Which cable do I need for a well pump?
Many of the well pumps and pump motors we offer come standard with a few meters of 4-core power cable (even for 230V). In most cases, this is not enough, so the cable needs to be extended. While some pumps come with 'factory cable with plug', you can easily extend the supplied cable yourself.
Most professional surface pumps are supplied without cable. You will need to attach a cable yourself, and although this is easier than 'extending', you still need to consider the cable cross-section. You can deviate from the cable type (H07RN-F is not always a strict requirement), but the same logic applies, so you can use our calculator for this as well.
When extending (or installing) power cables, you should keep a few things in mind.
- 1. Use AD8 H07RN-F cable.
- 2. Choose the correct cross-section for your cable.
- 3. Create a solid, waterproof connection.
AD8 H07RN-F cable
AD8 H07RN-F is a high-quality, flexible power cable with a neoprene jacket. Neoprene is tough, UV-resistant, sufficiently oil-resistant, and flame-retardant. A cable with an AD8 classification is suitable for permanent underwater use and is therefore the recommended choice for well pumps.
The correct cross-section
If you don't choose the right cross-section for the desired cable length, the cable can overheat, which is simply dangerous!
To explain it simply:
Think of the cable as a road and the electricity flowing through it as a crowd of cars. If too many cars try to drive on a single-lane road at once, a traffic jam occurs. If the road is very short, that's not a big deal, but if you have to travel a long distance with many cars on a single-lane road, it causes significant resistance, and if it gets too extreme, they might catch fire!
Use our cable cross-section calculator!
Use the calculator and enter the motor voltage and amperage. Specify the desired distance the cable must cover from the motor to the power source (in whole meters), and the calculator will indicate the minimum required cross-section. The calculator will also tell you the maximum cable length (for the recommended cross-section) you can use. Our advice is to choose a thicker cable in borderline cases. The calculator will indicate this with a warning if the difference is less than 10%.
The calculator is a tool. Use common sense. Do not compromise on safety!
Creating a waterproof cable connection
We all know that water and electricity can be a dangerous combination. If you are extending a power cable that is permanently submerged, it must be truly waterproof! You can do this in 2 ways:
- 1. A resin joint kit
- 2. Waterproof heat shrink tubing
A resin joint kit consists of 2 plastic shells filled with a supplied resin. The resin hardens, creating a waterproof and mechanically strong connection. A disadvantage is its size, as it sits next to your riser pipe in the well. Additionally, the resin needs time to harden. The size offers an advantage: it fits WAGO connectors for simple core connection.
Tools needed for resin joint: a fine-toothed saw, sandpaper, and possibly scissors.
Waterproof heat shrink tubing has an adhesive inner layer. The adhesive melts when heated, sealing the cable. Each core gets its own shrink tubing, and we place another waterproof shrink tube over the entire connection for extra protection and a compact finish. A heat shrink connection is much more compact but mechanically less strong. It is quickly applied with a heat gun. A disadvantage is that you must connect the cores by soldering or using a compact crimp connector requiring the correct tool.
Tools needed for heat shrink: a heat gun.
We are often asked: which is better, resin kit or heat shrink? Simply put: both are good! We have no preference. Our advice is to look purely at the practical side and go with your gut feeling. A correctly executed connection is timeless!