A 28-year-old was shocked while working at a site on General Bridges Drive.
Paramedics treated and then took him to the Canberra Hospital. He was discharged in the afternoon.
The Construction, Forestry, Mining and Energy Union says the worker was employed by a labour-hire company and was doing demolition work.
CFMEU ACT branch secretary Dean Hall said he would investigate whether the man was properly qualified for the job.
”We have concerns that a person coming through a body hire, or labour hire, company would not have the sufficient experience and qualifications to be performing such a high-risk activity,” Mr Hall said on Thursday.
”We will be making further inquiries because it has raised concerns and it is one of the most dangerous things you can do on a construction site.”
But the Master Builders Association, which represents the construction industry, said there was no doubt the worker had undergone a comprehensive induction, and was suitable for the work.
Association industrial relations director Mike Baldwin said the company involved was well-regarded.
”He wouldn’t be on the tools unless he had that experience, he just wouldn’t,” Mr Baldwin said.
”Particularly in the current environment, where [the media] are jumping at anything, the last thing we want to see is bad headlines.”
The association has also disputed claims that the worker suffered an electric shock.