Hello,
I'm based in the US but design machines for US and EU market. Can someone tell me what the codes are for wiring an Emergency stop push button. We have some machines in the field, here and in EU that have primary voltage 3ph 240AC wired to the e-stop that act as the main estop for the machine. I thought that it is common practice to run low voltage 24V etc to the e-stop and have that as a control to a relay contactor that would shut off the primary voltage. Is this a rule or can you run primary current to the estop.
Some additional questions.
1. Are you allowed to run more than 120V AC to an operator control? What code / section would not allow this? I have seen OSHA code 1910.217 for power presses that this is not allowed. This machine is not a power press though and doesn't fall under OSHA specific machines. Does NFPA 79 cover this? Any NEC code?
2. The machine is rated for 20A on the mains label. Each leg is pulling 9A under max load though and the contactors on the back of the estop is rated for 10A continuous (Ith) 690V. Is this a violation of any code?
Modifications were made to current machines for CE compliance that has low voltage running through the E-stop but I am concerned about ones in the field in the US and EU.
Thanks
Thanks for your help.
-Bar
I'm based in the US but design machines for US and EU market. Can someone tell me what the codes are for wiring an Emergency stop push button. We have some machines in the field, here and in EU that have primary voltage 3ph 240AC wired to the e-stop that act as the main estop for the machine. I thought that it is common practice to run low voltage 24V etc to the e-stop and have that as a control to a relay contactor that would shut off the primary voltage. Is this a rule or can you run primary current to the estop.
Some additional questions.
1. Are you allowed to run more than 120V AC to an operator control? What code / section would not allow this? I have seen OSHA code 1910.217 for power presses that this is not allowed. This machine is not a power press though and doesn't fall under OSHA specific machines. Does NFPA 79 cover this? Any NEC code?
2. The machine is rated for 20A on the mains label. Each leg is pulling 9A under max load though and the contactors on the back of the estop is rated for 10A continuous (Ith) 690V. Is this a violation of any code?
Modifications were made to current machines for CE compliance that has low voltage running through the E-stop but I am concerned about ones in the field in the US and EU.
Thanks
Thanks for your help.
-Bar