motor starting

arnettda

Senior Member
have a couple motor control questions.
I have a large lumber saw that has a conveyor that came with the saw. the conveyor is not long enough so the company added there own 2nd conveyor. the supplied conveyor is controlled and powered from the saw.
I can power added conveyor from a separate source but would like to control it from same switch as the supplied conveyor.
my two options
#1 add a motor contactor with a 480 volt coil so when the 1st conveyor starts the 2nd conveyor will as well.
#2 steal 120 volt control power from control panel and run it to the contactor for the added conveyor.
Are both legal?
will added load of coil draw cause issues with motor loads. ?
using 480 volt coil power is the easiest option for the way things are wired?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I don't see anything that would be in violation of the code in the options you mentioned. But as always, the details of how you implement them matter.

I can't tell you if the added load of the options you mentioned would create any problems since I have no idea how much margin you have and what the added load would be.

personally, I would be inclined to add an aux contact to the original conveyor motor starter and use it to control the new conveyor ( I know, a third option).
 

gar

Senior Member
210630-1004 EDT

arnettda:

How much power do you think a relay coil draws? Insignificant relative to most motors. Without making any measurements my guess is that a #2 motor starter would be less than 10 W, and 40 VA. Most small motors are around about 1000 W / HP.

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arnettda

Senior Member
I don't see anything that would be in violation of the code in the options you mentioned. But as always, the details of how you implement them matter.

I can't tell you if the added load of the options you mentioned would create any problems since I have no idea how much margin you have and what the added load would be.

personally, I would be inclined to add an aux contact to the original conveyor motor starter and use it to control the new conveyor ( I know, a third option).

I like that idea but then I would have a separate power source in the original control panel.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I like that idea but then I would have a separate power source in the original control panel.
Use orange wire. Add a label that indicates orange wiring is not disconnected by the saw disconnecting means.

Incidentally, you would not have a separate power source in the original control panel. Just a couple of control wires that are powered from outside the original control panel, which is pretty common.
 

arnettda

Senior Member
Use orange wire. Add a label that indicates orange wiring is not disconnected by the saw disconnecting means.

Incidentally, you would not have a separate power source in the original control panel. Just a couple of control wires that are powered from outside the original control panel, which is pretty common.
so then I would use a starter with a 480 volt coil and just use the power supply that is supply the second motor?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
so then I would use a starter with a 480 volt coil and just use the power supply that is supply the second motor?
that is one option. personally, I would get a starter with a lower voltage coil and just add a transformer or power supply for the control voltage.I am not a big fan of 480 Volt coils.
 
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