Case Study

Invertek helps US firm create the perfect pizza

Invertek helps US firm create the perfect pizza


A pizza oven manufacturer was experiencing tripping of its ovens in countries outside the USA by VFDs installed in the ovens which were tripping Ground Fault Detection systems.


The replacement of the drives with Invertek's Optidrive E3 IP20, which has low earth leakage, meant the tripping was stopped. The small frame size was also ideal for the oven systems.

Invertek Drives USA

A US pizza oven manufacturer supplying equipment to significant takeaway retailers globally was experiencing problems in many countries due to the requirements for equipment to be installed with Ground Fault Detection (GFD) or Residual Current Detection (RCD) devices in the mains supply to the ovens.

Regular nuisance tripping problems were occurring at stores in various countries, caused by the AC Variable Frequency Drives (VFD) installed inside the oven. Frequent issues with these devices tripping were causing concern for both the oven manufacturer and its customers, with significant downtime being experienced.

Additionally, in some cases, the RCD protection was also applied to other equipment. Hence all equipment could be affected or shut down by these problems.

The source of the earth leakage currents responsible for causing these devices to trip was traced to the Variable Speed Drive (VSD) installed inside the oven to control the heat and conveyor systems within a range of parameters that ensured the perfectly cooked pizza.

The drives being used had a high earth leakage current that was causing the nuisance tripping. While investigating the cause and looking for solutions, the oven manufacturer also discovered that the drives in use in the oven were being discontinued by the VSD manufacturer.

A reliable alternative solution was needed urgently to restore customer confidence and maintain the high levels of quality expected.

The company turned to Invertek Drives, one of the leaders in VFD design and manufacturing, to find that solution. Invertek selected its Optidrive E3 IP20 with its low earth leakage and small physical frame size.

“The ovens were being exported to countries as far as Australia,” said Wayne Morris, Vice-President of Invertek Drives USA.

“They turned to us as our Optidrive E3 IP20 has a low earth leakage current level, which ensures the ovens do not cause nuisance tripping. Also, the small physical size allows convenient fitting. After intense testing in a variety of environments mirroring those where the ovens would be used, the Optidrive E3 surpassed all expectations.”

An additional advantage to the manufacturer was Invertek’s Optistick for commissioning multiples drives. Parameters can be rapidly copied between multiple drives while a built-in Bluetooth interface allows connection to PCs and in the future, smartphones.

“When you’re installing thousands of drives a year with the same parameters each time, the ability to replicate the set-up and commissioning process in each efficiently and accurately is important. Whether that’s by using the Optistick or one of the 14 basic parameters and application functions already installed in the Optidrive,” added Wayne.

The solution ensured the oven manufacturer could now manufacture and export its products knowing the nuisance tripping of RCDs was a thing of the past.

“Providing a solution to what had become a significant challenge to the manufacturer now ensures they can not only manufacture and export to countries around the world without worrying about local electrical systems, but they are helping create the perfect pizzas as well,” added Wayne.

More details about the Optidrive range can are at