To give the illusion of a lot of water going over a waterfall use a flat rock so the water spreads out to a thin sheet, instead of a narrow vee. Do not get too ambitious, as you can see from the table, the higher the waterfall, the lower the pump output.

Solar panel selection

We offer a range of solar photovoltaic modules (solar panels). Solar panels are at their best in full sun. While there could be enough output in dull weather to slowly charge a battery it is not enough to drive a pump. The performance can be improved by having a larger panel on the pump so it will operate in bright cloudy weather for instance. If you are pumping to any sort of head (ie a waterfall) we would recommend a larger panel. Panels of the same type can be put in parallel to increase performance. We only use commercial grade monocrystalline (right) or polycrystalline photovoltaic modules. The cheaper amorphous panels are larger physically, have ordinary glass and their output tends to drop off after about 5 years. Amorphous modules are made for the cheap end of the market.

Solar panels vary in size depending on the brand of panel we are using at the time. However below is a guide as to approximate dimensions.

You can select your pump and then panel depending on the performance you want from the system. You may already have a solar panel, and as long as its output voltage is below 17.5 volts and the wattage is at least that recommended in our table, there is no problem using your own. The specifications of a panel are normally on the back.

FAQs

1. Will my pump operate in rainy weather?
   No. The solar panels need full sun to produce useful output. In summer the pump will still operate in very light cloud, but it will not pump with the same pressure. If using he fountain attachment you will see the fountain rise and fall in time with the clouds moving across the sky.
2. Can I have my pump run at night?
   You can achieve this by running the pump on a 12 volt battery (car battery). It is possible to add a battery to the system so it operates a lot longer, but in order for it to be charged properly the solar panel would have to be 3 times the recommended size. This is because the battery needs to be charged at the same time the pump is operating. The cost of the system would go up dramatically and it would not guarantee 24/7 operation.
3. How safe is the system?
   The maximum voltage is approximately 17 volts, so there is no possibility of electrocution.
4. Instead of purchasing a solar panel can I run the pump on a 12 volt DC power supply?
   Yes you can as long it is stable, can supply at least 2 amps, and does not exceed 17.5 volts DC. You could for instance have the power supply next to a 230 volt mains outlet and then run a low voltage cable to the pump. The low voltage cable does not have to be buried. However you need thicker cable because any voltage drop will affect the performance of the pump. Contact us if you want to do this.
5. Can I increase the distance between the pump and panel?
   Yes you can but as mentioned above any voltage drop will affect performance. However it is better to have a longer cable if this means the solar panel gets more sun.

Click here to display a printable instruction manual (PDF file 1.5Mb)

Solar SXT 500 pump kit $400.00
Postage and packaging NI $9.00 SI $12.00

Solar SXT 2000 pump kit $510.00
Postage and packaging NI $9.00 SI $12.00

20 watt solar panel $210.00
30 watt solar panel $330.00
Postage and packaging NI $9.00 SI $12.00