Waterproofing upsets parking sensors
A new waterproofing gel has been blamed for malfunctions that caused one New Plymouth parking sensor to explode and another to let off a bang.
Following the explosion 440 of the 1600 sensors were turned off as a precautionary measure, the New Plymouth District Council (NPDC) announced on November 25.
In a statement, NPDC chief executive Craig Stevenson said there was a problem with the lithium batteries venting after the sensors were waterproofed.
‘‘This caused pressure to build up inside the sensor,’’ he said, saying there was a ‘‘minor explosion’’.
Garth Mickell, managing director of sensor supplier Arthur D Riley, said there had been no cost to NPDC but he was not able to confirm the exact amount, saying it was ‘‘reasonably substantial’’.
Company staff replaced the batteries in the sensors over six nights and there was also reworking of the software to be done in Wellington. Lithium batteries could fail under certain conditions, Mickell said.
‘‘The particular issue that occurred in New Plymouth [was] we introduced a new way of waterproofing the devices from July this year onwards.
‘‘Basically what it meant was
the device became a pressure vessel. If a battery goes off in that environment it creates a lot of pressure and it goes bang.’’
All sensors had been remedied now, Mickell said, adding the company had responded and dealt with the matter quickly.
‘‘I don’t think there would be an electronic supplier that could say they had not had issues with lithium in one form or another.
‘‘It is about being able to mitigate when they do have an issue.’’
Arthur D Riley supplied one other New Zealand council, where there had not been the same issue but some reworking was done, Mickell said.
It is not the first time New Plymouth has had parking sensor issues.
In 2012, 1600 sensors and 90 pay machines were installed at a cost of $1.2 million. The next year a sensor blew up while a car was parked over it, billowing smoke along the street.
Five years later, 1500 of the onroad sensors were replaced at a cost of $800,000.