Running power to a machinery pit in garage

[saabman]

I am building another bay on my garage to house a AWD Dyno. The Dyno requires to 2 30 AMP circuits. When the foundation/pit/floor was poured a put a 4 inch PVC pipe in the concrete to give me access to the pit without running on top of the floor.

The PVC pipe will also carry 1/2 braided air line.

When I get the to pit wall I plan on running EMT around the high perimeter of the pit. The pit has a drain, and I do not anticipate any water in the pit.

Not seen in the photo below is the vertical section of PVC that runs up the interior wall and the 90 degree elbow that runs in the wall. So from the panel to the upper 90 elbow I will be running in the 2x6 wall.

Can I run bare 10/2 w/ground from the panel to the EMT (perhaps stuffing a bit of EMT back in the horizontal section of PVC and "T" ing it at the side of the wall.

 

[wyliesdiesels]

nm-b aka Romex (I assume thats what u meant by "bare 10/2 w gnd") can be run in conduit in dry locations only.

U could use NM-b for interior section of conduit and then transition to THWN for the outside run in a j box on the inside.

But that is more work than just using THWN for the whole run. Plus NM-b can be a bare pulling through conduit.

I would use #10 THWN, instead of 10/2 NM-b, for the entire circuit.

 

[zmaxmotorsports]

nm-b aka Romex (I assume thats what u meant by "bare 10/2 w gnd") can be run in conduit in dry locations only.

U could use NM-b for interior section of conduit and then transition to THWN for the outside run in a j box on the inside.

But that is more work than just using THWN for the whole run. Plus NM-b can be a bare pulling through conduit.

I would use #10 THWN instead of 10/2 NM-b

 

[saabman]

The Dyno frames have twist lock connectors. So I am planning on terminating the branch circuits with twist lock receptacles and running 10/2 w Ground SO cables from receptacles to machine. Does this change the type of cable to run. So are you suggesting THWN in EMT running in high in the pit wall perimeter

 

[wyliesdiesels]

Yes run THWN from the panel to the outlet. At the outlet u can use the SOOW. Make sure to use water proof in use covers!

 

[simpler=better]

x2 use water tight connections on everything.

You don't anticipate fluids in there, but when a car throws a rod and dumps a couple gallons of coolant/oil/etc on your wiring you will be glad you spent the extra couple bucks on watertight parts.

 

[saabman]

The pit is 28.5 inches deep. The electric will run within 5 inches of the top of the pit in EMT

 

[Norcal]

x2 use water tight connections on everything.

You don't anticipate fluids in there, but when a car throws a rod and dumps a couple gallons of coolant/oil/etc on your wiring you will be glad you spent the extra couple bucks on watertight parts.

Watertight connectors usually mean NEMA 4X which is either pin & sleeve connectors or Hubbell makes UL listed 4x Twistlock connectors either are quite expensive but are good choices.

 

[simpler=better]

The pit is 28.5 inches deep. The electric will run within 5 inches of the top of the pit in EMT

I hear ya, but it doesn't need to be submerged to let out the magic smoke-it only needs to hit in an unlucky way, and right after an engine blows is probably the worst time to have an electrical short.

 

[saabman]

My receptacle will be high, but the twist lock power connector L6-30 is low on the frames. So my SOOW cord will go from high to low in the pit. I will likely drive a ground rod to ground the dyno frame (although it is bolted to the floor)

 

[Norcal]

My receptacle will be high, but the twist lock power connector L6-30 is low on the frames. So my SOOW cord will go from high to low in the pit. I will likely drive a ground rod to ground the dyno frame (although it is bolted to the floor)

A ground rod does nothing for grounding your equipment.

 

[walrus]

. I will likely drive a ground rod to ground the dyno frame (although it is bolted to the floor)

Don't bother unless you think lightning is going to strike

 

[saabman]

Part of the reason for grounding is to ensure I don't have multiple ground levels (as seen by the control electronics). The Load Cells on the dyno only generate 30 mv full range.

Here is the link to the thread on my garage build which has some pictures of the machines

http://www.garagejournal.com/forum/showthread.php?t=311033

 

[wyliesdiesels]

Part of the reason for grounding is to ensure I don't have multiple ground levels (as seen by the control electronics). The Load Cells on the dyno only generate 30 mv full range.

Here is the link to the thread on my garage build which has some pictures of the machines

http://www.garagejournal.com/forum/showthread.php?t=311033

I think youre confused about the difference between equipment grounds and grounding electeodes which are 2 COMPLETELY DIFFERENT animals.

What u need is all the parts of the dynos to be bonded to an equipment ground so its all at the same potential.

As others have said, a grounding electrode wont accomplish this.

U should read this before u do anything unnecessary:

http://www.electriciantalk.com/articles/the-confusion-of-the-term-grounding/