Best pull ever!!

[kwired]

While you have to look at the voltage drop you also have to look at the shunt capacitance of the wires. The shunt capacitance can prevent the open contact at the float switch from shutting the system off. Increasing the size of the control wires actually reduces the length of wire that you can have in the circuit before the shunt capacitance becomes a problem.

Depending on the actual control circuit loads the control circuit run in this thread could be a problem. Even if it is not a problem now, it may become one when the conduit fills with water.

Take a look a the third document down on this page.

I'm sure type of control equipment will make a difference, but have been using 14 or 12 AWG for irrigation controls for many years with distances much longer then mentioned in OP with little troubles - but most of those instances the load controlled was basic magnetic contactors/relays, I imagine some solid state equipment may have some trouble in some of those cases, maybe an additional load like a shunt resistor would help when that is a problem.

Just thought I would post what I did today. Installed 860 feet of 2 inch pvc in a straight line with one pull box in the middle. Then pulled in 2, yes 2, #14 stranded wires!! Sure it was up a hill, but it doesn't get any easier than that. It was the wires for a float switch in the water tank, but the owner wanted to put in larger conduit in case he wanted to run power to the tank site in the future. I wish all my wire pulls were like this!

Only two wires - must not have needed an equipment grounding conductor for this application?

 

[don_resqcapt19]

Better yet, install a spare conduit equipped with a string. That way future wires don't damage yours, no matter what happens when they go to use the spare.

In underground PVC installation, the conduit is a much smaller portion of the total cost of installing the feeder. The largest part of the cost is digging and backfilling the trench. Not to mention the inconvenience of leaving the trench open from when it is dug, to when it is inspected.

If the raceway is PVC I still won't use a string...PVC cuts too easy. For me it would be a #10 or 12 wire or a 1/4" polypropylene rope. (the rope is normally cheaper than the wire, but I almost always have wire on hand and may not have the rope on hand)

 

[10fords]

I'm sure type of control equipment will make a difference, but have been using 14 or 12 AWG for irrigation controls for many years with distances much longer then mentioned in OP with little troubles - but most of those instances the load controlled was basic magnetic contactors/relays, I imagine some solid state equipment may have some trouble in some of those cases, maybe an additional load like a shunt resistor would help when that is a problem.

Only two wires - must not have needed an equipment grounding conductor for this application?

No ground needed- just a simple 2 wire float switch in pvc conduit the whole way.

 

[Smart $]

No ground needed- just a simple 2 wire float switch in pvc conduit the whole way.

That by itself does not qualify for no-ground-wire wiring.

 

[ActionDave]

That by itself does not qualify for no-ground-wire wiring.

There's just two wires in the float and PVC conduit. Where does the green wire go?

 

[Cow]

There's just two wires in the float and PVC conduit. Where does the green wire go?

Exactly.

 

[ptonsparky]

There's just two wires in the float and PVC conduit. Where does the green wire go?

To the green screw, otherwise you're home free.

 

[iwire]

To the green screw, otherwise you're home free.

What green screw?

 

[ptonsparky]

What green screw?

The one on the metal frame of the float switch. Often there are two, unless they vibrated loose from banging around in the service truck for the last 5 years.

I was being sarcastic. I gave him the benifit of doubt, that if he saw a green screw, he would have a green wire.

 

[iwire]

The one on the metal frame of the float switch.

:thumbsup:

I was thinking and I bet Dave was too of the simple float switch on the end of a rubber cord. No metal parts, nothing to ground.

That said the last time I did something like that I pulled a green out of habit even though there was no place to land it and it was just 9 VDC.

 

[kwired]

No ground needed- just a simple 2 wire float switch in pvc conduit the whole way.

I had to bring it up, whether or not one is required depends on more then just one condition. If you have over 50 volts in this particular circuit those chances of needing an EGC do increase, and you need to ensure there is nothing there that needs to be connected to an EGC in that situation. I may not pull one for a short run but a long run like you have I would take a harder look when deciding. All it takes is for someone to replace that switch with something with a metal housing and now you likely need the EGC.

 

[10fords]

:thumbsup:

I was thinking and I bet Dave was too of the simple float switch on the end of a rubber cord. No metal parts, nothing to ground.

That said the last time I did something like that I pulled a green out of habit even though there was no place to land it and it was just 9 VDC.

That's the one. Hangs inside the water tank and shuts the well off when it's full. Nothing to ground even if you wanted to! simple yet effective.

 

[10fords]

That by itself does not qualify for no-ground-wire wiring.

Please elaborate. If there is nothing to ground in the raceway or the device why would a EGC be required? I tend to overbuild things, but not if they will never be used.

 

[iwire]

Please elaborate. If there is nothing to ground in the raceway or the device why would a EGC be required? I tend to overbuild things, but not if they will never be used.

If it was line voltage it would need an EGC if there were metal parts involved.

 

[ActionDave]

:thumbsup:

I was thinking and I bet Dave was too of the simple float switch on the end of a rubber cord. No metal parts, nothing to ground.....

Yes I was.

The one on the metal frame of the float switch. Often there are two, unless they vibrated loose from banging around in the service truck for the last 5 years.

I was being sarcastic. I gave him the benifit of doubt, that if he saw a green screw, he would have a green wire.

I got ya. I have a hard time clicking on the smilies sometimes and hope that someone catches on.

 

[Smart $]

Please elaborate. If there is nothing to ground in the raceway or the device why would a EGC be required? I tend to overbuild things, but not if they will never be used.

Others have already covered it.

 

[kwired]

Please elaborate. If there is nothing to ground in the raceway or the device why would a EGC be required? I tend to overbuild things, but not if they will never be used.

2 inch raceway for two 14 AWG conductors - maybe should have considered 3 inch raceway just in case you need to someday pull in an EGC

 

[ritelec]

Good thread.


I doubt they make 3 or 4 foot electrical raceway

Would the 3 or 4 foot drain piping they use work?

If so

You could the install fluorescents in it like they do in duct work for horror movies.

Carol Ann Go to the float switch.

 

[kwired]

Good thread.


I doubt they make 3 or 4 foot electrical raceway

Would the 3 or 4 foot drain piping they use work?

If so

You could the install fluorescents in it like they do in duct work for horror movies.

Carol Ann Go to the float switch.

3 foot is a little small, but 4 foot is starting to get big enough to be a usable "tunnel". You also need to consider the space any equipment you install takes up in such a tunnel - not quite same as calculating raceway fill though, plus you would need to ensure there is sufficient fresh air for any workers in the tunnel.

 

[GoldDigger]

3 foot is a little small, but 4 foot is starting to get big enough to be a usable "tunnel". You also need to consider the space any equipment you install takes up in such a tunnel - not quite same as calculating raceway fill though, plus you would need to ensure there is sufficient fresh air for any workers in the tunnel.

Not to mention how everything would work if you turned it upside down.