Automatic water pumps are highly popular, because once turned on at the mains, an automatic water pump will turn itself on or off as the water level rises or falls, reducing the need for human intervention.
Automatic pumps are particularly useful because, in many projects, they’re only seen twice in their life, once when they’re installed, and again when they’re eventually replaced. (Perhaps with some minor servicing or inspections in-between).
They can be used as part of a passive system, the pumps will activate automatically when required, making them brilliant for use in basements, sumps, or chambers where the water level isn’t monitored manually.
Automatic pumps are available with different styles of float switches, each suited to different spaces and requirements.
The three main types are:
Below, we’ll go through how each works and where it’s best used.
The diagram below compares a manual pump, with two automatic pumps, one with a pendant float switch, and one with a tube float switch.
Pendant float switch pumps have a paddle-like float attached to them, working in a similar way to a ballcock in a toilet cistern.
The float hangs down beside the pump. As water rises, the float lifts along with it. When the float reaches a certain height, it triggers the pump to switch on and start removing water. Once the level drops, the float lowers again, switching the pump off.
While simple and effective, pendant floats aren’t ideal for tight spaces. They need a clear area around the pump so the float doesn’t snag or catch on anything, which can stop it from working.
This type of switch also doesn’t provide exact on/off levels, it’s more of an approximate activation range.
Tube float switch pumps are designed for narrow or confined spaces, such as sumps or small chambers. These can be used when the on or off position needs to be much lower, and more accurate than a standard pendant float can provide.
An example is the Tsurumi POMA Submersible Automatic Sump Pump.
Instead of a float hanging externally, a small float ball is enclosed inside a vertical tube attached to the pump. As the water rises, the internal float moves upward, switching the pump on. When the water level falls, the float drops and the pump turns off.
Because the float is housed inside the tube, it is less likely to foul or get stuck against chamber walls, which is a big advantage in confined setups. Tube float systems also provide a defined on and off level, so you know exactly when the pump will operate.
Used in similar scenarios to tube float switches, pumps also exist which have a float switch on an arm. These are also designed for similar tight or narrow setups such as a small chamber, and similar in usage to a tube float, with a set off and on level. The arm can be more exposed to snagging on cables etc, but less likely to experience blockages than a tube float, and as such is an incredibly popular choice. In fact, the AMA Drainer 301 Automatic Submersible Water Pump pictured below with an Arm Float Switch, in our FPS Iguazu Sump 635 | Packaged Pump Station is a best seller and firm favourite amongst customers.
Some pumps use a sensor panel built into the side of the pump housing or connected via a separate control unit.
These are used where the water level needs to be controlled more accurately, far more precisely than a float switch allows.
A good example is the APP RS32EA Submersible Puddle Pump, which features a fixed panel that can pump water down to low levels with more accuracy.
Another style of Sensor would be the Tsurumi LSC1.4S Puddle Pump that can be fitted with Sensor Probes, or, even supplied with a control panel for fixed installations in areas such as lift shafts.
See video below of the Tsurumi LSC with Sensor and Extension Probes:
Sensor panels are particularly useful in enclosed spaces or when you need the pump to remove very shallow water levels. Because of the electronics involved, they’re typically more expensive than float switch models, but they offer higher precision and reliability.
Automatic pumps are designed to switch on and off automatically as needed, so selecting the right type of switch for your environment is very important.
If the wrong type is chosen, the pump may not function correctly, for example, a pendant float could snag in a small sump, or, you may require a pump to turn on at a lower level than the float switch allows for.
It’s also worth noting that manual pumps generally pump down to slightly lower levels than automatic ones, but they require supervision. Automatic pumps can usually be installed and left to manage themselves, which is ideal for most long-term setups.
One of the most popular models is the EGO 500 Submersible Puddle Pump as it can be switched between manual and automatic modes. This gives flexibility, you can use it automatically for convenience, or manually if you need to drain right down to the last few millimetres. In automatic mode this pump will pump down to a level of 60mm before switching off. This will help maintain a low water level. If you require the water to pump lower, you could switch it to manual mode where it can pump as low as 10mm.
The AMA Drainer 301 can also be switched between modes, however it is predominantly used as an automatic model.
Automatic pumps can save time, reduce stress, operate sewage systems effectively and make flood prevention systems more reliable. Whether you choose a pendant, tube, or sensor panel switch, the key is matching the right pump to the right environment.
If you’d like more advice on which model suits your setup, our team at FloodandWaterPumps.co.uk are always happy to help.
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