Topic: Running S17 or T17 from the dryer plug in US (Read 212 times)

The real fun part is what happens if/when the ground opens. Let's say you didn't screw down the ground properly in the circuit box and you had a 120v motor in the appliance connecting to one hot leg and the ground (which is also attached to the frame of the washing machine for safety). Now 5 years later the ground opens. Maybe thermal expansion loosened it, maybe the small amount of current being used by the motor browned the wires a bit more each day till current would not flow. This happens.

You now have a situation where the power goes from the hot leg, through the timer motor in the appliance, and dead-ends at the ground as there is no path back to neutral. Thus the whole dryer metal box is now "hot" with the current from the dryer motor trying to find a place to go to neutral. Now you touch it, while standing in that wet puddle next to the washing machine.

You have now become the path to "ground". And since 100ma at 120v is enough to kill a person you had better hope that motor can pass less than 100ma.


(Electrical safety, the fatal current (1987), Ohio State. Retrieved from https://www.asc.ohio-state.edu/physics/p616/safety/fatal_current.html)

That is the problem. If the motor went back to the breaker panel on a neutral and the neutral opened then the frame of the dryer would not be hot as it is connected to neutral and not the motor. If the ground opened up then the frame of the dryer would still not be hot as nothing is connected to it (however if a ground fault developed say in the dryer motor the frame could become hot which is why you ground it). The voltage differential is one thing, but if the frame ground is expected to carry a load and the ground wire becomes disconnected you basically have a hot stove waiting for people to touch it.

Interesting stuff.

since the s17 and the t17 simply need two hot 120= 240. and a ground.

my instructions should work. for one miner. see below if you want to run both.

my common/ground bar in main breaker has one wire to cold water copper house feed. one wire out back to a 10 foot copper pipe in the ground.  and one wire to the feed from the power company.

I am pretty sure my instruction to the op is safe and he can do a single s17 the way i said.

for two units.  he could grab the pdu i linked and maybe run the s17 and the t17 off the single circuit.

he only need replace the plug on the pdu with a l14- 30 p and hook the pdu to the dryer receptacle.

a t17 and a s17 use about 4500 watts the linked pdu should work.

he would need four of the c13 to c20 cables  to do the two units.  he may need to run the s17 on medium speed just in case.

The difference is that a neutral (common) is intended to carry power and a ground is intended only for safety in the event a line contacts a metal chassis. Yes both tie together inside the panel but that must be the only place they are connected. It is what makes a neutral, well, neutral with only a small voltage difference (that depends on the load & wire size) between the other end of the wire and any ground you find.

As lightfoot said, older electric dryers and ovens often used to improperly use the ground to give 110v to timer motors & light bulbs. It was only allowed by some local electric codes  because said loads draw very little current so *in theory* the combined neutral/chassis ground *should* have very little voltage difference on it referenced to any nearby water pipes or any other grounded metal.

Of course *in theory* means that it is not always the case so a dedicated neutral is now mandated when a high line system needs a neutral connection to provide lower control or aux power.

The reason there is a common on 240 volt dryer plugs is due to some old stupidity in the dryer market. Way back in the day dryer timer motors were simple 110v motors that would run the clockwork that makes up the dryer timer. However the dryers were sourced with two wire plus ground 220 (240) volt lines. So the hot (hah!) solution to the problem was to wire the timer, light, things like that up to one leg of the 240 and ground. That gets you a nice 120v.

However this is WRONG! It means that ground is carrying current during normal operation which it should never do. Thus the solution was to run a discrete wire to neutral alongside the ground wire to handle the 120 volt hotel loads on the dryer. The other solution would be to include a 240-120 volt transformer (a small one) in the appliance, but that would raise construction costs by a dime and we can't have that....

These days, as dryers and such are electronic, the switching supplies that run the electronics can take either 240 or 120 so the third wire is not really needed anymore. Technology marches on but the 4 wire outlet remains.

And yes, they both terminate at the breaker box in the same location. Ground in a house is the common busbar which is usually bonded to a nice pipe or grounding rod going deep into the center of the earth.

I remodeled my basement bedroom it has the main panel I did a 60 amp to the garage  the garage now has a sub panel with 2 30 amp breakers.

There's plenty of 240v "sources" within your breaker panel.   

Why not just run a new 240v circuit(s), and do it the right way?

A 2-pole 20A breaker, some 12-2 wire, and the right outlet https://www.amazon.com/Leviton-5461-W-20-Amp-250-Volt-Receptacle/dp/B0050T2D56.

Then you can use the proper cords. 

I have one circuit per miner.

When I ran out of room in the main panel, I decided to wire up a 100A subpanel and put all the miner circuits in there

they can last 20 years or 20 minutes.

but when and it they ever get pulled loose they are a live wire with no protection.  Which is why they are a  safety hazard.

If I recall the photo where I mentioned it was unsafe you had multiple racks 6 feet high with multiple connections like the one in the photo above.

Not to be off topic as this is on topic.  I clearly told op to be careful he is using lethal amounts of  voltages and amps.

I would not want to splice multiple units and do what you did.  I would have purchased this pdu

https://www.ebay.com/itm/HP-228481-002-EO4501-Modular-PDU-Power-Distribution-Control-Unit/372792150975?

and replaced the plug with the l14-30r  and plugged into the dryer plug.

op wanted 1 unit  an s17 or a t17  so I told him a way that I think is safe and cheap.
I told him I am not trained in the field and it is dangerous to do this work.

if he mods the pdu with the dryer plug and runs 2 units pulling   about 4.4kwatts he should be okay.

