Electrical Useage

A timer switch or timer relay? For the 480 motors it would not be in the 480 line but in the start stop station control circuit.

As stated in #1, timers will work, and should be easy to wire into the start circuit. There are also proximity sensors that could sense the presence of a person or people in selected areas. This would even shut off the conveyor at lunch breaks. just be sure that the start signal is not automatically turned on when a person returns to the area being monitored. good luck.

Jeez there must be an isolator switch..it just needs someone to switch it off.

It doesn't need complication..it needs education.

There must be a foreman/site manager or someone responsible!

Del

Guest,

I like the load sensing relay, because it is independent of the conveyor's layout or components. As others have noted, starting it up automatically is something to be careful with.

Another possibility is a photo-eye which is aimed down the length or at a shallow angle across the area where items are loaded onto the conveyor. When a box or tote is put on, it breaks the PE beam, which will reset the off-delay (if the conveyor is running) or start it (if it is off). PE's are readily available with built-in timing functions, so the output can become the maintained input to run the motor(s). One could also add a Hand/Off/Auto switch to this so the conveyor can be kept on, or kept off, or be under PE control. You wouldn't need to worry about accuracy in setting a motor load sensor and you wouldn't need a separate means of starting it. Only concern would be to ensure that a nearby conveyor's PE didn't happen to falsely trigger the wrong conveyor (it has happened to me when starting up automatic systems).

--JMM

As has been previously suggested a simple electro-mechanical timer, controlling a relay would be the easiest and, probably, cheapest way to achieve your desired effect. I have such a timer controlling the fan over my wood stove in the garage, and it would be very simple to use it to control a relay with which to switch higher voltage.

Del the Cat said it best: TURN THE THING OFF!! There has to be someone in charge of the plant.

Unless people wander in off the street and just start working.

Pay the last man there a little extra to turn off the lights and the conveyor when he leaves. You will more than make this up in savings on electricity.

Dragon

add timers to control circuits

There are two ways of doing it, and both have been mentioned on some of the responses.

Option one: Educate the crew to swith off the conveyor as they leave the process area.

Option two: The use of a time delay on the control circuit would help to swith off the conveyor after a pre-set time when product flow is not detected.

The first is the least expensive of the two, and does not require any equipment to be scheduled down for the modification of controls.

If you are going to switch the conveyor off automatically you may as well have it turn on on demand as well, if you have a sensor mounted each end of the conveyor to sense product coming onto and leaving and connect them to a vsd with a timer added to the out feed of the conveyor to time product off the conveyor you can automate the process, just need to remember safety. Or get staff to do their job.

A NC sensor with a gate at the end of the conveyor! If the boxes are not taken off the conveyor before they reach the gate, the sensor goes open thus cutting the hold in circuit! To re-arm, remove the box and press the start button!

This is what we do with the tomato conveyers!

Truman, Brilliant, and in the long run probably cheaper than paying some one extra to shut it off.

Dragon

All the control cicuits mentioned so far are part of specific requirement, which varies as per the need. It is said necessity is the mother of invention. First spell out your clear requirements and solutions flows out automatically. Human control is always last say in any machine control.