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Connect washing machine to GFCI circuit for shower water heater?


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Posted

I live in a condo which has a 30 amp GFCI circuit dedicated to the water heater for the bathroom shower.  I recently bought a new washing machine which requires a 15 amp circuit, and I'm considering having it installed with a connection to the 30 amp water heater circuit, but I'm wondering if I might be creating any problems.  My biggest concern is whether I'm putting my safety at risk by standing in the shower with a water heater GFCI circuit breaker which might somehow be compromised by this change. 

 

I suspect I'm not the first person in Thailand who's considering attaching a large appliance to the GFCI shower water heater circuit.  Does anyone know if this represents a problem or a danger?

 

Many thanks (in advance) for any input!

 

 

Posted

Semantics OK?  It's unlikely that you have a point of use GFCI on your shower heater (it should have it's own "ELCB").  Maybe it's also protected by a RCBO for that circuit or RCBO for the entire unit?  In any case, you can tap into that circuit if you really want to but a "normal" 20 amp grounded circuit will be OK for your washer.

 

Even if you do tap into the shower circuit, the shower unit's ELCB (or even if it does have GFCI) will not be affected nor protect the washer from earth faults.  A front end RCBO will.

Posted

Suggest grabbing a photo with your mobile phone of your CU / Breaker Box and where you want to add the branch circuit to feed the new washing machine and posting the image here.

 

As @bankruatsteve elaborated to, actual GFI/GFCI are not normally found in Thailand.

Generally you'll find RCD (Residual Current Devices) either as up-front main breakers, RCBO as a circuit breaker, or sometimes as an external breaker protecting / isolating a wet-area device -- identified by their 'Test' switch.  

 

Most on-demand shower heaters have the protection circuit built-in to the unit and  you'll find only normal double-pole breaker nearby used to isolate the device.

 

I think @bankruatsteve is thinking you're tapping into the back-end of the water heater (where you'd have no RCD protection), but I'm under the impression that you're tapping into a breaker a bit upstream, or in a CU / Breaker Box. If this is the case, then ANYTHING branched off would be protected by the RCD (if a genuinely RCD) and trip if the L/N became unbalanced.

 

My largest 12kg washing machine requires 310 watts.  What bells and whistles does your have to actually require connection to a 15A (3,300 watts) plug point?  

Posted

+++ on the above.

 

Did your washer come with a plug? If so plug it in to a convenient outlet.

 

If you need to install an outlet it would be better run off the existing outlets circuit. Branching off the shower circuit would mean you have an outlet on a 30A breaker, not going to kill anyone but the potential for overload is there unless you fuse it down with a separate 20A breaker.

 

What do the washer instructions say about power supply?

 

Posted

Thanks for the feedback, folks.  I've included here some pictures which should help explain the situation a bit more.

 

One of those photos is the spec sheet for the new machine, and another explains the installation requirements - which unfortunately, I find to be a bit vague.  For one thing, nowhere on the installation requirements sheet do I see any reference to required amperage - it only refers to total wattage, the amperage for which depends on the Power Factor, which is unknown.  I bought the machine at Power Buy, and they're the ones that are proposing it be installed on a 15 amp circuit.

 

As you can see, the existing receptacle circuits are only 10 amp, and apparently this machine requires at least a 15 amp circuit.  The machine is a front loader - and also provides hot water, which might explain the heavy power draw, even though it's only a 7kg machine.

 

You can see from the photo that the 30A shower circuit has a circuit test button, so I assumed that means this is GFCI, but I'm not sure about the nomenclature.

 

The shower water heater circuit would be tapped into, downstream of the breaker, and probably just before the water heater.   This separate branch would in fact terminate in an outlet on the wall.

 

I'm also concerned about grounding.  I see that the breaker box has a green ground wire coming into it, so I suppose this can be tapped into for the new outlet to be grounded as well.

 

All of this will be taking place in a fairly large condo building that's about 25 years old - and it's my impression that the electrical capacity for each condo is barely enough to suffice, with modern electrical loads.  My small kitchen is actually running off one of the 10 amp receptacle circuits!  The other receptacle circuit powers my TV, stereo, and desktop computer.  So, not a lot of places left to attach this washing machine.

 

Thanks again for the input!

 

 

 

 

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Posted

Is the place yours or a rental?

 

Your washer will be fine on a regular outlet, you can tee off the shower (I'd rather not) but you ought to add a 20A MCB in the line for safety, they are a couple of hundred Baht with a little box, usually sold as "Safety Breaker".

 

I'm more concerned about your box, particularly the apparent absence of 2-pole isolation of the incoming supply.

 

EDIT Where does the curly white wire from the RCBO (GFCI) go?

