motor controls

[Joe Rocker]

I am a school teacher, and I am trying to prepare my students for a contest called Industrial Motor Controls. I have like a fiberglass panel, contacters, relay, plus the contest uses half inch conduit. Here is my question, do I need to attach a grounding bar inside this box? Reason I ask is I am using metal boxes that have the green ground screw in them. This is only a contest but it should reflect how it would be done in the real world. Thank you in advance, I appreciate your help.

 

[petersonra]

I am a school teacher, and I am trying to prepare my students for a contest called Industrial Motor Controls. I have like a fiberglass panel, contacters, relay, plus the contest uses half inch conduit. Here is my question, do I need to attach a grounding bar inside this box? Reason I ask is I am using metal boxes that have the green ground screw in them. This is only a contest but it should reflect how it would be done in the real world. Thank you in advance, I appreciate your help.

are you planning to paint the ground bar green? if not, what good would it be.

 

[Smart $]

are you planning to paint the ground bar green? if not, what good would it be.

It would facilitate the splicing of any grounding and bonding conductors.

It doesn't need to be painted green. :happyno:

 

[jap]

It would facilitate the splicing of any grounding and bonding conductors.

It doesn't need to be painted green. :happyno:

I'd second that.

 

[petersonra]

How will the electrons know it is a ground bar if it is not green?



Seriously, if you want to put in a ground bar for convenience, that is fine. It is not actually required though.

 

[jap]

How will the electrons know it is a ground bar if it is not green?



Seriously, if you want to put in a ground bar for convenience, that is fine. It is not actually required though.

The same way Lightning knows where to go even though the grass is dead.

 

[fmtjfw]

I am a school teacher, and I am trying to prepare my students for a contest called Industrial Motor Controls. I have like a fiberglass panel, contacters, relay, plus the contest uses half inch conduit. Here is my question, do I need to attach a grounding bar inside this box? Reason I ask is I am using metal boxes that have the green ground screw in them. This is only a contest but it should reflect how it would be done in the real world. Thank you in advance, I appreciate your help.

I organize the Motor Controls Contest in WV. I judge as well. I am perfectly happy if the contestant wirenuts, or crimps all the grounding wires together. I require that all non-current-carrying metallic items (boxes and DIN-rail) be effectively grounded. If you want to be fancy you can get a bunch of green/yellow terminal blocks for a piece of DIN-rail. These bus themselves together when you mount them and tighten the mounting screw. This would generally be the case in a "real" motor control panel. You can also get an "add-on" neutral or grounding bar for a panelboard and use it as your grounding bus.

The cost of components for each contestant is generally so great that we try for simple, compliant methods.

(our "kit" consists of 4 pushbuttons, 1 rotary switch, 1 pilot light, 2 small IEC motor starters, random S1, S3, S4 switches used as limit switches, float switches ..., edison fused feed box, and lamp holders as "motors" plus consumables (wire, wirenuts, wire markers, ...) totally about $350/$400 per contestant)

Good luck for your student(s)!