Members of the Connect trade union have begun their one-day strike action at the Liebherr Crane factory in Fossa.
The union formally known as the TEEU represents electricians at the plant and its members had been on a work to rule.
In a statement to Radio Kerry, Connect has accused the company of unilaterally altering their members terms and conditions of employment.
Radio Kerry has contacted Liebherr for comment.
It is understood that SIPTU, who have over 400 members at the company, will not pass the picket line during today’s action.
The strike action will continue until 8pm this evening.