Cal-OSHA regulation question

  • Hello guys.

    I need some help.

    I recently was hired with a company as their Maintenance Supervisor. Here at this new company, they have some Fanuc robots (specifically M-410iB models) for palletizing. The robot cells are fenced and protected by utilizing the Fanuc supplied "FENCE" interlocks. But the company has this policy that requires anyone (maintenance personnel or operators) that needs to enter the robot cell, to completely SHUTDOWN the main power to the robot controller and lockout the controller while the person is in the cell. This policy must be followed even if the operator needs to go inside the cell for a few seconds to retrieve a fallen box that may have been dropped by the robot. The problem is, that by shutting down the robot controller main power completely, it aborts the running program. Now, when it's restarted, the program that was running has been aborted and the operator must run a homing routine to continue where the process left off. This extends the cycle time of the process.

    At my prior company, I was Maintenance Supervisor/Technician. There I worked as a hands-on supervisor. I worked on several Fanuc material handling robots at that company. We also had fenced cells for the robots (utilizing the Fanuc supplied FENCE interlocks as well). But here, we had all our robot cells designed to allow a person to enter the robot cell. We had lockout switches installed inside the cell that were wired in series with the Fanuc supplied "EMERGENCY STOP" interlocks. This allowed a person (maintenance personnel or operator) to be inside the cell safely ensuring that the robot would never be able to move as long as we had these internal E-Stop switches locked out.

    I tried to explain to our engineering team at this new company that this policy of shutting down the robot controller power is extremely slowing down production by having to unnecessarily shut down power every time someone has to enter the robot cell. I explained that, in my 20 plus years experience with Fanuc robots, I have never come across a company that requires a complete shutdown of power to the controller in order to enter the robot cell.

    My problem is persuading and convincing the Safety Coordinator (who is enforcing this policy) at this new company that this policy is not necessary. His reasoning is that it is OSHA law that requires this policy. He holds that Cal-OSHA requires that "...any machine with moving parts must have the main power locked out when servicing the machine". With that wording, I would agree. But in the event an operator (or maintenance) needs to enter the robot cell to do something process-related, OTHER than service the robot itself, I think is allowable without violating any OSHA regulations.

    My question: Can anyone point me to some source in OSHA law, that will allow us to incorporate the Fanuc EMERGENCY interlocks to safely lock out ALL robot movement and allow a person to enter the robot cell for production related reasons (not servicing the robot)?

    I hope my question makes sense and someone can give me some advice on what to show our Safety Coordinator to convince him. He is the one person that is very adamant about not changing the current policy based on my prior experience alone. His reasoning is based on his understanding of the OSHA law. But, fortunately, he says he's more than willing to reconsider his position if I can show him where OSHA allows for this type of entry in the robot cell.

    Can anyone help at all?

    I truly appreciate your suggestions.


  • I have never heard of, or seen any companies do such a thing. I have engineered and installed many robots over the years, including cali, and worked on many other integrators cells over years and have never seen a policy like this. There is a servo off disconnect as mentioned and is easy to install but pricey. I have also seen some companies use area scanners inside the cell (again tied into the fence circuit) to make sure all parties are out prior to a door closure and a re-start. This is not required by the RIA but I have seen this implemented before.

  • Not sure about the Cal-OSHA reg's. We have a few cells with the area scanners wired to the fence circuit. All of our new cells have Fortress Interlock trapped key systems. One type has a key that is removed from the control panel that unlocks the cell door, then the operator removes a different key from the interlock near the door to carry into the robot cell. The other type has 3 keys at the robot cell door. The operator removes a key to open the door and carries the key into the cell. This switch is also wired into the fence circuit. Anyone entering the cell must carry a key with them at all times.

  • i really like those fortress locks. there is even a model that if the lock is opened from the inside, it cant lock again without the supervisor key. they are a little complicated to wire up, but they are slick. small form factor as well.

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