EMO linkage simplification
View Patent ↗Disclosed herein is a simplified EMO linkage circuit that enables add-on equipment without retrofit, and eliminates the need for multi-contact EMO switches.
1. An apparatus for implementing a unified emergency machine off (EMO) linkage circuit for multiple pieces of equipment sharing energy or power hazards, the apparatus comprising:
a plurality of modules, each module is associated with a corresponding piece of equipment, and each module includes,
a switch including a corresponding switch in contact and a corresponding switch out contact:
a relay including a corresponding relay coil and a corresponding relay contact; and
a local control;
wherein the switch in contact of a first switch is coupled to a module power supply, the switch out contact of a last switch is coupled to a power return through the relay coil of each module, and each of the other switch out contacts are coupled to a switch in contact of a successive switch arranged in a daisy chain series circuit, and wherein each relay contact couples equipment power to each corresponding local control.
2. The apparatus of claim 1 , wherein when the switches of the plurality of modules are dosed the relays of the plurality of modules are powered by the module power supply and in turn the local controls of the plurality of modules maintains equipment power to each corresponding piece of equipment.
3. The apparatus of claim 1 , wherein when any switch of one or more of the plurality of modules are open module power supply to the relays of the plurality of modules is lost and in turn the local controls of the plurality of modules turn off the equipment power to each corresponding piece of equipment.
4. The apparatus of claim 1 , further comprising a plurality of diodes, each diode coupled between a corresponding module power supply of each module and the switch in contact of the first switch.
5. The apparatus of claim 4 , wherein the plurality of diodes prevent the module power supply to the relays of the plurality of modules from being lost if one of the corresponding module power supplies is off.
6. The apparatus of claim 1 , wherein the relays of each of the modules further includes an auxiliary contact for controlling power to a corresponding additional piece of equipment.