factoryrat
Member
I need some of this forums expert advice. Rather than reposting a lot of information please see my initial post of “ArmorStart Controller can release brake with no voltage on motor” from February 13th, 2014, 07:45 AM.
Since that posting our Plant has chosen to continue to use the ArmorStart284G VFD to control the Hoist Motor. The reasoning is the Hoist is in an enclosed work Cell and plant policy states no people should be in Cell when Hoist is operational (lifting and lowering car bodies). Therefore, in their opinion, there is no threat to human life and it is not a safety issue.
I do not want to see the Lift fall again because it will cause lost production, damage equipment, and who knows maybe something breaks and sends a projectile flying that may cause an injury. While the chances of the Hoist falling again are slim, it did happen once, I’d like to prevent it from happening again. I know the current setup is flawed (the plant does not want to spend the money to install proper VFD) and I want to make it better if possible. The Lift / Hoist Motor is wired using cords with Quick Disconnects for the Motor power connection instead of hard-wiring. This quick and easy connection and disconnection of components is a selling feature in ArmorStart advertising. Quick and easy initial installment, replacement of cables and components is fast and easy - all reduces cost.
See attached pictures showing two locations where Motor cable can be easily disconnected. I was wondering if there is some kind of interlock that can be incorporated into the existing setup that would make it impossible to release brake when power to the Lift’s Motor has been disconnected. Also I was thinking /wondering if there might be some kind of a sleeve that could be secured or locked over the cable connection points to prevent cables from being easily unscrewed and disconnected? Has anyone ever see such Safety add-ons?
Black cable is Motor Power and yellow cord is Brake Power. This pic is at VFD.
Lift Motor power can be easily disconnected on floor level at VFD.
Picture of Lift Motor and motor pecker head.
In the last picture this is how the cable was disconnected when I lowered Hoist and it fell. This was the Backup Drive and it was not being used at the time. From the HMI the Backup Drive was accidently selected (an easy to do fat finger). When I selected “Lower Hoist” the brake released and with no power and therefore no torque on Motor the Lift fell to the ground. You can see the Main Drive in the background.
thank you
Since that posting our Plant has chosen to continue to use the ArmorStart284G VFD to control the Hoist Motor. The reasoning is the Hoist is in an enclosed work Cell and plant policy states no people should be in Cell when Hoist is operational (lifting and lowering car bodies). Therefore, in their opinion, there is no threat to human life and it is not a safety issue.
I do not want to see the Lift fall again because it will cause lost production, damage equipment, and who knows maybe something breaks and sends a projectile flying that may cause an injury. While the chances of the Hoist falling again are slim, it did happen once, I’d like to prevent it from happening again. I know the current setup is flawed (the plant does not want to spend the money to install proper VFD) and I want to make it better if possible. The Lift / Hoist Motor is wired using cords with Quick Disconnects for the Motor power connection instead of hard-wiring. This quick and easy connection and disconnection of components is a selling feature in ArmorStart advertising. Quick and easy initial installment, replacement of cables and components is fast and easy - all reduces cost.
See attached pictures showing two locations where Motor cable can be easily disconnected. I was wondering if there is some kind of interlock that can be incorporated into the existing setup that would make it impossible to release brake when power to the Lift’s Motor has been disconnected. Also I was thinking /wondering if there might be some kind of a sleeve that could be secured or locked over the cable connection points to prevent cables from being easily unscrewed and disconnected? Has anyone ever see such Safety add-ons?
Black cable is Motor Power and yellow cord is Brake Power. This pic is at VFD.
Lift Motor power can be easily disconnected on floor level at VFD.
Picture of Lift Motor and motor pecker head.
In the last picture this is how the cable was disconnected when I lowered Hoist and it fell. This was the Backup Drive and it was not being used at the time. From the HMI the Backup Drive was accidently selected (an easy to do fat finger). When I selected “Lower Hoist” the brake released and with no power and therefore no torque on Motor the Lift fell to the ground. You can see the Main Drive in the background.
thank you
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