Posted

Not sure Crossy would agree (?)...  It looks like the wires from your #2 and #4 "Receptacle" breakers are at least 1.5 mm2 (maybe 2.5 mm2?).  If that's the case, you could swap out the 10 amp breaker for 15 or even 20 amp and then just plug into one of those with your washer.  (This because 1.5 mm2 can handle 15 amp and 2.5mm2 can handle 20 amp).  You would then have to work out a ground as I don't see where you have that.

 

If you do go into the shower circuit, you should use 6mm2 cable to the washer (then you wouldn't need additional breaker).

Posted

Oh man, that box looks lethal.

 

 

2 hours ago, Crossy said:

EDIT Where does the curly white wire from the RCBO (GFCI) go?

Yeah, I would assume this (tapped off) pigtail would be the Outgoing NEUTRAL Feed meant for the LOAD from the RDC Protection circuit. I would think the by not using it (and running the load directly to the common Neutral Bus) the circuit should constantly trip on load imbalance. Strange.

 

I'd suggest dropping in an additional breaker (if you can find one).

Posted

I'm pretty sure the pigtail is the incoming neutral for the RCBO and it looks like it goes to the ground bolt of the metalwork. It should go to the neutral bar on the right hand side of the box.

 

If it does it means the water heater is running off Live and Ground!! At least it shows it's a decent (probably TN-S) ground.

 

 

Posted
9 minutes ago, Crossy said:

I'm pretty sure the pigtail is the incoming neutral for the RCBO

Really?  Because then the Neutral output would be to the split common bus running under the breaker?

I would imagine it the other way around. 

Posted
8 minutes ago, RichCor said:

Really?  Because then the Neutral output would be to the split common bus running under the breaker?

I would imagine it the other way around. 

 

Bus under the breakers looks single, live only to me. Neutral commoning bus on the right.

 

The whole thing looks a mess and needs replacing in reality, which is why I asked if the place was a rental.

 

EDIT I wonder if that unit with the Test button is really an RCBO, could it be a VOELCB? Has it got a readable part number?

 

EDIT 2 To our OP, does the Test button do anything?

 

Posted

Matching the image to a google search for "GFCI push to test"...


 

ThaiVisa_gfci-breaker.jpg.8579d4f57f45369d6ba2b4b14a16c8de.jpg

 

GFCI circuit breakers feature a "test" button on the front that you can use to test that it's working properly.  This is the same sort of feature you find on GFCI receptacles.  After you press the "test" button you will have to reset the breaker to turn the circuit back on.  

The curly white wire pre-attached to a GFCI breaker must be tied into your breaker panel neutral bar.  A GFCI circuit breaker will have two load terminals: One for the Line and one for the Neutral feeding your circuit.

 

Note: Text and image stolen from the Internet

 

@funlovinkid,  can you take and post another pic showing the connections of your "GFCI". And, carefully, verify what the white pigtail wire is connected to (if anything). 

Posted

Quick answer to your recent questions: the condo is a rental.  I don't own it, but I'm moving in there next week.  I specifically asked for a front-loading, hot water, washing machine to be installed, which is how I got to this point.  The owner agreed to pay for the new machine in exchange for my willingness to agree to a 1-year lease.

 

Using the "Test" button on the "GFCI" breaker does in fact trip the breaker, I've already tried it.  The breaker switch does need to be reset afterward: first completely off, then back on.

 

A new wrinkle: it's possible that an entirely new, dedicated circuit can be installed for this machine.  I'll get an answer from the technician tomorrow.  His answer will depend on whether he feels his access to the false ceiling will allow him to pull new wires to/from the breaker box.

 

I'll make a point to answer your other questions tomorrow (with pictures) after I gain access to the rental unit.

 

Thanks again to all!

 

 

Posted

Okay, I just came back from checking, and the curly wire goes nowhere - it's just terminated with electrical tape.  I included some images of the breaker itself and its connections to the panel.  Based on the label on the breaker, apparently it is GFCI.  Hope this helps.

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Posted

GFCI it may be, but wired like that it won't be doing any shock protection. I must admit I'm a little surprised the Test button works with no neutral connected.

 

I'm also confused by the left hand terminal bar, it should be the ground (neutral is on the right) but the heater neutral appears to go to it. Is that bar connected to anywhere else?

 

The pigtail (GFCI incoming neutral) should go to the neutral bar on the right of the unit. The heater neutral should go to the upper (unoccupied?) terminal on the left of the GFCI.

Posted

I know it's a rental, but seeing you're renting for a year, it may be better not to try and accommodate expansion, but install a new Consumer Unit . They seem to be everywhere nowadays. That would give you a main on/off breaker, RCD, and a breaker for your new washer.

 

Sent from my SM-J700F using Tapatalk

 

 

 

 

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