Common/Return is often erroneously called "Ground"...it is a VERY bad habit.

The whole purpose of a "Ground" wire is to NOT BE CONDUCTING the load..to be available if a short happens to contact the appliance and make it LIVE/HOT, the "Ground" is meant to be attached such that, if the short makes a connection with an appliance and it then becomes "LIVE" or "Hot"... the "Ground" will THEN ACT as a return for the circuit rather than having the current use the fool who is touching the unit as a return to complete the circuit. It is this very factor which makes AC MUCH safer than DC and was most dramatically demonstrated by Tesla during the current war with Edison, Tesla connected himself to a 1 million volt GROUNDED AC circuit.
I've done this myself in University with 110v and it's still quite the tickle.

Many have experienced this an not even realized it....If you ever touched an electric thing and felt a terrible tingle but not a real hard zap shock it was probably as I described. It frequently occurs from wrongly splicing or connecting wires, especially when mistakenly using the GROUND as a conductor.


Phil said that 3 years ago...and it is the same connection ....still fine...still safe...But I DO check frequently and have re-wrapped the outer protective layer once as the tape does will slowly loose it stickiness and unspool.
They are crimped with metal and soldered and tinfoil wrapped and shrink wrapped and then tape wrapped....They just are not in an box...they are BETTER and safer splices than required for code.

@Philopolymath

Your wiring looks like a fire hazard is on the way.

Why don't you use crimp connectors and cover it with heat-shrink tubing?

So what I'm saying is that do it by the code or don't do it at all.
That is my motto.

yeah but last I looked on my panel  both common and ground connect to same bar.

so what's the difference?

if you take a l14-30 plug

put the green wire to the l prong

and the white and black to  the hots   won't this work?


the 2 hots form the c19-c20 cable  and the ground/common

In my home my breaker box has 2 120volt hots and a common/ground bar

when I wire 120 I do black to one hot 120 then both the  white and bare ground to the common/ground bar.

when I do 220

I do 1 to hot 120
I do 1 to other hot 120
I do 1 to common/ground bar

I don't do 4 wire 220 wiring

which would be

1  to hot 120 A
1 to hot   120 B
1 to common /ground bar
2 to common /ground bar.

since his gear will use a 3 prong receptacle and the c19 to c20 is 3 wire

you wire to the 4 prong

1 to the hot
1 to the other hot

1 to the L shape prong   which I called a ground.
0 to the 4th spot.

both the L shaped prong and the 4th spot will go to the common/ground bar.

so whether you call it a common or a ground in either case they lead to the same spot.

NO..there is NO ground used on 220V  Single phase home lines in N.A.....they use 2 hots ( usually a black and white/red of at least 12-14 guage for 30amps 10-8gauge for 40amps)  each Hot then shares a "COMMON" usually green. I have plenty of experience using dryer and stove plugs spliced to run 30 amp and 40 amp breakers. I ran 4x S9's off each 30amp breaker at times running up 24 S9's for 180 amps off of 6x 30 amp breakers on a 200amp. panel. Splicing the open wire end of 4 C-19 plugs to open wire of a Stove/dryer plug can be tricky if trying to fit all lines into a large marrette. I use large marrettes but also make damn sure all wires are well adjoined and soldered and then wrapped in tin foil BEFORE inserting into a marrette then shrink wrap, very very well reinforced so the splice can't be accidentally pulled apart and of course then well insulated with electric tape. In 3+ years I have never had a short or break or a connection even get hot. I still use this set up to run S9's as space heaters and for testing new gear at home before sending off to the Host.



Note that with most heavy gage wire the ground is NOT counted as a Conducting wire...In my case the dryer plug has green for ground (not used) and red and black for hot ...White for common/return. So I had to be sure the match the C19's correctly. On my PSU C-19 plugs the GREEN is common/return.

https://www.amazon.com/Miady-L14-30P-Generator-Industrial-Grounding/dp/B078BNBYXR

10 bucks

so {monoprice  2x 13 to  c20}  >>>> {mono price c19 to c20}  >>>>  {amazon plug}

you cut the c20 on the middle wire   and attach hot hot ground to the l 14- 30 plug

20 bucks maybe 30.

you need to find a diagram on how to wire a l 14- 30 plug  with hot hot  ground

Note legal disclaimer : It is mechanically sound plan.  But I do not know your code for your state.

using 240 volt 30 amp power circuits can kill you maim you or your loved ones.  so the work is on you not me.

I am self taught via years of practice so if you do what I suggest here it is on you to do it right.

run s17 or t17 or s17 pro

Second note
s17e
s17+
t17e
t17+

all pull a shit ton of power over 3000 watts they are borderline to use with the 2x c13 to c20 spilt cable.

I do run 1x t17+
I do run 2x t17e

all three run hotter then I like and I will not buy them any more.

OK, thanks.
The dryer is 14-30, though (four plugs, one L  shaped).
Maybe more splicing needed.

that is an easy hack   buy these two

https://www.monoprice.com/product?p_id=35118

note picked 6 ft  there are shorter and longer.

https://www.monoprice.com/product?p_id=35060

so 8-12 bucks

cut the end end of the c19 to c20

splice proper plug

since many plugs are around I won't link

The oven and dryer are the only sources of 240V for most in US (residential).
Were you able to hack it? If so, recommend the needed cords/plugs. Thanks.
I was able to find a solution, but the costs are about $160-170.
Maybe there is something better.