Case Study

Invertek Improve Efficiency At Wesley Group

Invertek Improve Efficiency At Wesley Group


The truck washing system needed 90 amps of starting current and could only operate up to 40 start cycles an hour, restricting the number of vehicles capable of using the system.


The Optidrive Eco was installed to control the pump and immediately reduced the current required by 45 per cent to 50 amps. It could also be used more and with the VFD it meant the amount of water used was reduced when not required for larger vehicles, saving energy and water costs.


Founded in the 1960s, the Wesley Groups product range includes small mobile pressure washers through to large under body chassis washes for commercial vehicles. Their flagship drive-through Wheel Wash cleans dirty trucks as they leave construction sites, landfill sites and quarries. The system switches itself on when it senses a vehicle approaching the ramp and switches itself off when it exits.

Without an inverter, the 22kW pumping system requires 90 amps of starting current and can perform up to forty start cycles an hour (40 vehicles). Even if a 90-amp supply is present on site, a generator may still be needed if its not available at the wheel wash location. The Optidrive Eco overcomes this problem by reducing the current required by the pump at start up by approximately 45% to around 50 amps.

The inverter also controls the output of the pump and is used to reduce the speed of the motor during the summer months, when less water is needed to wash the vehicles. The Optidrive Eco also offers a sleep mode for energy saving and an automatic energy optimiser function for periods of light loads.

Mike West - Wesley Group Managing Director explains; The decision to use the Optidrive Eco was taken purely as a commercial decision. In many cases we would miss sales opportunities for our Wheel Wash if we could not offer it with a reduced start-up current whilst maintaining the full power of the pump unit.

After careful research we selected Invertek distributor, Crawford Controls Ltd. Crawford recommended their IP55 enclosure incorporating an Optidrive Eco, ventilation fan and isolation switch. Due to space restrictions within the pump room, a special runner system was used which allows the whole control box to slide out of the pump house for any maintenance or adjustments.

The introduction to the inverters has gone very smoothly and our customers are reporting improvements in efficiency and also in the cleanliness of the road leading away from the site. Apart from increasing our own sales of wheel washers by offering the machine with a lower power requirement, our customers are also delighted that the UK Government Energy Conservation scheme allows them to claim back the whole cost of the Optidrive.

The innovative and compact Optidrive Eco combines ease of use, simple installation and commissioning with good looks robustness and reliability - making it the lowest cost solution for virtually all variable torque applications between 1.5 160 kW.

The entire product range has a unified control interface and with only 14 standard parameters to adjust, it could not be easier or quicker to use. For the more advanced user the extended parameter set gives access to powerful additional functionality.

The drive also incorporates MODBUS communication with other control equipment as well as through Optistick Smart and OptiTools software.