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Many Fire and Rescue Services have struggled with the complexity of engine mounted generator systems on their vehicles. As these generator systems become older, they become more difficult to work. They also become less reliable and less energy efficient. If these generator systems were changed to a battery/inverter system, not only does this increase reliability, it also reduces maintenance costs and downtime considerably.

Euroflo Specialise in the supply of electric submersible pumps which are used on the Fire and Rescue Service vehicles, along with Antares who specialise in the design, manufacture and supply of on-board vehicle power and control products.

Euroflo and Antares working together carried out a series of tests using the Grindex Minex 110v Pump powered by the Antares 24v battery powered inverter systems. These tests proved that sufficient power could be produced to start the Grindex Minex 110v pump underwater, where a number of other pump brands had proven unsuccessful previously. These trials were conducted to find the right equipment with a view to supplying the fire brigade vehicles with a proven quality equipment package.

These tests were completed with the Grindex Minex 2” 110v submersible pump. This pump produces flow rates of 8 l/s and heads of up to 15 metres. The power range of the pump is 0.85 to 1.1 KW (Kilowatt).

The test system was configured with 4 No 66145 Cyclic Duty GEL batteries connected as 24V, giving a capacity of 250Ah, with 1520 CCA (Cold Cranking Amps @ -18˚C)
(Exide heavy duty truck batteries for comparison offer 1400 CCA and 1850 CCA)

Inverter 1 – SD3500 3.5 kW continuous, 4.5kW up to 3 seconds, up to 6kW under 0.2sec
Inverter 2 – SK3000 3.0 kW continuous, 2.45kW up to 3 minutes, 6kW up to 1 second

The 2 inverters are built for different applications, hence the different power ratings. Inverter 2, the SK3000 had now been fitted to in excess of 40 fire vehicles in the last 18 months and about the same volume prior to that, so the install base is currently over 100 units. The SD3500 is more robust and will give the brigades more scope for other equipment.

To work out the potential impact of the pump on a battery set if the engine is not running, or the alternator power is not available then the calculation will be;

For instance,
The pump is capable of 4L per second = 240L per minute
The tank is 1200L = 5 minutes to fill
The pump requires 50A @ 24V to run, plus the start-up current.

Therefore the calculation is: 50A / (5/60) = 4.17Ah + start-up

Start-up is 187A @ 24V for up to 3 seconds, which equates to 0.15Ah (just need the vehicle cranking batteries to be healthy to get the energy out, but flooded and AGM truck batteries are good at delivering this as they’re cranking the engine). Total energy consumed therefore is 4.32Ah.

Given the truck will have about 120Ah batteries this is no issue. If operations get busy and fire engines were operating without the engine running there is minor conflict with other leaching loads that are on the vehicle, such as the data terminal and communication systems which are always on and draining 5A batteries. So there are plenty of reasons for the fire crews to never turn the engine off!

Andy Barber of Antares says “The day was very worthwhile from my perspective given that I had the chance to prove that both our existing 3kW inverter and the latest 3.5kW inverter systems can start the Grindex Minex pump in water and run for prolonged period of time.”

As a result of this trial, Euroflo secured a contract to supply 29 of the latest 2”Grindex Minex 110v pumps model to the vehicle builders for the fire and rescue services. David Sullivan of Euroflo said “It was great to test the new technologies available to broaden the scope for running larger performing pumps through battery powered inverter systems, which opens up further possibilities including solar battery charging”.