Running line for washing machine, help needed.

[PeterA]

Hello. I am installing a washing machine in a concrete out building on our property. I have some  basic electrical experience back in the US, but new to doing this.

I plan on running the wire from an existing outside, covered outlet that is on a 20 amp breaker. I will run the wire underground in pvc  20 meters to the out building. The pcv pipe will be sealed with pvc glue. The drain pipe will exit the building via another pipe and into a ground soaker at least 3 meters away from the pipe with the electrical.

I want the thing to be safe first. I have a 20 amp on-off switch 1 meter from the machine, and next to that is an outlet to plug the machine in to.

The outside outlet is 2 prong.

Where in the line do I install a GCI? Do I need a earth ground? With the wire being 20 meters, what gauge should I use?

Is my whole line of thinking doable?

Anything missing? Thanks!

[Crossy]

I would instal a 3-pin outlet, most white-goods needs a ground. You can put in a local rod if you don't want to run a ground from the house.

 

Does your house already have a Safe-T-Cut device (RCBO) look for a "Test" button, if so you already have earth leakage protection. If not you should consider installing a whole house unit for your safety (vital if you have electric water heaters).

 

If you only want to protect the underground cable from earth faults you can get cheap (500 Baht) stand-alone RCBOs from all the big-box places, install it at the feed end of the underground cable.

 

For a 20m run you can use 2.5mm² cable.

 

If running underground your pipe WILL get filled with water no matter what you do, so a wet locations cable is recommended, use NYY 

http://www.bangkokcable.com/product/backoffice/file_upload/131007_33-450!750V 70C NYY-1C.pdf

 

 

[bankruatsteve]

If your washer has a two prong plug, just run a wire from the washer chassis (if it's plastic, nevermind) to the outbuilding steel and that should be good for grounding.  

[PeterA]

20 minutes ago, Crossy said:

 

 

I have RCBO in the house. The house is just a year old, and we did all the current safety devices available for the most part. I was hoping to not use NYY, as it is hard to find here in the country. But I will go hunting for it today.

 

A local rod, can you give me some specifics please? Can I use a piece of rebar? How far int the ground? Copper wire to the ground?   Thanks!

 

 

Quote

 

 

 

[Crossy]

If you can't get NYY then the regular "flex" type cable will be ok for a considerable time, it's insulated and sheathed just not rated as water resistant.

 

Whatever you do don't use the single-insulated THW often used for indoor wiring (and overhead although it's not rated for it), any damp and THW will fail quickly.

 

You can either run 3-core cable bringing the ground from the house, or bash in a 1m copper-clad-steel rod near your washing machine outlet. Use at least 2.5mm² to link the rod to the outlet. 

[PeterA]

2 hours ago, Crossy said:

If you can't get NYY then the regular "flex" type cable will be ok for a considerable time, it's insulated and sheathed just not rated as water resistant.

 

Whatever you do don't use the single-insulated THW often used for indoor wiring (and overhead although it's not rated for it), any damp and THW will fail quickly.

 

You can either run 3-core cable bringing the ground from the house, or bash in a 1m copper-clad-steel rod near your washing machine outlet. Use at least 2.5mm² to link the rod to the outlet. 

Not sure what a flex type cable is. Should the wire be stranded or single core? I was originally thinking  about using an outside extension cable, run in PVC. I guess not a good idea,? I live in Phimai. Have to go to Korat to get NYY.

The existing outlet was jumped off an interior outlet that is rarely used. The interior one has a ground, but the "electrician" handyman that hooked up the external plug did not use the ground. But, I can run a wire to the metal frame of the building. Easy to do.

[sometimewoodworker]

1 hour ago, PeterA said:

Not sure what a flex type cable is. Should the wire be stranded or single core? I was originally thinking  about using an outside extension cable, run in PVC. I guess not a good idea,?

Stranded

 

VCT is OK in conduit though not this size, you probably need 3 x 2.5sq.mm. But unless the run is short you should probably use LDPE or HDPE as you probably will not need to have any joins in the pipe and it is quite a bit cheaper also far more UV resistant than PVC.

[PeterA]

3 hours ago, sometimewoodworker said:

Stranded

 

VCT is OK in conduit though not this size, you probably need 3 x 2.5sq.mm. But unless the run is short you should probably use LDPE or HDPE as you probably will not need to have any joins in the pipe and it is quite a bit cheaper also far more UV resistant than PVC.

I already have the PVC left from other work, hence my reason to use it! I believe most washing machines run less than 6 amps. Is 3 x 2.5 overkill? The run is 20 meters.  Thanks.

[bankruatsteve]

11 hours ago, PeterA said:

I already have the PVC left from other work, hence my reason to use it! I believe most washing machines run less than 6 amps. Is 3 x 2.5 overkill? The run is 20 meters.  Thanks.

2.5mm² is what you need.  Don't go any smaller.

[Crossy]

The problem with using smaller cable is when uncle Somchai plugs his welder into your "washing machine" outlet.

 

You COULD go down to 1.5mm², but you would need to put it on a 16A breaker.

 

[PeterA]

So I have my 3 conductor run from the house, and in the house that line is on a GFI (Thai version).

When I get to my shed where the washer is, I have a 2 conductor breaker. Do they make a stand alone 3 conductor breaker, or do I need to use a ground to the metal frame of the building? The washing machine has a three prong cord.

Thanks!

[PeterA]

On 8/15/2018 at 10:43 AM, Crossy said:

I would instal a 3-pin outlet, most white-goods needs a ground. You can put in a local rod if you don't want to run a ground from the house.

 

Does your house already have a Safe-T-Cut device (RCBO) look for a "Test" button, if so you already have earth leakage protection. If not you should consider installing a whole house unit for your safety (vital if you have electric water heaters).

 

If you only want to protect the underground cable from earth faults you can get cheap (500 Baht) stand-alone RCBOs from all the big-box places, install it at the feed end of the underground cable.

 

For a 20m run you can use 2.5mm² cable.

 

If running underground your pipe WILL get filled with water no matter what you do, so a wet locations cable is recommended, use NYY 

http://www.bangkokcable.com/product/backoffice/file_upload/131007_33-450!750V 70C NYY-1C.pdf

 

 

Crossy,

 I have my 3 conductor wire run from the house, and in the house that line is on a GFI (Thai version).

When I get to my shed where the washer is, I have a 2 conductor breaker. Do I add a ground wire at the breaker to run to the metal frame of the building?  Not sure how to pass the grounding to the plug the washer will use.  The washing machine has a three prong cord.

Thanks!

[Crossy]

To get the ground past the breaker just join the wire at the side of the breaker, no need for it to pass through the breaker.

 

No real need to connect to the building steel as well.